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+The Project Gutenberg EBook of Tin Foil and Its Combinations for Filling
+Teeth, by Henry L. Ambler
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+Title: Tin Foil and Its Combinations for Filling Teeth
+
+Author: Henry L. Ambler
+
+Release Date: October 8, 2008 [EBook #26840]
+
+Language: English
+
+Character set encoding: ISO-8859-1
+
+*** START OF THIS PROJECT GUTENBERG EBOOK TIN FOIL ***
+
+
+
+
+Produced by Stephen Blundell and the Online Distributed
+Proofreading Team at http://www.pgdp.net (This file was
+produced from images generously made available by The
+Internet Archive/American Libraries.)
+
+
+
+
+
+
+
+
+
+                               TIN FOIL
+                               AND ITS
+                   COMBINATIONS FOR FILLING TEETH.
+
+
+                                 BY
+                HENRY L. AMBLER, M.S., D.D.S., M.D.,
+ Professor of Operative Dentistry and Dental Hygiene, in the Dental
+              Department of Western Reserve University.
+ Member of the American Dental Association; of the Ohio State Dental
+          Society; of the Northern Ohio Dental Association;
+                of the Cleveland City Dental Society.
+
+
+                            PHILADELPHIA:
+                  THE S. S. WHITE DENTAL MFG. CO.,
+                               LONDON:
+                    CLAUDIUS ASH & SONS, Limited.
+                                1897
+
+
+
+
+  Copyright, HENRY L. AMBLER, 1896.
+        All rights reserved.
+ Entered at Stationers Hall, London.
+
+
+Transcriber's Note:
+
+    Minor typographical errors have been corrected without note. Variant
+    and obsolete spellings, particularly chemical terms, have been
+    retained. The oe ligature is represented by [oe]. Subscript
+    characters are shown _{thus}, for example H_{2}O.
+
+
+
+
+PREFACE.
+
+
+Believing that sufficient and well-deserved prominence was not being
+given to the use of tin foil and its combinations, the author decided to
+present a brief historical résumé of the subject, together with such
+practical information as he possesses, before the profession in order
+that it may have the satisfaction of saving more teeth, since that is
+the pre-eminent function of the modern dentist. One object is to meet
+the demand for information in regard to the properties and uses of tin
+foil; this information has been sought to be given in the simplest form
+consistent with scientific accuracy. The present use of tin is a case of
+the "survival of the fittest," because tin was used for filling teeth
+more than one hundred years ago. There is not a large amount of
+literature upon the subject, and no single text-book has treated the
+matter fully enough to answer the needs of both teacher and pupil. It is
+difficult for the student to collect and harmonize from the many
+different sources just the kind and amount of information required for
+his special use. Perhaps this work will be of assistance to scientific
+students and practical operators in the art of using tin foil, including
+all who wish in compact form an explanation of the facts and principles
+upon which the art is based. A good method to arouse in students an
+interest in the use of tin foil is to have them use it in operative
+technics, which is becoming an effective adjunct in every dental
+college. By this means a great factor will be brought to bear, and the
+result will be that hundreds of graduates every year will begin
+practice better qualified to save teeth than if they had not known
+whatever may be learned about this material. At the University of
+Pennsylvania, Department of Dentistry, session 1896-97, out of the total
+number of fillings made in the clinical department (fractions omitted)
+55 per cent. were gold, 15 per cent. tin, 10 per cent. amalgam. This
+shows that tin has some very strong friends in the persons of Professors
+Darby and Kirk.
+
+The historical sketch of the development of the subject is arranged in
+chronological order, and is given partly to show that some old ideas and
+methods were good, and some obviously incorrect when viewed in the light
+of more recent developments. Part of the history will be new to the
+oldest members of the profession, and the younger ones will certainly
+read it with interest. The work has been brought up to date by
+considering all the properties and methods available. More names, good
+opinions, and dates could have been given, but the writer believes that
+what is herein presented is enough to thoroughly substantiate his own
+opinions, experiments, and practical applications. Some of the
+illustrations have been made especially for this work; the others have
+been obtained through the courtesy of the owners.
+
+"Let not the foggy doctrine of the superiority of gold in all cases act
+on progress as the old medieval superstitions acted on astronomy,
+physiology, zoology. Truth sought after without misgiving, and the
+humblest as well as the highest evidence taken in every case, and acted
+on with skill and discrimination, will crown all with a high average of
+success."
+
+It is hoped that what has been said in this volume will enable those who
+study it to save more teeth, and stimulate them to make improvements on
+the material and methods, doing much better than has been described or
+suggested.
+
+CLEVELAND, OHIO, June, 1897.
+
+
+
+
+    "With soft and yielding lamina, and skill,
+    The practiced dental surgeon learns to fill
+    Each morbid cavity, by caries made,
+    With pliant tin; when thus the parts decayed
+    Are well supplied, corrosion, forced to yield
+    To conquering art the long-contested field,
+    Resigns its victim to the smiles of peace,
+    And all decay and irritation cease."
+                                      (_Solyman Brown._)
+
+The quantity of tin foil used measures the number of teeth saved with
+_metals_ in any country during any historical period.
+
+
+
+
+CONTENTS.
+
+
+                               CHAPTER I.                           PAGE
+ Antiquity of Tin--Alchemistic Name--Medical Use--Where Found--
+   Purity Obtained--Physical Characteristics                           1
+
+                              CHAPTER II.
+ History of the Use of Tin Foil, 1783-1844                             7
+
+
+                              CHAPTER III.
+ History Continued, 1845-1895                                         15
+
+                              CHAPTER IV.
+ Columbian Dental Congress--Opinions on Tin Foil--Reasons for
+   Using--Manufacture in United States--Number and Weight of
+   Foil--Cohesion--Good Qualities of Tin Foil--Temporary Teeth--
+   Thermal Changes--Calcification--Chalky Teeth                       27
+
+                               CHAPTER V.
+ Discoloration of Tin--Decomposition of Food--Sulfids--Oxids--
+   Galvanic, Therapeutic, and Chemical Action                         40
+
+                              CHAPTER VI.
+ White Caries--Gold and Tin as Conductors--Wearing Away of
+   Fillings--Poor Foil--Buccal Cavities--Number of Years
+   Fillings Last--Strips or Tapes for Filling--Number 10 Foil--
+   Form of Cavities--Shields--Matrices--Condensing--Finishing--
+   Cervical Margins--Filling Anterior Teeth--Lining with Gold         49
+
+                              CHAPTER VII.
+ Filling, part Tin, part Gold--Cervical Margin Liable to
+   Caries--Electrolysis--Hand Pressure--Hand Mallet--Tapes and
+   Ropes Compared--Manner of Preparing Foil--Starting the
+   Filling--Cylinders--Mats--Facing and Repairing--Tin
+   Shavings--Dr. Herbst's Method--Fees                                56
+
+                             CHAPTER VIII.
+ Dr. Robinson's Fibrous and Textile Metallic Filling--Tin and
+   Gold combined (Tg), Methods of Preparing and Using--Lining
+   Cavities with Tin--Tin and Amalgam--Plastic Tin--Stannous
+   Gold--Crystal Tin--Filling Root-Canals--Tin and Watts's
+   Sponge Gold--Capping Pulps                                         66
+
+                              CHAPTER IX.
+ Temporary Fillings--Sensitive Cavities--Integrity--Tin with
+   Sponge, Fibrous, and Crystallized Gold--Tin at Cervical
+   Margin--Filling Completed with Gold--Gutta-Percha and Tin--
+   Occlusal Cavities with Tin and Gold--Comparison of Gold with
+   Tin--Wedge-shaped Instruments--Old Method of Using Rolls,
+   Ropes, Tapes, or Strips--Later Method--Filling with Compact
+   and Loose Balls--Cylinder Fillings--Operative Technics             91
+
+
+
+
+CHAPTER I.
+
+
+Moses, who was born 1600 B.C., mentions tin, and history records its use
+500 B.C., but not for filling teeth; much later on, the Ph[oe]nicians
+took it from Cornwall, England, to Tyre and Sidon.
+
+The alchemistic name for tin is Jove, and in the alchemistic
+nomenclature medicinal preparations made from it are called Jovial
+preparations.
+
+Hindoo native doctors give tin salts for urinary affections. Monroe,
+Fothergill, and Richter claim to have expelled worms from the human
+system, by administering tin filings.
+
+Blackie, in "Lays of Highlands and Islands," referring to tin as money,
+says,--
+
+    "And is this all? And have I seen the whole
+    Cathedral, chapel, nunnery, and graves?
+    'Tis scantly worth the tin, upon my soul."
+
+"Tin-penny."--A customary duty formerly paid to the tithingmen in
+England for liberty to dig in the tin-mines.
+
+In 1846, Tin (Stannum, symbol Sn) was found in the United States only at
+Jackson, N. H. Since then it has been found, to a limited extent, in
+West Virginia and adjoining parts of Ohio, North Carolina, Utah, and
+North Dakota. The richest tin mines of the world, however, are in
+Cornwall, England, which have been worked from the time of the
+Ph[oe]nician discovery.
+
+The tin which is found in Malacca and Banca, India, is of great purity,
+and is called "Straits Tin" or "Stream Tin." It occurs in alluvial
+deposits in the form of small rounded grains, which are washed, stamped,
+mixed with slag and scorić, and smelted with charcoal, then run into
+basins, where the upper portion, after being removed, is known as the
+best refined tin. Stream tin is not pure metallic tin, but is the result
+of the disintegration of granitic and other rocks which contain veins of
+tinstone. Banca tin is 99.961 parts tin, 0.019 iron, 0.014 lead in 100
+parts; it is sold in blocks of 40 and 120 pounds, and a bar 0.5 meter
+long, 0.1 broad, 0.005 deep can be bent seventy-four times without being
+broken. Subjected to friction, tin emits a characteristic odor.
+
+Tin in solution is largely used in electro-metallurgy for plating. Pure
+tin may be obtained by dissolving commercial tin in hydrochloric acid,
+by which it is converted into stannous chlorid; after filtering, this
+solution is evaporated to a small bulk, and treated with nitric acid,
+which converts it into stannic oxid, which in turn is thoroughly washed
+and dried, then heated to redness in a crucible with charcoal, producing
+a button of tin which is found at the bottom of the crucible.
+
+Pure tin may be precipitated in quadratic crystals by a slight galvanic
+current excited by immersing a plate of tin in a strong solution of
+stannous chlorid; water is carefully poured in so as not to disturb the
+layer of tin solution; the pure metal will be deposited on the plate of
+tin, at the point of junction of the water and metallic solution.
+
+In the study of tin as a material for filling teeth, we have deemed it
+expedient to consider some of its physical characteristics, in order
+that what follows may be more clearly understood.
+
+Tin possesses a crystallized structure, and can be obtained in
+well-formed crystals of the tetragonal or quadratic system (form right
+square prism), and on account of this crystalline structure, a bar of
+tin when bent emits a creaking sound, termed the "cry of tin;" the purer
+the tin the more marked the cry.
+
+The specific gravity is 7.29; electrical state positive; fusing point
+442° F.; tensile strength per square inch in tons, 2 to 3. Tensile
+strength is the resistance of the fibers or particles of a body to
+separation, so that the amount stated is the weight or power required
+to tear asunder a bar of pure tin having a cross-section of one square
+inch.
+
+Tenacity: Iron is the most tenacious of metals. To pull asunder an iron
+wire 0.787 of a line in diameter requires a weight of 549 lbs. To pull
+asunder a gold wire of the same size, 150 lbs.; tin wire, 34 lbs.; gold
+being thus shown to be more than four times as tenacious as tin.
+(Fractions omitted.)
+
+Malleability: Pure tin may be beaten into leaves one-fortieth of a
+millimeter thick, thus requiring 1020 to make an inch in thickness.
+Miller states that it can be beaten into leaves .008 of a millimeter
+thick, thus requiring 3175 to make an inch in thickness. Richardson says
+that ordinary tin foil is about 0.001 of an inch in thickness.
+
+If the difficulty with which a mass of gold (the most malleable of
+metals) can be hammered or rolled into a thin sheet without being torn,
+be taken as one, then it will be four times as difficult to manipulate
+tin into thin sheets.
+
+Ductility: If the difficulty with which gold (the most ductile of
+metals) can be drawn be taken as one, then it will be seven times as
+difficult to draw tin into a wire. At a temperature of 212° it has
+considerable ductility, and can be drawn into wire.
+
+Among the metals, silver is the best conductor of heat. If the
+conductivity of silver be taken as 100, then the conducting power of
+gold would be 53.2; tin, 14.5; gold being thus shown to be nearly four
+times as good a conductor of heat as tin. Among the metals, silver is
+the best conductor of electricity. If its electrical conductivity be
+taken at 100, then the conducting power of gold would be 77.96; tin,
+12.36; gold being thus shown to be more than six times as good a
+conductor of electricity as tin.
+
+Resistance to air: If exposed to dry, pure air, tin resists any change
+for a _great_ length of time, but if exposed to air containing moisture,
+carbonic acid, etc., its time resistance is reduced, although even then
+it resists corrosion much better than copper or iron.
+
+As to linear expansion, when raised from 32° to 212° F., aluminum
+expands the most of any of the metals. Taking its expansion as 1, that
+of tin would be 3, _i.e._, aluminum expands three times as much as tin.
+(Dixon, "Vade Mecum.")
+
+Solids generally expand equally in all directions, and on cooling return
+to their original shape. Within certain limits, metals expand uniformly
+in direct proportion to the increase in temperature, but the rate of
+expansion varies with different metals; thus, under like conditions, tin
+expands nearly twice (1-3/5) as much as gold, but the _rate_ of
+expansion for gold is nearly twice (1-7/10) that of tin.
+
+The capacity for absorbing heat varies with each metal; that of gold is
+about twice (1-3/4) that of tin.
+
+Tin has a scale hardness of about 4, on a scale of 12 where lead is
+taken as the softest and platinum the hardest. (Dixon, "Vade Mecum.")
+
+Tin has a scale hardness of about 2. (Dr. Miller.)
+
+To fuse a tin wire one centimeter in diameter requires a fusing current
+of electricity of 405.5 amperes. Up to 225° C., the rise in resistance
+to the passage of an electric current is more rapid in tin than in gold.
+In some minerals the current follows the trend of the crystals.
+
+Gold wire coated with tin, and held in the flame of a Bunsen burner,
+will melt like a tin wire. At 1600° to 1800° tin boils and may be
+distilled.
+
+
+
+
+CHAPTER II.
+
+
+The largest and most complete dental library in the world is owned by
+Dr. H. J. McKellops, of St. Louis. Upon his cheerful invitation, the
+writer visited that "Mecca," and through his kindness and assistance a
+complete search was made, which resulted in obtaining a great portion of
+the following historical facts with reference to the use of tin in
+dentistry:
+
+"In 1783 I stopped a considerable decay in a large double under tooth,
+on the outside of the crown or near the gums, with fine tin foil, which
+lasted for a good number of years." ("A Practical and Domestic Treatise
+on Teeth and Gums," by Mr. Sigmond, Bath, England, 1825.)
+
+"Fine tin foil or gold leaf may be injected into a cavity successfully,
+and retained securely for many years." (Joseph Fox, Dover, England,
+1802.)
+
+"The statement has been made several times that tin foil was used in the
+United States for filling teeth as early as 1800, at which time
+dentistry began to be cultivated particularly as a science and art, and
+was beginning to be regarded as of more importance than it formerly had
+been. The writer has not found any record of its use in this country
+earlier than 1809. Tin may often be employed with entire confidence. I
+have seen fillings forty-one years old (made in 1809) and still perfect.
+Several molars had four or five plugs in them, which had been inserted
+at different periods during the last half-century. I prefer strips cut
+from six sheets laid upon each other. If the foil is well connected, the
+cut edges will adhere firmly; if they do not, the foil is not fit for
+use." (Dr. B. T. Whitney, _Dental Register of the West_, 1850.) First
+reference to the fact that tin is adhesive.
+
+"Tin is desirable in all unexposed cavities. It has a stronger affinity
+for acetic, citric, tartaric, malic, lactic, and nitric acids than the
+tooth has: a good material where the secretions are of an acid
+character, it is better that the filling should waste away than the
+tooth. One cavity in my mouth was filled with gold, decay occurred, the
+filling was removed; cavity filled with oxychlorid, which produced pain;
+filling removed; cavity filled with gutta-percha, still experienced
+pain; filling removed; cavity filled with tin, and pain ceased in an
+hour. A tin filling was shown in New York which was sixty years old;
+made in 1811." (Dr. E. A. Bogue, _British Journal of Dental Science_,
+1871.)
+
+"I have lately been removing tin pluggings (the juices of the mouth
+having oxidated and dissolved away the metal, so as to expose the teeth
+to decay) from teeth which I plugged fifteen years ago (1818) for the
+purpose of re-stopping with gold, and have in almost every instance
+found the bone of the tooth at the bottom of the pluggings perfectly
+sound and protected from decay." (J. R. Spooner, Montreal, 1833.)
+
+In 1800 the number of dentists in the United States was about one
+hundred, and many of them were using tin foil for filling teeth.
+
+In 1822 tin was employed by the best dentists, with hardly an exception;
+it grew in favor, especially for large cavities in molars, and for a
+cheaper class of operations than gold, but tin was not generally used
+until 1830. ("History of Dental and Oral Science in America.")
+
+"Lead, tin, and silver corrode and become more injurious than the
+original disease, and will in every case ultimately prove the cause of
+destruction to the tooth, which might have been preserved by proper
+treatment." (Leonard Koecker, 1826, and "New System of Treating the
+Human Teeth," by J. Paterson Clark, London, 1829 and 1830.)
+
+"Tin in situations out of reach of friction in mastication, as between
+two teeth, is like the tooth itself apt to be decomposed by acidity
+unless kept very clean." ("Practical and Familiar Treatise on Teeth and
+Dentism," J. Paterson Clark, London, 1836.) Refer to what the same
+author said in 1829.
+
+"Tin is used as a plugging material." ("The Anatomy, Physiology, and
+Diseases of the Teeth," by Thomas Bell, F.R.S., London, 1829.)
+
+"Silver and tin foil, although bright when first put in a cavity, very
+soon change to a dark hue, resembling the decayed parts of the teeth
+which are of a bluish cast; besides this, they are not sufficiently pure
+to remain in an unchanged state, and frequently they assist in the
+destruction of a tooth instead of retarding it." ("Familiar Treatise on
+the Teeth," by Joseph Harris, London, 1830.)
+
+"Tin is objectionable on account of rapid oxidation and being washed by
+the saliva into the stomach, as it may materially disorder it; the
+filling becomes so reduced that the cavity in which it has been inserted
+will no longer retain it, and acid fruits influence galvanic action."
+("Every Man his Own Dentist," Joseph Scott, London, 1833.)
+
+In 1836 Dr. Diaz, of Jamaica, used tin foil for filling teeth.
+
+"Gold is now preferred, though tin, from its toughness when in the leaf,
+is perhaps the most suitable. Americans are superior to British in
+filling." ("Plain Advice on Care of the Teeth," Dr. A. Cameron, Glasgow,
+1838.)
+
+[Illustration: FIG. 1.]
+
+[Illustration: FIG. 2.]
+
+"Tin foil is used for filling teeth." (S. Spooner, New York, 1838,
+"Guide to Sound Teeth.")
+
+In 1838 Archibald McBride, of Pittsburg, Pa., used tin for filling
+cavities of decay.
+
+The following facts were learned from Dr. Corydon Palmer: E. E. Smith,
+who had been a student of John and William Birkey, in Philadelphia, came
+to Warren, Ohio, in 1839, and among other things made the first gold
+plate in that part of the country. In operating on the anterior teeth,
+he first passed a separating file between them, excavated the cavity,
+and prepared the foil, _tin_ or gold, in tapes which were cut
+transversely, every eighth of an inch, about three-quarters of the way
+across. Fig. 1 shows the size of tape and the manner of cutting. With an
+instrument (Fig. 2) he drew the foil in from the labial surface, using
+such portion of the tape as desired.
+
+The instrument from which the illustration was made was furnished by Dr.
+Palmer, and is shown full size. Instruments for use on posterior teeth
+were short and strong, with as few curves as possible; no right and left
+cutters or pluggers were used, and none of the latter were serrated, but
+had straight, tapering round points, flat on the ends, and of suitable
+size to fill a good portion of the cavity. He used what was termed
+Abbey's chemically pure tin foil, forcing it in hard, layer upon
+layer,--as he expressed it, "smacked it up." In this manner he made tin
+fillings that lasted more than thirty years.
+
+In 1839 Dr. Corydon Palmer filled teeth with tin foil, also lined
+cavities with gold and filled the remainder with tin. In the same year
+he filled crown (occlusal) cavities one-half full with tin and the other
+half with gold, allowing both metals to come to the surface, on the same
+plan that many proximal cavities are now filled. (See Fig. 3, showing
+about one-half of the cavity nearly completed with tin cylinders. The
+same plan was followed when strips, or ropes, were used.)
+
+"I filled cavities about two-thirds full with tin, and finished with
+gold." (S. S. Stringfellow, _American Journal of Dental Science_, 1839.)
+
+"Tin foil is greatly used by some American dentists, but it is not much
+better than lead leaf." ("Surgical, Operative, and Mechanical
+Dentistry," L. Charles De Londe, London, 1840.)
+
+[Illustration: FIG. 3.]
+
+"In 1841 there were about twelve hundred dentists in the United States,
+many of whom were using tin, and there are circumstances under which it
+may be used not only with impunity, but advantage, but it is liable to
+change." (Harris.)
+
+"I put in tin fillings, and at the end of thirty years they were badly
+worn, but there was no decay around the margins." (Dr. Neall, 1843.)
+
+In 1843 Dr. Amos Westcott, of Syracuse, N. Y., filled the base of large
+cavities with tin, completing the operation with gold.
+
+"Tin is used in the form of little balls, or tubes, but folds are
+better; introduce the metal gradually, taking care to pack it so that it
+will bear equally upon all points; the folds superimpose themselves one
+upon the other; thus we obtain a successive stratification much more
+exact and dense, and it is impossible there can be any void." ("Theory
+and Practice of Dental Surgery," J. Lefoulon, Paris, 1844.)
+
+
+
+
+CHAPTER III.
+
+
+"Besides gold, the only material which can be used with any hope of
+permanent success is tin foil. Some dentists call it _silver_, and a
+tooth which cannot be filled with it cannot be filled with anything else
+so as to stop decay and make it last very long. It can be used only in
+the back teeth, as its dark color renders it unsuitable for those in
+front. When the general health is good, and the teeth little predisposed
+to decay, this metal will preserve them as effectually perhaps as gold;
+but where the fluids of the mouth are much disordered it oxidizes
+rapidly, and instead of preserving the teeth rather increases their
+tendency to decay." (Dr. Robert Arthur, Baltimore, 1845, "A Popular
+Treatise on the Diseases of the Teeth.")
+
+The false idea that a patient must have good health, normal oral fluids,
+and teeth little predisposed to decay, or else if filled with tin the
+decay would be hastened, originated with a German or English author, and
+has been handed down in works published since early in 1800. It even
+crept into American text-books as late as 1860, the authors of which now
+disbelieve it.
+
+"Tin undergoes but little change in the mouth, and may be used with
+comparative safety." ("Surgical, Mechanical, and Medical Treatment of
+the Teeth," James Robinson, London, 1846.)
+
+"Tin is soft, and can be easily and compactly introduced, but it is more
+easily acted on by the secretions of the mouth than gold and is less
+durable, but in the mouth of a healthy person _it will last for years_.
+Still, inasmuch as it cannot be depended on in _all_ cases, we are of
+the opinion that it should _never_ be employed." ("The Human Teeth,"
+James Fox, London, 1846.)
+
+The italics are ours. Every metal has a limited sphere of usefulness,
+and it should not be expected that tin will contend single-handed
+against all the complicated conditions which caries presents.
+
+"Of all the cheaper materials, I consider tin the best by far, and
+regard its use fully justifiable in deciduous teeth and in large
+cavities, as it is not every man who can afford the expense of nine
+leaves of gold and four hours of labor by a dentist on a single tooth."
+(Dr. Edward Taylor, _Dental Register of the West_, 1847.)
+
+"I consider tin good for any cavity in a chalky tooth: it will save them
+better than anything else." (Dr. Holmes, 1848.)
+
+"Tin can be used as a temporary filling, or as a matter of economy. It
+may be rendered impervious to air and dampness, but it corrodes in most
+mouths, unless it comes in contact with food in chewing, and then it
+rapidly wears away; it does not become hard by packing or under
+pressure, and that it forms a kind of a union with the tooth is
+ridiculous." (Dr. J. D. White, 1849, _Dental News Letter_.)
+
+"A tin plug will answer a very good purpose in medium and large cavities
+for six years. Much imposition has been practiced with it, and it is not
+made as malleable as it should and can be. An inferior article is
+manufactured which possesses brilliancy and resembles silver. This is
+often passed off for silver foil. No harm comes from this deception
+except the loss of the amount paid above the price for tin; but even
+this inferior tin foil is better than silver." ("The Practical Family
+Dentist," Dewitt C. Warner, New York, 1853.)
+
+"Tin made into leaves is employed as a stopping material; with
+sufficient experience it can be elaborated into the finest lines and
+cracks, and against almost the weakest walls, and teeth are sometimes
+lost with gold that might have been well preserved with tin. I saw an
+effective tin stopping in a tooth of Cramer's, the celebrated musical
+composer, which had been placed there thirty-five years ago by Talma,
+of Paris." ("The Odontalgist," by J. Paterson Clark, London, 1854.)
+
+Refer to what the same author said in 1836.
+
+"Tin is the best substitute for gold, and can often be used in badly
+shaped cavities where gold cannot." (Prof. Harris, 1854.)
+
+"Tin is better than any mixture of metals for filling teeth." (Professor
+Tomes, London, 1859.)
+
+In 1860 a writer said that "such a change may take place in the mouth as
+to destroy tin fillings which had been useful for years, and that tin
+was not entirely reliable in any case; it must not be used in a tooth
+where there is another metal, nor be put in the bottom of a cavity and
+covered with gold, for the tin will yield, and when fluids come in
+contact with the metals, chemical action is induced, and the tin is
+oxidized. Similar fillings in the same mouth may not save the teeth
+equally well. Filling is predicated on the nature of decay, for only on
+correct diagnosis can a proper filling-material be selected."
+
+Reviewing the foregoing statement, we believe that a change may take
+place in the mouth which will destroy gold fillings (or the
+tooth-structure around them) much oftener than those of tin. It is now
+every-day practice to put tin into the same tooth with another metal; if
+the bottom of a cavity is filled with tin properly packed, it will not
+yield when completed with gold, and if the gold is tight, the oral
+fluids cannot come in contact with both metals and produce chemical
+action or oxidation; similar fillings of gold in the same mouth do not
+save the teeth equally well. Should we expect more of tin in this
+respect, or discard it because it is not always better than gold?
+
+In Article V of the "New Departure Creed," Dr. Flagg says, "Skillful and
+scrupulous dentists fill with tin covered with gold, thereby preventing
+decay, pulpitis, death of the pulp, and abscess, and thus save the
+teeth."
+
+In 1862 Mr. Hockley, of London, mentions tin for filling, and the same
+year Dr. Zeitman, of Germany, recommended it as a substitute for gold,
+particularly for poor people.
+
+"Is tin foil poisonous? If not, why are our brethren so reluctant to use
+it? Is it nauseous? If not, why not employ it? Will it not preserve the
+teeth when properly used? Then why not encourage the use of it? Does its
+name signify one too common in the eyes of the people, on account of its
+daily use in the tin shops, or do patients murmur when the fee is
+announced, because it is nothing but tin? Is it not better than amalgam,
+although the patient may believe it less costly? Eleven good plugs,
+twenty-nine years old, in one mouth demonstrates that tin will last as
+long as gold in many cases." (F. A. Brewer, _Dental Cosmos_, 1863.)
+
+"So much tin foil is used for personal and domestic purposes that the
+following is important: Ordinary tin foil by chemical analysis contained
+88.93 per cent. of lead; embossed foil, 76.57 per cent.; tea foil, 88.66
+per cent.; that which was sold for the pure article, 34.62 per cent. Tin
+foil of above kind is made by inclosing an ingot of lead between two
+ingots of tin, and rolling them out into foil, thus having the tin on
+the outside of the lead." (Dr. J. H. Baldock, _Dental Cosmos_, 1867.)
+
+The author used tin foil for filling the teeth of some of his
+fellow-students at the Ohio College of Dental Surgery in 1867.
+
+"Amalgam should never be used in teeth which can be filled with tin, and
+most of them can be." (Dr. H. M. Brooker, Montreal, 1870.)
+
+"I have used tin extensively, and found it more satisfactory than
+amalgam. Dentists ignore tin, because it is easier to use amalgam, less
+trouble. This is not right. If your preceptor has told you that amalgam
+is as good as tin, and he thinks so, let him write an article in its
+defense. Not one dentist in ten who has come into the profession within
+the last ten years knows how to make a tin filling, and only a few of
+the older ones know how to make a _good_ one." (Dr. H. S. Chase,
+_Missouri Dental Journal_, 1870.)
+
+"Among the best operators a more general use of tin would produce
+advantageous results, while among those whose operations in gold are not
+generally successful an almost exclusive use of tin would bring about a
+corresponding quantum of success to themselves and patients, as against
+repeated failures with gold. The same degree of endeavor which lacked
+success with gold, if applied to tin would produce good results and save
+teeth. A golden shower of ducats realized for gold finds enthusiastic
+admirers, but a dull gray shower for tin work is not so admirable, even
+though many of the teeth were no better for the gold as gold, nor so
+well off in the ultimate as with tin." (Dr. E. W. Foster, _Dental
+Cosmos_, 1873.)
+
+In 1873 Dr. Royal Varney said, "I am heartily in favor of tin; it is too
+much neglected by our first-class operators."
+
+"Tin stops the ends of the tubuli and interglobular spaces which are
+formed in the teeth of excessive vascular organization; if more teeth
+were filled with tin, and a smaller number with futile attempts with
+gold, people would be more benefited." (Dr. Castle, _Dental Cosmos_,
+1873.)
+
+"If cavities in teeth out of the mouth are well filled with tin, and put
+into ink for three days, no discoloration of the tooth (when split open)
+can be seen." (W. E. Driscoll, _Dental Cosmos_, 1874.)
+
+"Tin makes an hermetical filling, and resists the disintegrating action
+of the fluids of the mouth. If an operator can preserve teeth for
+fifteen dollars with tin, which would cost fifty dollars with gold,
+ought he not to do so? Upon examination of the cavities from which
+oxidized plugs have been removed, these oxids will be found to have had
+a reflex effect upon the dentin; the walls and floors will be discolored
+and thoroughly indurated, and to a great degree devoid of sensitiveness,
+although they were sensitive when filled. Tin is valuable in case of
+youth, nervousness, impatience, high vitality of dentin, low
+calcification, and low pecuniosity." (Dr. H. Gerhart, _Pennsylvania
+Journal of Dental Science_, 1875.)
+
+"Tin Foil for Filling Teeth." Essay by Dr. H. L. Ambler, read before the
+Ohio State Dental Society. (_Dental Register of the West_, 1875.)
+
+"Some say that if tin is the material the cavity must be filled with,
+that it must be filled entirely with it, but advanced teachings show
+differently." (Dr. D. D. Smith, _Dental Cosmos_, October, 1878.)
+
+"Frail teeth can be saved better with tin than with gold. I never saw a
+devitalized pulp under a tin filling." (Dr. Dixon, _Dental Cosmos_, May,
+1880.)
+
+"Tin may be used as a base for proximate fillings in bicuspids or
+molars, in third molars, in children's permanent molars, in the
+temporary teeth, and in any cavity where the filling is not
+conspicuous." (Dr. A. W. Harlan, _Independent Practitioner_, 1884.)
+
+"Tin in blocks, mats, and tapes is used like non-cohesive gold foil, but
+absence of cohesion prevents the pieces from keeping their place as well
+as the gold." ("American System of Dentistry," 1887.)
+
+This is virtually saying that there is cohesion of non-cohesive gold,
+and that for this reason it keeps its place better than tin. It has
+always been supposed that there was no cohesion of layers of
+non-cohesive gold, and as the tin is used on the non-cohesive plan,
+therefore one keeps its place as well as the other. We claim that
+generally in starting a filling, tin will keep its place better than
+cohesive or non-cohesive gold, because it combines some of the
+cohesiveness of the former with the adaptability of the latter.
+
+"Tin will save teeth in many cases as well or better than gold. Put a
+mat of tin at the cervical wall of proximate cavities in molars and
+bicuspids, and it makes a good filling which has a therapeutic effect on
+tooth-structure that prevents the recurrence of caries, probably because
+the infiltration of tin oxid into the tubuli is destructive to animal
+life. Where the filling is not exposed to mechanical force, there is no
+material under heavens which will preserve the teeth better." (Dr.
+Beach, _Dental Cosmos_, 1889.)
+
+"I extracted a tooth in which I found a cavity of decay which had
+extended toward a tin filling, but stopped before reaching it; on
+examining the tooth-structure between the new cavity and the tin
+filling, it was found to be very hard, indicating apparently that there
+had been some action produced by the presence of the tin." (Dr. G.
+White, _Dental Cosmos_, 1889.)
+
+"Pure tin in form of foil is used as a filling and also in connection
+with non-cohesive gold." (Mitchell's "Dental Chemistry," 1890.)
+
+"Tin ranks next to gold as a filling-material." (Essig's "Dental
+Metallurgy," 1893.)
+
+"Tin is good for children's teeth, when gold or amalgam is not
+indicated. It can be used in cavities which are so sensitive to thermal
+changes as to render the use of gold or amalgam unwise, but it can only
+be used in cavities with continuous walls, and should be introduced in
+the form of cylinders or ropes, with wedge-shaped pluggers having sharp
+deep serrations, thus depending upon the wedging or interdigitating
+process to hold the filling in the cavity." ("Operative Technics," Prof.
+T. E. Weeks, 1895.)
+
+"Tin for filling teeth has been almost superseded by amalgam, although
+among the older practitioners (those who understand how to manipulate
+it) tin is considered one of the best, if not the very best metal known
+for preserving the teeth from caries. In consequence of its lack of the
+cohesive property, it is introduced and retained in a cavity upon the
+wedging principle, the last piece serving as a keystone or anchor to the
+whole filling. Each piece should fill a portion of the cavity from the
+bottom to the top, with sufficient tin protruding from the cavity to
+serve for thorough condensation of the surface, and the last piece
+inserted should have a retaining cavity to hold it firmly in place. The
+foil is prepared by folding a whole or half-sheet and twisting it into a
+rope, which is then cut into suitable lengths for the cavity to be
+filled." (Frank Abbott, "Dental Pathology and Practice," 1896.)
+
+"Forty-three years ago, for a young lady fourteen years of age, I
+filled with non-cohesive gold all the teeth worth filling with this
+metal; the rest I filled with tin. Three years after that there was not
+a perfect gold filling among the whole number, and yet the tin fillings
+were just as good as when made. The explanation as to why the tin
+fillings lasted so much longer than the gold ones was, that there must
+have been something in the tin that had an affinity for the teeth and
+the elements that formed the dentin, by which some compound was formed,
+or else it must have been in the adaptation." (Dr. H. Gerhart, _Dental
+Cosmos_, January, 1897.)
+
+
+
+
+CHAPTER IV.
+
+
+At the World's Columbian Dental Congress, held in Chicago, August, 1893,
+the author presented an essay on "Tin Foil for Filling Teeth."
+
+During the discussion of the subject, the following opinions were
+elicited:
+
+Dr. E. T. Darby: "I have always said that tin was one of the best
+filling-materials we have, and believe more teeth could be saved with it
+than with gold. I have restored a whole crown with tin, in order to show
+its cohesive properties; the essayist has paid a very high and worthy
+tribute to tin."
+
+Dr. R. R. Freeman: "I have used tin foil for twenty-five years, and know
+that it has therapeutic properties, and is one of the best
+filling-materials, not excepting gold."
+
+Madam Tiburtius-Hirschfield: "I heartily indorse the use of tin, and
+have tested its cohesive properties by building up crowns."
+
+Dr. A. H. Brockway: "I am a strong believer in the use of tin, on
+account of its adaptability, and the facility with which saving fillings
+can be made with it."
+
+Dr. Gordon White: "After having used tin for nine years, I claim that
+it is the best filling-material that has been given to our profession."
+
+Dr. C. S. Stockton: "Tin is one of the best materials for saving teeth,
+and we should use it more than we do."
+
+Dr. James Truman: "I use tin strictly upon the cohesive principle, and
+would place it in all teeth except the anterior ones, but would not
+hesitate to fill these when of a chalky character."
+
+Dr. Corydon Palmer: "For fifty-four years I have been a firm advocate of
+the use of tin, and I have a filling in one of my teeth which is forty
+years old."
+
+Dr. William Jarvie: "I rarely fill a cavity with gold for children under
+twelve years of age that I want to keep permanently, but use tin, and in
+five or ten years, more or less, it wears out. Still, it can easily be
+renewed, or if all the tin is removed we find the dentin hard and firm.
+The dentist is not always doing the best for his patients if he does not
+practice in this way."
+
+Dr. C. E. Francis: "I have proved positively that tin foil in good
+condition is cohesive, and my views have been corroborated by dentists
+and chemists."
+
+Dr. James E. Garretson: "Tin foil is cohesive, and can be used the same
+as gold foil, and to an extent answers the same purpose."
+
+Dr. C. R. Butler: "Tin is cohesive and makes a first-class saving
+filling."
+
+Dr. W. C. Barrett: "Tin is as cohesive as gold, and if everything was
+blotted out of existence with which teeth could be filled, except tin,
+more teeth would be saved."
+
+Dr. L. D. Shepard: "Tin possesses some antiseptic properties for the
+preservation of teeth that gold does not."
+
+Dr. W. D. Miller: "I use tin foil in cylinders, strips, and ropes, on
+the non-cohesive plan, but admit that it possesses a slight degree of
+cohesiveness, and when necessary can be built up like cohesive gold by
+using deeply serrated pluggers."
+
+Dr. Benjamin Lord says, "It is said that we know the world, or learn the
+world, by comparison. If we compare tin foil with gold foil, we find
+that the tin, being softer, works more kindly, and can be more readily
+and with more certainty adapted to the walls, the inequalities, and the
+corners of the cavities.
+
+"We find also that tin welds--mechanically, of course--more surely than
+soft gold, owing to its greater softness; the folds can be interlaced or
+forced into each other, and united with more certainty, and with so
+much security that, after the packing and condensing are finished, the
+mass may be cut like molten metal.
+
+"I contend moreover that for contouring the filling or restoring the
+natural shape of the teeth, where there are three walls remaining to the
+cavity, tin is fully equal to gold, and in some respects even superior;
+as tin can be secured, where there is very little to hold or retain the
+filling, better than gold, owing to the ease and greater certainty of
+its adaptation to the retaining points or edges of the cavity.
+
+"It will be said, however, that tin fillings will wear away. The
+surfaces that are exposed to mastication undoubtedly will wear in time;
+but the filling does not become leaky if it has been properly packed and
+condensed, nor will the margins of the cavity be attacked by further
+decay on that account.
+
+"Altogether, I believe that we can make more perfect fillings with tin
+than we can with gold, taking all classes of cavities; but it must not
+be understood that it is proposed that tin should ever take the place of
+gold where the circumstances and conditions indicate that the latter
+should be used. Of course, the virtue is not in the gold or the tin, but
+in the mechanical perfection of the operation, and tin having more
+plasticity than gold, that perfection can be secured with more ease and
+certainty.
+
+"If we compare tin with amalgam, we must certainly decide in favor of
+the former and give it preference; as if it is packed and condensed as
+perfectly as may be, we know just what such fillings will do every time.
+We know that there will be no changes or leakage of the fillings at the
+margins; whereas, with amalgam, the rule is shrinkage of the mass, and
+consequently the admission of moisture around the filling, the result
+being further decay. It is not contended that this is always the result
+with amalgam, but it is the general rule; yet we must use amalgam, as
+there are not a few cases where it is the best that we can do; but it is
+to be hoped, and I think it may be said, that as manipulative skill
+advances, amalgam will be less and less used. For so-called temporary
+work, very often I prefer tin to gutta-percha, as it makes a much more
+reliable edge and lasts longer, even when placed and packed without
+great care."--_N. Y. Odon. Society Proceedings_, page 51, 1894.
+
+One of the main reasons which induced the writer to begin the use of tin
+foil (_Stannum Foliatum_) for filling teeth, in 1867, was the fact that
+amalgam filling failures were being presented daily. Believing that tin
+could do no worse, but probably would do better, we banished amalgam
+from the office for the succeeding seven years, using in the place of
+it tin, oxychlorid, and gutta-percha. Since that time we have seen no
+good reason for abandoning the use of tin, as time has proved it worthy
+of great confidence. There is no better dental litmus to distinguish the
+conservative from the progressive dentist.
+
+If we take a retrospective view and consider what tin foil was thirty
+years ago, we do not wonder that so many operators failed to make tight,
+good-wearing fillings. As it came from the manufacturer it looked fairly
+bright, but after being exposed to the air for a short time it assumed a
+light brassy color, and lost what small amount of integrity it
+originally possessed. This tin was not properly refined before beating,
+or something was put on the foil while beating, so that it did not have
+the clean, bright surface and cohesive quality which our best foil now
+has. No. 4 was commonly used, but it would cut and crumble in the most
+provoking manner. Fillings were made by using mats, cylinders, tapes,
+and ropes, with hand-pressure, on the plan for manipulating non-cohesive
+gold foil, but it was difficult to insert a respectable approximal
+filling.
+
+From the best information obtainable, the writer believes that Marcus
+Bull (the predecessor of Abbey) was the first to manufacture and sell
+tin foil in the United States, as he began the manufacture of gold foil
+at Hartford in 1812.
+
+Several years ago a radical change came about in the preparation of tin
+foil, for which the manufacturer should have his share of the credit,
+even if the dentist did ask for something better, for the quality
+depends largely upon the kind and condition of the tin used and on the
+method of manufacture.
+
+For making tin foil for filling teeth, the purest Banca tin that can be
+obtained is used. The tin is melted in a crucible under a cover of
+powdered charcoal. It is then cast into a bar and rolled to the desired
+thickness, so that if No. 6 foil is to be made, a piece one and one-half
+(1-1/2) inches square would weigh nine grains. This ribbon is then cut
+into lengths of about four feet, and spread on a smooth board slanted,
+so that the end rests in a vat of clean water.
+
+Then apply to the exposed surface of the ribbon diluted muriatic acid,
+and immediately wash with a strong solution of ammonia. Turn the ribbon
+and treat the other side in the same way. It is then washed and rubbed
+dry. The object of using the acid is to remove stains and whiten the
+tin, and the ammonia is used to neutralize the effect of the acid.
+
+The strips are then cut into pieces one and a half inch square, filled
+into a cutch and beaten to about three inches square. It is then removed
+from the cutch and filled into a mold, and further beaten to the desired
+size. When the ragged edges are trimmed off, the foil is ready for
+booking.
+
+It takes skill and experience to beat tin foil, for it is not nearly as
+malleable as gold; up to No. 20 it is usually beaten, but higher numbers
+are prepared by rolling. In each case the process is similar to that
+employed in preparing gold foil. The number on the book is supposed to
+indicate the weight or thickness of the leaf. On the lower numbers the
+paper of the book leaves its impression.
+
+On weighing sheets of tin foil from different manufacturers a remarkable
+discrepancy was found between the number on the book and the number of
+grains in a sheet, viz: Nos. 3, 4, 5, weighed 7 gr. each; No. 6, 9 gr.;
+No. 8, from 9 to 18 gr.; No. 10, from 14 to 15 gr.; No. 20, 18 gr. In
+some instances the sheets in the same book varied three grains. We
+submit that it would be largely to the advantage of both manufacturer
+and dentist to have the number and the grains correspond. No dentist
+wishes to purchase No. 8 and find that he has No. 18; no one could sell
+gold foil under like circumstances. Of the different makes tested,
+White's came the nearest to being correct. The extra tough foil which
+can now be obtained is chemically pure, and with it we can begin at the
+base of any cavity, and with mallet or hand force produce a filling
+which will be one compact mass, so that it can be cut and filed; yet in
+finishing, it will not bear so severe treatment as cohesive gold. Always
+handle tin foil with clean pliers, never with the fingers; and prepare
+only what is needed for each case, keeping the remainder in the book
+placed in the envelope in which it is sold, otherwise extraneous matter
+collects upon it, and it will oxidize _slightly_ when exposed to the air
+for a _great_ length of time.
+
+Before using tin foil, a few prefer to thoroughly crumple it in the
+hands or napkin, under the impression that they thus make it more
+pliable and easier to manipulate.
+
+A piece of blue litmus paper moistened and moved over a sheet of tin
+foil will occasionally give an acid reaction, probably owing to the acid
+with which it is cleaned before beating not having been thoroughly
+removed. Foil held under the surface of distilled water and boiled for
+five minutes, then left until the water is cold, removed and dried,
+shows it has been annealed, which makes it work easily, but not as hard
+a filling can be made from it as before boiling.
+
+In selecting and using this material for filling, we are able fully to
+protect the cavity; and if we understand the material, and how to
+manipulate it, we will surely succeed. This statement demands serious
+attention, and appeals to every one who is anxious to practice for the
+best interests of his patients; then let us make a thorough study of the
+merits of the method and material.
+
+Until recently, the term cohesion had but one special meaning to
+dentists, and that as applied to gold for filling teeth; being
+understood as the property by which layers of this metal could be united
+without force so as to be inseparable. The writer claims that good tin
+foil in proper condition is cohesive when force is applied, and can be
+used for filling teeth in the same manner in which cohesive gold foil is
+used. This claim has been confirmed by several dentists, as noted in
+another part of this volume.
+
+Cohesion is the power to resist separation, and it acts at insensible
+distances. The integral particles of a body are held together by
+cohesion, the constituent parts are united by affinity.
+
+The attraction between atoms of pure tin represents cohesion. Marble is
+composed of lime and carbonic acid, which are united and held together
+by affinity.
+
+The condition which obtains in the tin may be called cohesion, adhesion,
+welding, or interdigitation, but the fact remains that layers of tin
+foil can be driven together into a solid mass, making a tight filling
+with less malleting than is required for gold; if it is overmalleted,
+the receiving surface is injured.
+
+On account of its pliability it is easily adapted to the walls and
+margins, and a perfect fit is made, thus preventing capillary action and
+preventing further caries. Of all the metals used for filling it is the
+best tooth-preserver and the most compatible with tooth-substance, and
+the facility with which a saving filling can be made largely commends
+it.
+
+Tin has great possibilities, and has already gained a high position as a
+filling-material. Upon the knowledge we possess of the possibilities and
+limitations of tin as a filling-material, and our ability to apply that
+knowledge, will largely depend our success in preserving teeth.
+
+It is a good material for filling many cavities in the temporary teeth,
+and children will bear having it used, because it can be placed quickly,
+and but little force is required to condense one or two layers of No. 10
+foil. The dentin in young teeth has a large proportion of organic
+material, for which reason, if caries takes place, many believe it is
+hastened by thermal changes. Gold fillings in such teeth might prevent
+complete calcification, on account of the gold being so good a
+conductor; but if tin is used, there is much more probability of
+calcification taking place, because of its low conductivity and its
+therapeutic influence. It does not change its shape after being packed
+into a cavity. Under tin, teeth are calcified and saved by the deposit
+of lime-salts from the contents of the dentinal tubuli. This is termed
+progressive calcification.
+
+Like other organs of the human body, the teeth are more or less subject
+to constitutional change. The condition in which we find tooth-structure
+which needs repairing or restoring should be a sure indicator to us in
+choosing a filling-material. Up to the age of fourteen, and sometimes
+later, we find many teeth which are quite chalky. In some mouths also,
+at this period, the fluids are in such a condition that oxychlorid and
+oxyphosphate do not last long; for some reason amalgam soon fails, while
+gutta-percha is quickly worn out on an occlusal surface. In all such
+cases we recommend tin, even in the anterior teeth, for as the patient
+advances in years the tooth-structure usually becomes more dense, so
+that, if desirable, the fillings can be removed, and good saving
+operations can be made with gold. By treating cases in this manner very
+little, if any, tooth-structure is lost.
+
+The teeth of the inhabitants of Mexico and Guatemala are characteristic
+of their nervous and nervo-lymphatic temperaments; children ten years of
+age often have twenty-eight permanent teeth, and they are generally soft
+or chalky, but our dentists there report good success in saving them
+with tin.
+
+In filling this class of teeth, we should be very careful not to use
+force enough to injure the cavity-margin, for if this occurs, a leaky
+filling will probably be the result. Still, we have seen some cases
+where _slight_ imperfections at the margin, which occurred at the time
+of the filling or afterward, did no harm, because the deposit of tin
+oxid filled up the ends of the tubuli, thus preventing caries. We
+believe that this bar to the progress of caries is set up more
+frequently when tin is used than with any other metal under like
+conditions.
+
+
+
+
+CHAPTER V.
+
+
+In some mouths tin does not discolor, but retains a clean, unpolished
+tin color, yet when there is a sesquioxid of the metal formed, fillings
+present a grayish appearance. In the same mouth some fillings will be
+discolored, while others are not. As a general rule, proximal fillings
+are most liable to show discoloration. Perhaps one reason is that on
+occlusal and buccal surfaces they are subject to more friction from
+mastication, movements of the cheeks, and the use of the brush.
+
+We have seen a large number of fillings which were not blackened, yet
+were saving the teeth perfectly, thus proving to a certainty that
+blackening of tin in the tooth-cavity is not absolutely essential in
+order to obtain its salvatory effects as a filling-material.
+
+Where there is considerable decomposition of food which produces
+sulfuretted hydrogen, the sulfid of tin may be formed on and around the
+fillings; it is of a yellowish or brownish color, and as an antiseptic
+is in such cases desirable. To offset the discoloration, we find that
+the sulfid is insoluble, and fills the ends of the tubuli, thus lending
+its aid in preventing further caries. A sulfid is a combination of
+sulfur with a metal or other body. A tin solution acted on by
+sulfuretted hydrogen (H_{2}S) produces a dark-brown precipitate (SnS),
+stannous salt, which is soluble in ammonium sulfid (NH_{4})_{2}S_{2};
+this being precipitated, gives (SnS_{2}) stannic salt, which is yellow.
+Brown precipitates are formed by both hydrogen sulfid and ammonium
+sulfid, in stannous solutions. Yellow precipitates are formed by
+hydrogen sulfid and ammonium sulfid in stannic solutions. The yellow
+shade is very seldom seen on tin fillings; the dark brown is more
+common.
+
+An oxid is a combination of oxygen with a metal or base destitute of an
+acid. In oxidation the oxygen that enters into combination is not
+sufficient to form an acid. The protoxid of tin (SnO) is black, and can
+be obtained from chlorid of tin, or by _long_ exposure of tin to the
+atmosphere. The oxygen in the saliva helps to blacken the tin, and the
+metallic oxid penetrates the dentin more or less, acting as a
+protection, because it is insoluble. Oxygen is the only element which
+forms compounds with all others, and is the type of electro-negative
+bodies; it combines with all metals, therefore with tin, and in many
+cases only the metal is discolored, and not the tooth. Steam boilers are
+made tight by oxidation.
+
+Where there is complete oxidation, the tooth is blackened to but a very
+slight depth, and the oxid fills the ends of the tubuli, thus affording
+an additional barrier to the entrance of caries. The filling itself will
+prevent caries, but oxidation acts as an assistant.
+
+"In the mouth, a suboxid is more likely to be formed than a protoxid,
+but both are black; sulfur and oxygen are capable of acting on tin under
+favorable circumstances, such as warmth, moisture, full contact,
+condensation of elements, and their nascent conditions; the first three
+are always present in the mouth. The protosulfuret of tin is black."
+(Dr. George Watt.) Others give the color as bluish-gray, nearly black.
+
+Experiments show that slight galvanic currents exist between fillings of
+dissimilar metals in the mouth, and practical experience demonstrates
+that these currents occasionally produce serious results.
+
+Direct galvanic currents do not decompose normal teeth by true
+electrolysis, but acids resulting from decomposition of food and fluids
+react upon the lime constituents of the teeth and promote secondary
+caries.
+
+When two metals are so situated in the mouth that the mucous membrane
+forms a connecting conductor and the fluids are capable of acting on
+one metal, galvanic action is established sufficient to decompose any of
+the binary compounds contained in these fluids; the liberated nitrogen
+and hydrogen form ammonia, which being exposed to the action of oxygen
+is decomposed and nitric oxid formed, resulting in nitric acid. We also
+have in the mouth air, moisture, and decomposing nitrogenous food to
+assist in the production of nitric acid.
+
+"Galvanic action is more likely to develop hydrochloric acid, for the
+chlorids of sodium and potassium are present in the normal saliva and
+mucus, and when decomposed their chlorin unites with the hydrogen
+derived from the water of the saliva." (Dr. George Watt.)
+
+The fact should also be noted that both nitric and hydrochloric acids
+are administered as medicine, and often assist in producing decay.
+
+When there is a battery formed in a mouth containing tin fillings and
+gold fillings, and the fluids of the mouth are the exciting media, tin
+will be the positive element and gold the negative element; thus when
+they form the voltaic pair, the tin becomes coated or oxidized and the
+current practically ceases.
+
+There is more or less therapeutical and chemical action in cavities
+filled with tin, and its compatibility and prophylactic behavior as a
+filling-material depends partly upon the chemical action which occurs.
+
+Some dentists fill sensitive cavities with tin, in order to secure
+gentle galvanic action, which they believe to be therapeutic,
+solidifying the tooth-structure.
+
+"Tin possesses antiseptic properties which do not pertain to gold for
+arresting decay in frail teeth; it not only arrests caries mechanically,
+but in chalky (imperfect) structure acts as an antacid element in
+arresting the galvanic current set up between the tooth-structure and
+filling-material." (Dr. S. B. Palmer.) If the metal is acted on, the
+tooth is comparatively safe; if the reverse, it is more or less
+destroyed. The galvanic taste can be produced by placing a piece of
+silver on the tongue and a steel pen or piece of zinc under it; then
+bring the edges of the two pieces together for a short time, rinse the
+saliva around in the mouth, and the peculiar flavor will be detected.
+
+"In 1820 attention was called to the injurious effects of the galvanic
+current on the teeth, and dentists were advised never to use tin and
+amalgam in the same mouth.
+
+"A constant galvanic action is kept up in the mouth when more than one
+kind of metal is used in filling teeth, and galvanism is often the
+cause of extensive injury to the teeth. The most remarkable case I ever
+saw was that of a lady for whom I filled several teeth with tin. After a
+time decay took place around some of the fillings. I removed them and
+began to refill, but there was so much pain I could not proceed. I found
+that by holding a steel plugger an inch from the tooth I could give her
+a violent galvanic shock. I observed that the exhalation of the breath
+increased the evolution of galvanism." (Dr. L. Mackall, _American
+Journal of Dental Science_, 1839.)
+
+"When a faulty tooth in the upper jaw had been stopped from its side
+with tin, the interstice between it and the adjoining tooth being quite
+inconsiderable, while the upper surface of a tooth not immediately
+beneath it in the lower jaw was stopped with the same metal, I have
+known a galvanic shock regularly communicated from one tooth to the
+other when by the movement of jaws or cheeks they were brought near
+together." (Dr. E. Parmly, _American Journal of Dental Science_, 1839.)
+
+"An interesting debate here sprung up on the action where two metals are
+used in one filling, such as gold and tin, the saliva acting as a
+medium, and where the baser metal is oxidized by exhalents and by
+imbibition through the bony tooth-structure." (Pennsylvania Society of
+Dental Surgeons, 1848.)
+
+"A patient came to me and complained of pain in the teeth. Upon
+examination I found an amalgam filling next to one of tin. With a file I
+made a V-shaped separation, when they experienced immediate relief from
+pain." (Dr. Nevill, _American Journal of Dental Science_, 1867.)
+
+In regard to the decay of teeth being dependent on galvanic action
+present in the mouth, Dr. Chase, in 1880, claimed that a tooth filled
+with gold would necessarily become carious again at the margin of the
+cavity, wherever the acid secretions constantly bathe the filling and
+tooth-substance. A tooth filled with amalgam succumbs to this
+electro-chemical process less rapidly, while one filled with tin still
+longer escapes destruction. The comparative rapidity with which teeth
+filled with gold, amalgam, or tin, are destroyed is expressed by the
+numbers 100, 67, 50. He prepared pieces of ivory of equal shape and
+size, bored a hole in each, and filled them. After they had been exposed
+to the action of an acid for one week, they had decreased in
+weight,--viz, piece filled with gold, 0.06; amalgam, 0.04; tin, 0.03.
+
+"With tin and gold, some have the superstition that the electricity
+attendant upon such a filling will in some way be injurious to the
+tooth; it matters not which is on the outside, when rolled and used as
+non-cohesive cylinders each appears. We say that neither experimentally,
+theoretically, nor practically can any good or bad result be expected
+from the electrical action of a tin-gold filling on tooth-bone, and
+neither will the pulp be disturbed." (Dr. W. D. Miller, _Independent
+Practitioner_, August, 1884.)
+
+"When the bottom of a cavity is filled with tin which is tightly
+(completely) covered with gold, there is _practically_ no galvanic
+action and there is no current generated by contact of tin and
+gold,--_i.e._, no current leaves the filling to affect the dentin. That
+portion of tin which forms the base is more positive than a full tin
+filling would be. The effect is to cause the surface exposed to dentin
+to oxidize more than tin would do alone; in that there is a benefit. In
+very porous dentin there is enough moisture to oxidize the tin, by
+reason of the current set up by the gold." (Dr. S. B. Palmer.)
+
+Electricity generated by heat is called thermo-electricity. If a cavity
+with continuous walls is half filled with tin and completed with gold,
+or half filled with silver and completed with gold, and the junctions of
+the metal are at 20-1/2° C. and 19-1/2° C., if the electrical action
+between the tin and gold be 1.1, the action between the silver and gold
+will be 1.8, thus showing the action in silver and gold to be nearly
+two-thirds more than in the tin and gold, a deduction which favors the
+tin and gold.
+
+Rubbing two different substances together is a common method of
+producing an electric charge. Is there not more electricity generated
+during mastication on metal fillings than when the jaws are at rest?
+Friction brings into close contact numerous particles of two bodies, and
+perhaps the electrical action going on more or less all the time through
+gold fillings (especially when other metals are in the mouth) accounts
+for a powdered condition of the dentin which is sometimes found under
+cohesive gold fillings, but not under tin.
+
+
+
+
+CHAPTER VI.
+
+
+White caries, the most formidable variety known, may be produced by
+nitric acid, and in these cases all the components of the tooth are
+acted upon and disintegrated as far as the action extends. In proximal
+cavities attacked by this kind of caries, separate freely on the lingual
+side, and fill with tin. When such fillings have been removed the dentin
+has been found somewhat discolored and greatly solidified as compared to
+its former condition; this solidification or calcification is more
+frequent under tin than gold, which is partly due to the tin as a poor
+conductor of heat. Nature will not restore the lost part, but will do
+the next best thing--solidify the dentin. In some cases, under tin, the
+pulp gradually recedes, and the pulp-cavity is obliterated by secondary
+dentin. In other cases the pulps had partly calcified under tin. It has
+been known for years that tin would be tolerated in large cavities very
+near the pulp without causing any trouble, and one reason for this is
+its low conducting power. Attention is called to the fact that gold is
+nearly four times as good a conductor of heat as tin, and more than six
+times as good a conductor of electricity. Where tin fillings are
+subject to a large amount of attrition, they wear away sooner or later,
+but this is not such a great detriment, for they can easily be repaired
+or replaced, and owing to the concave form produced by wear the patient
+is liable to know when a large amount has been worn away. That portion
+against the wall of the cavity is the last removed by wear, so that
+further caries is prevented so long as there is any reasonable amount of
+tin left. If at this time the tooth has become sufficiently solidified,
+proper anchorage can be cut in the tin or tooth, one or both, as
+judgment dictates, and the filling completed with gold. A tin filling,
+confined by four rather frail walls, may condense upon itself, but it is
+so soft and adaptable that the force which condenses it continually
+secures the readaptation at the margin; thus there will be no leakage or
+caries for years. Owing to its softness and pliability, it may be driven
+into or onto the tubuli to completely close them from outside moisture,
+and with a hand burnisher the tin can be made to take such a hold on
+dry, rough tubuli that a cutting instrument is necessary to remove all
+traces of it.
+
+Tin foil has been found in the market that under a magnifying glass
+showed innumerable tiny black specks, which, upon being touched with an
+instrument, crumbled away, leaving a hole through the foil. More than
+likely, some of the failures can be attributed to the use of such foil.
+Good tough foil, well condensed by hand or mallet force, stays against
+the walls of a cavity and makes a tight filling, and ought to be called
+as near perfect as any filling, because it preserves the tooth, and
+gives a surface which will wear from five to twenty years, depending
+upon the size and location of the cavity and tooth-structure. Buccal
+cavities in the first permanent molars, and lingual cavities in the
+superior incisors, filled for children from six to eight years of age,
+are still in good condition after a period of twenty years. Perhaps the
+limit is reached in the following cases, all in the mouths of
+_dentists_: One filling forty years old; one forty-two; four on the
+occlusal surface, fifty; in the latter case gold had been used in other
+cavities and had failed several times. Lingual cavities in molars and
+bicuspids can be perfectly preserved with tin. Tapes of No. 10 foil,
+from one to three thicknesses, can be welded together and will cohere as
+well or better than semi-cohesive gold foil, and it can be manipulated
+more rapidly; therefore, if desirable, any degree of contour can be
+produced, but the contour will not have the hardness or strength of
+gold, so in many cases it would not be practicable to make extensive
+contours with tin, owing to its physical characteristics.
+
+No. 10 will answer for all cases, and it is not as liable to be torn or
+cut by the plugger as a lower number, but one need not be restricted to
+it, as good fillings can be made with Nos. 4, 6, or 8. More teeth can be
+saved with tin than with any other metal or metals, and the average
+dentist will do better with tin than with gold. It is invaluable when
+the patient is limited for time or means, and also for filling the first
+permanent molars, where we so often find poor calcification of
+tooth-structure. In cases of orthodontia, where caries has attacked a
+large number of teeth, it is well to fill with tin, and await further
+developments as to irregularity and caries.
+
+If cavities are of a good general retaining form, that will be
+sufficient to hold the filling in place; but if not, then cut slight
+opposing angles, grooves, or pits. Cavities are generally prepared the
+same as for gold, except where there is a great deal of force brought
+upon the filling; then the grooves or pits may be a little larger;
+still, many cavities can be well filled with less excavating than
+required for gold, and proximal cavities in bicuspids and molars, where
+there is sufficient space, can be filled without removing the occlusal
+surface, and here especially should the cavities be cut square into the
+teeth, so as not to leave a feather edge of tin when the filling is
+finished, as that would invite further caries and prove an obstruction
+to cleansing the filling with floss.
+
+In proximal cavities involving the occlusal surface, cut the cervical
+portion down to a strong square base, with a slight pit, undercut, or
+angle, at the buccal and lingual corners; where there is sufficient
+material, a slight groove across the base, far enough from the margin so
+that it will not be broken out, can be made in place of the pit,
+undercut, or angle; then cut a groove in the buccal and lingual side
+(one or both, according to the amount of material there is to work
+upon), extending from the base to the occlusal surface; in most of these
+cases the occlusal grooves or pits would have to be excavated on account
+of caries; thus there would be additional opportunity for anchorage. In
+place of the grooves the cavity may be of the dovetail form. In nearly
+all proximal cavities in bicuspids and molars, some form of metal
+shield, or matrix, is of great advantage, as they prevent the tin from
+crushing or sliding out. By driving the tin firmly against the metal, a
+well-condensed surface is secured; and as the metal yields a little, we
+can with a bevel or thin plugger force the tin slightly between the
+metal and the margin of the cavity, thus making sure of a tight filling,
+with plenty of material to finish well. After removing the metal,
+condense with thin burnishers and complete the finish the same as for
+gold. Where no shield or matrix is used, or where it is used and removed
+before completing the filling, it is often desirable to trim the
+cervical border, for in either case there is more light and room to work
+when only a portion of the cavity has been filled. Tin cuts so much
+easier than gold, it is more readily trimmed down level with all
+cervical margins.
+
+Be sure that all margins are made perfect as the work progresses, and if
+the cavity is deep and a wide shield shuts out the light, then use a
+narrow one, which can be moved toward the occlusal surface from time to
+time.
+
+In filling the anterior teeth when the labial wall is gone, and the
+lingual wall intact or nearly so, use a piece of thin metal
+three-quarters of an inch long and wide enough to cover the cavity in
+the tooth to be filled, insert it between the teeth, and bend the
+lingual end over the cavity; the labial end is bent out of the way over
+the labial surface of the adjoining tooth, as shown in Fig. 4. When the
+labial wall is intact or nearly so, access to the cavity should be
+obtained from the lingual side, and in this case the bending of the
+shield would be reversed, as shown in Fig. 5. The shield is not
+absolutely essential, but it helps support the tin, and also keeps a
+separation.
+
+[Illustration: FIG. 4.]
+
+[Illustration: FIG. 5.]
+
+It is preferable to save the labial wall and line it with (say) five
+layers of No. 4 semi-cohesive gold folded into a mat and extended to the
+outer edge of the cavity; this gives the tooth a lighter shade, and
+bicuspids or molars can be filled in the same manner. Cases are on
+record where incisors with translucent labial walls, filled by this
+method, have lasted from twenty-three to thirty-seven years.
+
+
+
+
+CHAPTER VII.
+
+
+For the last ten years the writer has been using tin at the cervical
+margin of proximal cavities in bicuspids and molars, especially in deep
+cavities (now an accepted practice), and he finds that it prevents
+further caries oftener than any other metal or combination of metals he
+has ever seen used. In filling such cavities, adjust the rubber, and use
+a shield or matrix of such form as to just pass beyond the cervical
+margin; this will generally push the rubber out of the cavity, but if it
+does not, then form a wedge of wood and force between the metal and the
+adjoining tooth, thus bringing the metal against the cervical margin,
+and if a small film of rubber should still remain in the cavity, it may
+be forced out by using any flat burnisher which will reach it, or it can
+be dissolved out with a little chloroform. Fill from one-fourth to
+one-half of the cavity with tin, and complete the remainder with gold
+when the tooth is of good structure; this gives all the advantages of
+gold for an occlusal surface.
+
+Before beginning with the gold, have the tin solid and square across the
+cavity, and the rest of the cavity a good retaining form, the same as
+for gold filling; then begin with a strip of gold slightly annealed and
+mallet it into the tin, but do not place too great reliance upon the
+connection of the metals to keep the filling in place.
+
+On the same plan, proximal cavities in the anterior teeth can be filled,
+and also buccal cavities in molars, especially where they extend to the
+occlusal surface. The cervical margin should be well covered with tin
+thoroughly condensed, thus securing perfect adaptation, and a solid base
+for the gold with which the filling is to be completed. Time has fully
+demonstrated that the cervical margin is most liable to caries, and here
+the conservative and preservative qualities of tin make it specially
+applicable.
+
+"Electrolysis demonstrates to us that no single metal can be decomposed,
+but when gold and tin are used in the above manner they are united at
+the line of contact by electrolysis. The surface of both metals is
+exposed to the fluids of the mouth, and the oxid of tin is deposited on
+the tin, by reason of the current set up by the gold; thus some atoms of
+tin are dissolved and firmly attached to the gold, but the tin does not
+penetrate the gold to any great extent." (Dr. S. B. Palmer.)
+
+This connection of the metals assists in holding the filling in place,
+but it is more likely to break apart than if it was all gold. After
+electrolysis has taken place at the junction, it requires a cutting
+instrument to completely separate the tin and gold.
+
+For filling by hand pressure, use instruments with square ends and
+sides, medium serrations, and of any form or size which will best reach
+the cavity.
+
+For filling with the hand mallet, use instruments with medium
+serrations, and a steady medium blow with a four-ounce mallet; in force
+of blow we are guided by thickness of tin, size of plugger, and depth of
+serrations, strength of cavity-walls and margins, the same as in using
+gold. The majority of medium serrated hand mallet pluggers will work
+well on No. 10 tin of one, two, or three thicknesses. If the tin shows
+any tendency to slide, use a more deeply serrated plugger. The
+electro-magnetic, and mechanical (engine) mallet do not seem to work tin
+as well as the hand mallet or hand force, as the tendency of such
+numerous and rapid blows is to chop up the tin and prevent the making of
+a solid mass, and also injure the receiving surface of the filling. In
+using any kind of force, _always_ aim to carry the material to place
+before delivering the pressure, or blow.
+
+In order to obtain the best results, there must be absolute dryness, and
+care must be exercised, not thinking that because it is _tin_ it will be
+all right. Skill is required to make good tin fillings, as well as when
+making good gold fillings. Always use tapes narrower than the orifice of
+the cavity; they are preferable to rolls or ropes. After a few trials it
+is thought that every one will have the same opinion. A roll or rope
+necessarily contains a large number of spaces, wrinkles, or
+irregularities, which must be obliterated by using force in order to
+produce a solid filling; thus more force is employed, and more time
+occupied in condensing a rope, than a flat tape; the individual blow in
+one case may not be heavier than in the other, but the rope has to be
+struck more blows. The idea that a rope could be fed into a cavity with
+a plugger faster and easier than a tape has long ago been disproved.
+Many of the old-fashioned non-cohesive gold foil operators used flat
+tapes, as did also Dr. Varney, one of the kings of modern cohesive gold
+operators.
+
+The tape is made by folding any portion of a sheet of foil upon itself
+until a certain width and thickness is obtained. This tape is very
+desirable in small or proximal cavities where a roll or rope would catch
+on the margin and partially conceal the view.
+
+In the form of a tape, perhaps more foil can be put in a cavity, and
+there may be more uniform density than when ropes are used. Tapes can
+also be made by folding part of a sheet of foil over a thin, narrow
+strip of metal. Fold the tin into tapes of different lengths, widths,
+and thicknesses, according to the size of the cavity; then fold the end
+of the tape once or twice upon itself, place it at the base of any
+proximal cavity, and begin to condense with a foot plugger of suitable
+size, and if there is a pit, groove, or undercut which it does not
+reach, then use an additional plugger of some other form to carry the
+tin to place; fold the tape back and forth across the cavity, proceeding
+as for cohesive gold. In small proximal cavities a very narrow tape of
+No. 10, one thickness, can be used successfully. For cavities in the
+occlusal surface, use a tape as just described, generally beginning at
+the bottom or distal side, but the filling can be started at any
+convenient place, and with more ease than when using cohesive gold. In
+any case if the tin has a tendency to move when starting a filling,
+"Ambler's left-hand assistant" is used, by slipping the ring over the
+second finger of the left hand, letting the point rest on the tin. This
+instrument is especially valuable in starting cohesive gold (see Fig.
+6). This is the easiest, quickest, and best manner of making a good
+filling, relying upon the welding or cohesive properties of the tin.
+
+Many operators have not tried to unite the tin and make a solid mass;
+they seem to think that it cannot be accomplished, but with proper
+pluggers and manipulation it can be done successfully.
+
+[Illustration: FIG. 6.]
+
+For large occlusal or proximal cavities, the tapes may be folded into
+mats, or rolled into cylinders, and used on the plan of wedging or
+interdigitation, and good fillings can be produced by this method, but
+the advantage of cohesion is not obtained, and more force is required
+for condensing. They are, therefore, not so desirable as tapes,
+especially for frail teeth. When using mats or cylinders, the general
+form of the cavity must be depended upon to hold the filling in place.
+To make the most pliable cylinders, cut a strip of any desired width
+from a sheet of foil and roll it on a triangular broach, cutting it off
+at proper times, to make the cylinders of different sizes.
+
+A cylinder roller, designed by the author, is much superior to a broach.
+(See Fig. 7.) When the cavity is full, go over the tin with a mallet or
+hand burnisher, being careful not to injure the cavity-margin. Cut down
+occlusal fillings with burs or carborundum wheels, and proximal fillings
+with sharp instruments, emery strips or disks. After partially
+finishing, give the filling another condensing with the burnisher, then
+a final trimming and moderate burnishing; by this method a hard, smooth
+surface is obtained.
+
+Fillings on occlusal surfaces can be faced with No. 20 or 30 tin, and
+burnished or condensed, by using a burnisher in the engine, but do not
+rely upon the burnisher to make a good filling out of a poor one.
+
+[Illustration: FIG. 7.]
+
+By trimming fillings before they get wet, any defects can be remedied by
+cutting them out; then with a thin tape (one or two layers of No. 10)
+and serrated plugger proceed with hand or mallet force to repair the
+same as with cohesive gold.
+
+Another method of preparing tin for fillings is to make a flat, round
+sand mold; then melt chemically pure tin in a clean ladle and pour it
+into the mold; put this form on a lathe, and with a sharp chisel turn
+off thick or thin shavings, which will be found very tough and cohesive
+when freshly cut, but they do not retain their cohesive properties for
+any great length of time,--perhaps ten or twenty days, if kept in a
+tightly corked bottle. After more or less exposure to the air they
+become oxidized and do not work well, but when they are very thin they
+are soft, pliable, and cohesive as gold, and any size or form of filling
+can be made with them.
+
+Among the uses of tin in the teeth, the writer notes the following from
+Dr. Herbst, of Germany: "After amputating the coronal portion of the
+pulp, burnish a mat of tin foil into the pulp-cavity, thus creating an
+absolutely air-tight covering to the root-canal containing the remainder
+of the pulp; this is the best material for the purpose." There has been
+a great deal said about this method, pro and con, notably the latter.
+The writer has had no practical experience with it, and it need not be
+understood that he indorses it.
+
+If a pulp ever does die under tin, perhaps it will not decompose as
+rapidly as it otherwise would, owing to its being charged with
+tin-salts.
+
+The Herbst method of filling consists in introducing and condensing tin
+in cavities by means of smooth, highly tempered steel engine or hand
+burnishers. In the engine set of instruments there is one oval end
+inverted cone-shaped, one pear-shaped, and one bud-shaped. The revolving
+burnisher is held firmly against the tin, a few seconds in a place, and
+moved around, especially along the margins, not running the engine too
+fast. Complicated cavities are converted into simple ones by using a
+matrix, and proximal cavities in bicuspids and molars are entered from
+the occlusal surface. The tin foil is cut into strips, and then made
+into ropes, which are cut into pieces of different lengths; the first
+piece must be large enough so that when it is condensed it will lie
+firmly in the cavity without being held; thus a piece at a time is added
+until the cavity is full. The hand set of burnishers has four which are
+pear-shaped and vary in size, and one which is rather small and
+roof-shaped. In filling and condensing they are rotated in the hand
+one-half or three-quarters of a turn.
+
+Dr. Herbst claims a better adaptation to the walls of the cavity than by
+any other method. Proximal cavities in bicuspids and molars can easily
+be filled; the tin can be perfectly adapted against thin walls of enamel
+without fracturing them; less annoyance to the patient and less work for
+the dentist; can be done in half the time required for other methods.
+
+Fees should be reasonably large, certainly more than for amalgam, for
+we can save many teeth for a longer time than they could have been
+preserved with cohesive gold. Many are not able to pay for gold, but
+they want their teeth filled and _saved_, and it is expected that we
+will do it properly and with the right kind of material; thus it is our
+duty in such cases to use more tin and less amalgam.
+
+We should always take into consideration the amount of good accomplished
+for the patient,--the salvation of the tooth,--and if we are sure, from
+experience and observation, that the tin filling will last as long as a
+gold one in the same cavity, or longer, then the fee should be as much
+as for gold, with the cost of the gold deducted. The amount of the fee
+ought to be based upon the degree of intelligence, learning, and skill
+required; upon the amount of nervous energy expended; upon the draft
+made on the dentist's vitality; upon what benefit has been given the
+patient; upon the perfection of the result; and, everything else being
+equal, upon the time occupied; the value of this last factor being
+estimated in proportion to the shortness of it.
+
+
+
+
+CHAPTER VIII.
+
+
+Dr. Robinson's Fibrous and Textile Metallic Filling is a shredded
+metallic alloy, mostly tin, and has the appearance of woven or felt
+foil. It is prepared in a machine invented by the doctor especially for
+the purpose, and he gives directions for using as follows: "Cut the
+material into strips running with the selvage, and fill as you would
+with soft foil; use it in all surrounding walls, and finish with a
+mallet burnisher. Where the surface comes to hard wear, weld on gold
+with long, sharp serrated pluggers, and finish the same as with gold
+fillings. The advantage over gold for cervical, buccal, and lingual
+walls is the perfect ease with which it is adapted, and it can be
+burnished so as to be absolutely impervious to moisture. Sharp,
+coarse-serrated pluggers are particularly desirable when using hand
+pressure." It comes in one-half-ounce boxes, filled with sheets less
+than two inches square; the thin ones are used for filling, and the
+thick ones make good linings for vulcanite.
+
+This material is easy to manipulate, but great care is required in
+condensing at cavity-margins, so as to make a tight filling, and also
+not injure the margins. It makes as hard a surface as tin foil, and can
+be cut, polished, and burnished so that it is smooth and looks well; it
+can be used in temporary or chalky teeth, as a small amount of force
+condenses it. By using a matrix proximal cavities can be filled from
+one-fourth to one-half full, and the rest filled with gold, relying on
+the form of the cavity to hold the gold, regardless of its connection
+with the fibrous material. If the surface is not overmalleted so as to
+make it brittle or powdery, a strip of No. 4 cohesive gold, of four or
+five thicknesses, may be driven into it with a hand mallet and plugger
+of medium serrations; this union is largely mechanical, but of
+sufficient tenacity to make manipulation easy, as the material makes a
+solid foundation to build upon. After exposure to the oral fluids,
+electrolysis takes place at the junction of the metals.
+
+In 1884 Dr. Brophy said, "I have used Robinson's material for two years,
+and find it possesses good qualities, and can be used in deciduous
+teeth, first permanent molars, and cervical margins with better results
+than can be obtained with any other material by the majority of
+operators."
+
+Malleted with deeply serrated pluggers, it will make a filling which
+will not leak. It has saved many teeth from caries at the cervical
+margin where it might have recurred sooner had cohesive gold been used.
+In the mouth it changes color about the same as tin foil, and a few
+fillings did not maintain their integrity, but became crumbly and
+granular.
+
+For conducting properties it ranks about with tin, and fillings can be
+made more rapidly than with cohesive gold. We have used ounces of it,
+but time has proved that everything that can be done with it in filling
+teeth can also be accomplished as well and in some cases better with tin
+foil.
+
+In 1878 Dr. N. B. Slayton patented his Felt Foil, which was said to be
+tin cut into hair-like fibers by a machine, then pressed into small
+sheets and sold in one-half-ounce books, but it sold only to a very
+limited extent. Soon after this Dr. Jere Robinson, Sr., invented a
+machine and began the manufacture of a similar article, but he found he
+was infringing on the Slayton patent, so he purchased the Slayton
+machine and made satisfactory terms to continue his own manufacture of
+fibrous material. After this little was heard of Slayton's Felt Foil,
+but Robinson's was considerably used. The two materials look and are
+manipulated almost exactly alike. Dr. Robinson has both of
+above-mentioned machines now in his possession.
+
+Archibald McBride, of Pittsburg, Pa., in 1838, made a roll of a portion
+of a sheet of tin, and then used just enough gold to cover it, aiming
+to keep the gold on the surface, so as to have the filling look like one
+of all gold, and not with the idea of deriving any special benefit from
+the effects of wear or preservation as obtained by thus combining the
+two metals. The fee for a gold filling was one dollar; tin, fifty cents.
+Some operators have advocated using tin and gold (symbol Tg), rolled or
+folded together in alternate layers, thus exposing both metals to the
+fluids of the mouth; claiming that fillings can be made quicker, are not
+so subject to thermal changes, and can be inserted nearer the pulp than
+when gold is used. This may be true in comparison with gold, but these
+three claims are entirely met by using tin alone. Others say that this
+union of gold and tin will preserve the teeth as well as a correct gold
+filling, making no conditions or restrictions as to tooth-structure or
+location of cavity. They say that it preserves the cervical margin
+better than gold; that it expands _slightly_.
+
+A description of some different methods of combining and manipulating
+tin and gold is subjoined:
+
+(_a_) Two sheets of No. 4 cohesive gold and one of the same number of
+tin are used; place the tin between the gold, cut off strips, and use
+with hand or mallet force the same as cohesive gold; if non-cohesive
+gold is used, the strips can be folded into mats or rolled into
+cylinders, and are used on the wedging plan, the same as non-cohesive
+gold, or the strips can be folded back and forth in the cavity until it
+is full.
+
+(_b_) Lay a sheet of non-cohesive gold, No. 3, on a sheet of tin of the
+same number, cut off strips, roll into ropes and use as non-cohesive
+gold. It is easily packed and harder than tin, and has a preservative
+action on the teeth. Line the cavity with chloro-balsam as an insulator
+against possible currents and moisture; especially should this be done
+in large cavities or chalky teeth.
+
+(_c_) A sheet of non-cohesive gold, No. 4, is laid on a sheet of tin of
+the same number, cut into strips and rolled into cylinders, or folded
+into blocks, always in equal portions; then they will unite to the
+extent of two leaves. These fillings sometimes become a solid mass about
+the color of amalgam, and last very well, as the metals have become
+united by electrolysis. An excess of tin will be marked by lines or pits
+in the filling, showing where the tin has been disintegrated or
+dissolved by the chemical action which occurs on the surface exposed to
+moisture.
+
+No doubt, good fillings have been made by the above methods, yet some
+were granular, gritty, and were easily removed, while others were quite
+smooth and hard; probably in the first instance the proportion of tin
+and gold was not proper,--that is, not equal; or it was not well
+condensed. Tin being the positive element, it is more easily acted on
+and disintegrated by electrolysis (chemical action of the fluids).
+
+When this combination does become hard, it wears longer than tin on an
+occlusal surface, but we believe that in some cases where it was used
+the teeth could have been saved just as well with either tin or gold, or
+by filling part of the cavity with tin and the rest with gold.
+
+If tin foil is laid on 22-carat gold and vulcanized, it becomes
+thoroughly attached and will take a tin polish; the attraction or
+interchange of atoms takes place to this extent.
+
+This combination of tin and gold can be used at the cervical margin, or
+a cavity can be lined with it, and the remainder filled with cohesive or
+non-cohesive gold.
+
+"Tin and gold (Tg) folded or rolled together in equal portions possesses
+a greater number of desirable properties than any other material, for it
+is easily adapted, has antiseptic action and a lower conductivity than
+gold. A new filling is harder than tin, softer than gold, but after a
+time it becomes as hard as amalgam. It oxidizes and thus helps make
+tight margins, and is very useful at cervical margins; generally
+discolors, but not always, and does not discolor the tooth unless a
+carious portion has been left, and then only discolors that portion. In
+oral fluids it is indestructible if well condensed, otherwise it is
+crumbly. There is no change of form, except a _slight_ expansion, which
+does no harm. A weak electric current is set up between the gold and
+tin, and tin oxid is formed. The hardening and discoloration both depend
+upon the separation of the tin by the electrical action and its
+deposition on the surface of the gold. I generally prepare cavities the
+same as for non-cohesive gold, but a Tg filling may be held in a more
+shallow cavity and with less undercuts than for gold. Hand pressure is
+adopted, but a mallet may be used advantageously. Lay a sheet of No. 4
+non-cohesive gold on a sheet of No. 4 tin, then cut into strips and
+twist into ropes; keep the tin on the outside, for it does not tear as
+easily as gold. Carry the material against the walls and not against the
+base, otherwise the filling will be flat or concave; but should this
+occur, then force a wedge-shaped plugger into the center of the filling,
+and drive the material toward the walls, and then fill the hole or
+remove all the filling and begin anew.
+
+"In very deep cavities use a mat of Tg, dampened in carbolic acid and
+dipped in powdered thymol, as a base; this has an antiseptic action, and
+also prevents pressure on or penetration into the pulp.
+
+"Drs. Abbot, Berlin; Jenkins, Dresden; Sachs, Breslau, have observed
+tin-gold fillings from fifteen to twenty-five years, and say that for
+certain cases it is better than any other material. I use square-pointed
+pluggers (four-cornered), as part of the packing is done with the side
+of the plugger. Tg is useful in partly erupted molars, buccal cavities
+under the gums, occlusal cavities in temporary teeth, cavities where all
+decay cannot be removed. Use Tg with a gold capping in small, deep
+occlusal cavities, cavities with overhanging walls, occlusal cavities
+with numerous fissures, large, deep occlusal cavities near the pulp, in
+proximal cavities.
+
+"Line labial walls of incisors with non-cohesive gold, and fill the
+remainder with Tg. For repairing gold fillings I use Tg." (Dr. Miller,
+Berlin, _Dental Cosmos_, 1890.)
+
+Dr. Jenkins, of Dresden, says, "I use Tg in soft, imperfect teeth, of
+which there are plenty in Germany, because it has pliability,
+adaptability, slight susceptibility to thermal changes, makes a
+water-tight joint, very useful at cervical margins, and can be used with
+a minimum amount of pressure. When packed dry and with the gold next to
+the tooth, discoloration occurs only on the surface; packed wet, the
+whole discolors. I do not attribute its success to electrical action.
+Lay a sheet of No. 4 tin on a sheet of No. 4 non-cohesive gold, fold so
+as to keep the gold on the outside; use the strip with lateral pressure,
+doubling it upon itself."
+
+Dr. A. H. Thompson: "After several years' successful use of tin-gold, I
+commend it for approximal cavities, cervical margins, and frail walls.
+The oxid formed penetrates the enamel and dentin; if a filling wears
+down, cover the surface with gold."
+
+Dr. Pearson: "I do not like tin and gold in alternate layers. I prefer
+No. 10 tin foil."
+
+Dr. James Truman: "I believe that tin-gold has a positive value as a
+filling-material."
+
+"I prepare tin-gold by taking a sheet of No. 4 non- or semi-cohesive
+gold, fold them together (or twist them) so as to have the gold on the
+outside, and then fill any cavity with it. Since adopting the above
+combination I have almost abandoned amalgam. This is recommended on
+account of its density, ease of insertion, capacity for fine finish,
+non-conducting and non-shrinking qualities, and compatibility with
+tooth-substance. Those who have not used it will be surprised at the
+rapidity with which it can be manipulated. It may be employed in any
+cavity not exposed to view, also in crown, buccal, and approximal
+fillings which extend into the occlusal surface, as it offers an
+astonishing resistance to wear. It can be used anywhere that amalgam
+can, and with more certainty of non-leakage, and it has the additional
+advantage that it can be finished at the same sitting. Care is necessary
+in manipulating it, so as to avoid chopping. I use hand pressure when
+filling, and the mallet to condense the surface." (Dr. A. W. Harlan,
+_Independent Practitioner_, 1884.)
+
+"Pure tin foil is employed in connection with non-cohesive gold in
+filling proximal cavities in bicuspids and molars; a sheet of gold and a
+sheet of tin are folded together." (C. J. Essig: "Prosthetic
+Dentistry.")
+
+Dr. Benj. Lord says, "A combination in which I find great interest is in
+the use of soft or non-cohesive gold with tin foil. This is no novelty
+in practice, but I think that, for the most part, too great a proportion
+of tin has been used, and hence has arisen the objection that the tin
+dissolved in some mouths. I am satisfied that I myself until recently
+employed more tin than was well. I now use from one-tenth to one-twelfth
+as much tin as gold, and no disintegration or dissolving away of the
+tin ever occurs. I fold the two metals together in the usual way of
+folding gold to form strips, the tin being placed inside the gold. The
+addition of the tin makes the gold tougher, so that it works more like
+tin foil. The packing can be done with more ease and certainty; the
+filling, with the same effort, will be harder, and the edges or margins
+are stronger and more perfect.
+
+"The two metals should be thoroughly incorporated by manipulation. Then,
+after a time, there will be more or less of an amalgamation. By using
+about a sixteenth of tin, the color of the gold is so neutralized that
+the filling is far less conspicuous than when it is all gold, and I very
+often use such a proportion of tin in cavities on the labial surfaces of
+the front teeth.
+
+"If too much tin is employed in such cases, there will be some
+discoloration of the surface of the fillings; but in the proportion that
+I have named no discoloration occurs, and the surface of the filling
+will be an improvement on gold in color."
+
+"Dr. Howe. I would like to ask Dr. Lord whether, in referring to the
+proportions of tin and gold, he means them to be considered by weight?
+
+"Dr. Lord. No, not by weight, but by the width of the strip of tin and
+the width of the strip of gold. I get the proportions in that way, then
+lay the tin on the gold and fold the gold over and over, which keeps the
+tin inside the gold.
+
+"Dr. Howe. Will Dr. Lord tell us whether he refers to the same numbers
+of gold foil and tin foil; as, for instance, No. 4 gold and No. 4 tin?
+
+"Dr. Lord. I use the No. 5 gold, and tin, I think, of about the
+same number, but I always use No. 5 gold, both cohesive and
+non-cohesive."--_New York Odontological Society Proceedings_, 1893, page
+103.
+
+"Tin and gold, in the proportions generally used, do not present a
+pleasing color; when finished, it looks but little better than tin, and
+after a short time it grows dark, and sometimes black. I use five parts
+of gold to one of tin, prepared as follows: Lay down one sheet of
+Abbey's non-cohesive gold foil, No. 6; upon this place a sheet of No. 4;
+upon this place a sheet of White's globe tin foil, No. 4; upon this
+another sheet of Abbey's non-cohesive gold, No. 4; upon this a sheet of
+No. 6. Cut into five strips and crimp; the crimped strips are cut into
+pieces a little longer than the depth of the cavity to be filled; some
+of the strips are rolled into cylinders, others are left open, because
+easier to use in starting a filling. The color of this combination is
+slightly less yellow than pure gold, and hardens just as rapidly as when
+the proportions are one to one, but does not become quite as hard. This
+preparation is non-cohesive, and should be inserted by the wedge
+process. I use it in the grinding surface of molars and bicuspids,
+buccal cavities in molars and bicuspids, cervical fissure pits in
+superior incisors, proximal cavities in bicuspids and molars. If
+proximal cavities are opened from the occlusal surface, the last portion
+of the filling should be of cohesive gold to withstand mastication. In
+simple cavities I place as many pieces as can be easily introduced,
+using my pliers as the wedging instrument to make room for the last
+pieces, and then condense the whole. If the cavity is too deep for this,
+I use Fletcher's artificial dentin as a base, because it partly fills
+the cavity and the ends of the cylinders stick to it. After an
+approximal cavity is prepared, use a matrix held in place by wooden
+wedges; the cylinders are about one-eighth of an inch long, and
+condensed in two or three layers so as to secure perfect adaptation;
+hand pressure is principally used, but a few firm strokes with a hand
+mallet are useful. When ready to add the cohesive gold for the
+grinding-surface, a few pieces of White's crystal mat gold should first
+be used, because it adheres beautifully; thus a perfect union is
+secured, but I never risk adding the gold without leaving a little
+undercut for it in the tooth. By this method we obtain a beautiful
+contour filling in a short time. Fillings should be burnished and then
+polished with a fine strip, or moistened pumice on a linen tape. Where
+cohesive gold is used for the entire filling, in many cases the
+enamel-walls, already thin near the cervical margin, are made thinner by
+the unavoidable friction of the polishing strips, but tin and gold is so
+soft that a good surface is obtained in a few moments, and this danger
+is reduced to a minimum. The surface is as smooth as a cohesive gold
+filling, while such a surface is impossible with non-cohesive gold. In
+cavities which extend so far beyond the margin of the gum that it is
+impossible to adjust the rubber-dam, I prepare the cavity as usual, then
+adjust a matrix, disinfect, dry, and fill one-third full with tin and
+gold, then remove the matrix, apply the rubber, place matrix again in
+position, and complete the filling by adding a little tin and gold, then
+pure gold." (Dr. W. A. Spring, _Dental Review_, February, 1896.)
+
+Dr. T. D. Shumway says, "To have a scientific method of treatment, there
+certainly must be a recognition of what is known of the nature of
+tooth-structure. The method adopted more than a quarter of a century
+ago, and which is at present employed, does not accord with the
+teachings of the physiologist and microscopist; it is in direct
+opposition to natural law. Each new discovery in the minute structure of
+the teeth makes this more plain; pounding the teeth with a mallet cannot
+be defended on scientific grounds. That it has not resulted more
+disastrously is due to the wonderful recuperative energy of nature to
+repair injury. No one would think of attempting to arrest and prevent
+disintegration in any other vital organ by abrasion. Why, then, in
+operation on the teeth, should we reverse the plain, simple teaching of
+nature? Placing cohesive gold against the dentinal walls by pounding it
+to heal a lesion is opposed to natural law. Cohesive gold will not be
+mastered by force; if compelled to yield by superior strength, it seeks
+a way to release itself; it is easily coaxed, but not easily driven.
+Cohesive gold will unite with tin at an insensible distance just as
+cohesive gold unites with itself; this union takes place without force
+or pressure. Exactly what takes place when gold and tin are brought in
+contact in the way described we do not know; we can only say that there
+appears to be a perfect union. When cohesive gold was introduced to the
+profession, while it was softer than non-cohesive foil, it was found to
+resist under manipulation. This resistance is in accordance with the
+well-known law that all crystalline bodies, when unobstructed, assume a
+definite form. With gold the tendency is to a spherical form. The
+process of crystallization is always from within outward. The mallet was
+introduced to overcome the resistance caused by the development of the
+cohesive property. Pounding gold with a mallet only increases its
+crystallization. A crystalline body coming in contact with a fibrous one
+can neither be antiseptic nor preservative; a filling-material which
+possesses these properties must be one that corresponds or is in harmony
+with tooth-substance.
+
+"In the interglobular spaces there is a substance which is called
+amorphous or structureless, and a filling to be in harmony with this
+substance should be amorphous or structureless in its composition. The
+only materials we have which meet these conditions are gutta-percha and
+tin. It is its structureless character that gives to tin its value.
+Coming in contact with the living dentin, it is easily adapted, and does
+not excite inflammation; it does not interfere with the process going on
+within the teeth to heal the lesion caused by caries. A wound from a
+bullet made of tin, unless it struck a vital part, nature would heal,
+even if the cause of the wound was not removed, by encysting the ball.
+This process of nature of repairing injury by encysting the cause is of
+interest to the dentist in the study of suitable filling-materials. Tin
+is very useful at the cervical margin of cavities; it acts as an
+antiseptic or preservative, and reduces the liability to subsequent
+decay. It is our endeavor to obtain a filling that will preserve the
+teeth and reduce the liability to, if not wholly prevent, secondary
+decay. The law of correspondence is of more consequence than the
+mechanical construction of the filling. Tin can be used without that
+rigid adherence to mechanical rule that is necessary to retain a filling
+of cohesive gold; thus less of the tooth needs to be sacrificed.
+
+"Gold will unite with tin under certain conditions so as to form
+apparently a solid mass. By a combination of these metals, not by
+interlacing or incorporating one in the other, but by affinity, secured
+by simple contact, we have all the preservative qualities of tin
+combined with the indestructible properties of gold. For the base of the
+filling we have a material in harmony with tooth-substance, introduced
+in a way that is in accord with the law that governs all living bodies,
+and for the outside a crystalline substance that corresponds to the
+covering of the teeth. This covering of gold is a perfect shield to the
+base, and the field for the display of artistic skill in restoring
+contours is as broad as though gold was used entirely. Will a filling of
+this kind withstand mastication? There is in the economy of nature a
+provision made to overcome the resistance of occlusion. The teeth are
+cushioned in the jaw and yield under pressure. The elasticity of the
+substance of which the teeth are made is well understood. Ivory is the
+most elastic substance known. The teeth coming together is like the
+percussion of two billiard balls. Now a filling to save the teeth should
+correspond as nearly as possible with the tooth-substance; it should not
+be arbitrary, but elastic and yielding. Tin is interdigitous; it expands
+laterally, and is almost as easily introduced as amalgam, and when put
+in place does not have to be bound to be retained. Tin, with an outside
+covering of gold to protect it, makes a filling to which amalgam bears
+no comparison. In the light of scientific investigation there can be but
+one method--a method based upon the recognized principle that the
+_filling-material_ and the _manner_ of _introducing_ it shall correspond
+to and be in harmony with the living, vital organism with which it comes
+in contact.
+
+"After excavating, the cavity is treated with absolute alcohol, as
+cleanliness and thorough dryness are absolutely essential.
+
+"The _tin_ is put in with steel pluggers, after the method of wedging;
+it must be thoroughly condensed, so as to leave a smooth surface, and
+enough used to come up to where the enamel and dentin join.
+
+"The effect is not produced by incorporating or interlacing the gold
+with the tin; we rely upon the affinity of the two metals to retain the
+gold; no undercuts, angles, or pits are made in the tin, dentin, or
+enamel. The gold, extra cohesive from No. 4 to 40, is made to adhere to
+the tin by simple contact, without pressure or force; the union is not
+mechanical.
+
+"The instruments used for filling the remainder of the cavity with gold
+are Shumway's ivory points, which adapt the gold nicely to the margin.
+
+"The set consists of five and were patented in 1881, and have been used
+by me since that time for manipulating cohesive gold. One 'point' is for
+proximal cavities in the anterior teeth; three 'points' of different
+sizes are for occlusal cavities; one 'point' for proximal cavities in
+bicuspids and molars and labial and buccal cavities; the sides, edges,
+and ends of the 'points' are used, as the purpose is simply to obtain
+contact.
+
+"The 'point' shown full size in Fig. 8 is of more general application
+than any of the others, and is used for proximal cavities in bicuspids,
+also labial and buccal cavities. The handle is made of ebony, and has a
+silver ferrule, from which the ivory extends to the end and completes
+the instrument.
+
+"The metal pin in the end of the handle is for picking up and carrying
+the gold."
+
+[Illustration: FIG. 8.]
+
+Tin has been used successfully for completely lining cavities, filling
+the remainder with gold; it is also useful for repairing gold fillings.
+
+Two or three thicknesses of tin foil may be pressed into a cavity with a
+rubber point or hard piece of spunk, allowing it to come well out to the
+margin; filling the rest with amalgam.
+
+"As a lining it presents to dentin an amalgam of tin and mercury which
+does not discolor the dentin like ordinary amalgam, and helps do away
+with local currents on the filling, which is one cause of amalgam
+shrinkage in the mouth." (Dr. S. B. Palmer.)
+
+When caries extends to the bifurcation of roots, make a mat of two or
+three layers of tin, place it in the bifurcation and use it as a base in
+filling the rest of the cavity with amalgam.
+
+Tin is second in importance in alloys for amalgam, as it increases
+plasticity, prevents discoloration, reduces conductivity and edge
+strength, retards setting, favors spheroiding, therefore should not be
+the controlling metal.
+
+It will be noticed that when cavities are lined with tin foil, it only
+constitutes a small part of the filling, and that it has not been melted
+with the other metals in the alloy before being amalgamated.
+
+A thick mat of tin has been recommended as a partial non-conductor under
+amalgam fillings.
+
+Plastic tin can be made by pouring mercury into melted tin, or by mixing
+the fillings with mercury at ordinary temperatures; it has a whitish
+color, and if there is not too much mercury it occurs in the form of a
+brittle granular mass of cubical crystals. Generally amalgams of tin and
+mercury do not harden sufficiently, but forty-eight parts of mercury and
+one hundred of tin make a fairly good filling, said to have a
+therapeutical value; it should not be washed or squeezed before using,
+and "is not a chemical combination."
+
+"Tin unites with mercury in atomic proportions, forming a weak
+crystalline compound." (Dr. E. C. Kirk.)
+
+Mercury and tin readily unite as an amalgam under ordinary
+circumstances, and form a definite chemical compound having the formula
+Sn_{2}Hg. (Hodgen.)
+
+Another preparation of tin is known as stannous gold; it is manufactured
+in heavy sheets and used the same as cohesive gold foil, and can be
+easily manipulated, for it is rather plastic.
+
+Crystal tin for taking the place of tin foil:
+
+"Take chemically pure hydrochloric acid and dissolve tin foil in it
+until a saturated solution is obtained; this may be done speedily by
+heating the acid to a boiling point, or the same thing can be
+accomplished in a few hours with the acid cold; it is then chlorid of
+tin. It is then poured into a clean vessel and an equal quantity of
+distilled water added; then a clean strip of zinc is plunged into the
+solution, and tin crystals are deposited on the zinc; when there is
+sufficient thickness on the zinc, remove both, and slip the crystals off
+from the zinc into pure water, clean the zinc thoroughly, and reinsert
+for another coating. The character of the crystallization will be
+modified by the extent of the dilution of the solution in the first
+place. Wash the tin in pure water until all traces of the acid are
+removed, or a few drops of ammonia can be added to neutralize the acid.
+It was suggested that it would be desirable to have some acid remain in
+the tin for filling teeth in which there is no sensitive dentin. We have
+put in a few fillings, and it works beautifully, and makes firmer
+fillings than foil. It must be kept in water (probably alcohol is
+better). It is pure tin, unites perfectly, and works easier than foil."
+(Dr. Taft, _Dental Register of the West_, 1859.)
+
+For some years it was considered the best practice to enlarge all
+root-canals and fill them with gold; in many of these cases the crown
+cavities were filled with tin.
+
+Tin has been used for filling root-canals, but should there happen to be
+any leakage through the foramen or tooth-structure, the tin will
+discolor, and there may be infiltration into the crown, thus causing
+discoloration, which might be objectionable if the crown was filled with
+gold. Chloro-percha, gutta-percha, and oxychlorid of zinc are much
+better for this purpose.
+
+The apical quarter of a canal has been filled with tin, and the
+remainder with cement. Tin can be used for filling root-canals. Roll on
+a broach small triangular pieces of the foil into very small cone-shaped
+cylinders, carry to place, then withdraw the broach, and force in the
+cylinder with the same or a larger broach; sometimes it is necessary to
+use another broach, to push the cylinder off from the one on which it is
+rolled. Another method is to carry and pack into the canal by means of a
+broach, very narrow strips of No. 10 or 20 foil; or the apical third of
+the canal could be filled with gold and the rest with tin.
+
+"About four years ago I concluded to try tin for filling root-canals;
+then I began to look for patients whose general health was good, who had
+strong, hardy-looking teeth, and kept their mouths in good condition. I
+found one who answered all my requirements, with a molar to be filled,
+and they would not have it filled with gold, or could not, on account of
+the expense. I filled the canals with tin and the crown with amalgam.
+After filling thirty-eight molars in this way I stopped for
+developments. In six or seven weeks a lady returned with an inferior
+molar abscessed, but at the time it was filled the circumstances were
+such that it could not be properly treated. In nine months a gentleman
+for whom I had filled four molars returned with an inferior one
+abscessed. This is the sum-total of abscessed teeth where tin was used
+in the root-canals, at the end of four years. The others are in good
+condition, as I have seen them every six months. The roots were treated
+from four to six weeks with carbolic acid before filling." (Dr. A. W.
+Harlan, _Missouri Dental Journal_, 1872.)
+
+"Tin foil is just as good as gold for filling root-canals, as it is
+entirely innocuous and sufficiently indestructible, while its softness
+and pliability commend it. Where gold is to be used for the crown, it is
+better to fill the bulbous portion of the pulp-cavity with gold also, so
+as to weld these portions of gold together. The success of Dr. Harlan's
+treatment was about equal to what might be expected from the same number
+of teeth where the canals had been filled with gold." (Editor, _Missouri
+Journal_.)
+
+Shavings turned from a disk of pure tin have been used in combination
+with Watts's sponge gold for filling teeth, either by making a portion
+of the filling from each metal or using them indiscriminately.
+
+A mat of tin foil dipped in chloro-percha can be used to cap an exposed
+pulp, or a concave tin disk can be used for the same purpose. A mat of
+tin has been used over a slight exposure of the pulp, because of its
+slight conduction of heat and cold, thus avoiding much thermal
+irritation and stimulating recuperation.
+
+Some use Robinson's fibrous material as a surface for tin fillings,
+thinking that it is harder and will wear longer because of the erroneous
+notion that it has platinum in it.
+
+
+
+
+CHAPTER IX.
+
+
+Tin has been recommended for temporary fillings in sensitive cavities,
+because it is soft and easily packed in contact with the walls, has
+therapeutic value, and after a time, when the temporary filling is
+removed, the cavity is not as sensitive as formerly.
+
+It has been observed that starting gold in a sensitive cavity causes
+pain, but starting tin in the same place seldom does.
+
+As long as tin preserves its integrity it preserves the tooth, therefore
+tin fillings should not be repaired with amalgam, as their integrity may
+be destroyed. Cavities can be partly filled with tin and completed with
+sponge, fibrous, or crystalloid gold, after the manner described for
+beginning with tin and finishing with gold foil.
+
+"I advocated tin at the cervical wall, cervico-lingual and
+cervico-buccal angles to the thickness of 24 plate. Then complete the
+filling with gold. Some of my most successful efforts in saving soft
+teeth have been made in this way. This method has great value over gold
+for the whole filling, but there are two objections to it: First, it
+imparts to the cervical border the color and appearance of decay, so
+that in three cases where an instrument passed readily into the tin I
+have removed the fillings, without any necessity for it, not even
+finding any softening of the margins. Second, its use requires the same
+conditions of dryness, shape of cavity, delicate manipulation,
+inconvenience to patient, and strain upon the operator as when gold is
+used alone." (Dr. D. D. Smith, _Dental Cosmos_, 1883.) He admits that
+this method saves _soft_ teeth and also cervical margins. Do not those
+two very important factors more than counterbalance the color, and
+oversight of the dentist?
+
+Dryness is an essential in making the best filling with any material,
+and the time and strain consumed by the majority of operators in filling
+with tin is not more than one-half what it is in using gold.
+
+"I use tin at the cervical margin of all proximal cavities in bicuspids
+and molars. I prepare a matrix of orange-wood to suit each case, letting
+it cover about one-third of the cavity, then fill with tin condensed by
+hand force and automatic mallet; now split the matrix and carefully
+remove it piece by piece, so as not to disturb the tin; then trim and
+finish this part of the filling. Make another wooden matrix, which
+covers the tin and remainder of the cavity, and fit it snugly to place.
+Use a coarsely serrated plugger and begin packing non-cohesive gold
+into the tin, letting it fill about one-third more of the cavity; then
+complete the last third (surface) with cohesive gold. I have tested this
+method for twenty years, and it has given me splendid results. I always
+tell patients that there will appear sooner or later a slight
+discoloration near the gum, which must not be mistaken for caries." (Dr.
+A. P. Burkhart.)
+
+Another use for tin in the operating-room is found in Screven's
+"Gutta-percha-coated Tin Foil," a cohesive, antiseptic non-conductor, of
+which the inventor says: "Cement fillings that have been kept dry for
+ten hours after mixing will be much harder than those soon exposed to
+moisture, and they will retain that hardness though exposed to moisture
+afterward. This preparation will keep a filling perfectly dry in the
+mouth, and when removed the filling will be found hard as stone. There
+is nothing better for lining cavities, holding nerve-caps in position,
+holding a preparation in place when devitalizing a pulp where the tooth
+is so much broken away as to make it difficult to prevent a filling
+showing through the enamel, and for many other purposes."
+
+High-heat gutta-percha has been used as a base in deep occlusal, buccal,
+and approximal cavities, completing the fillings with tin. Occlusal
+cavities may be filled with tin; then after the filling is condensed and
+finished, drill out the center and fill with cohesive gold, not cutting
+away the tin so as to expose the margin; such fillings wear well, as
+much of the attritial force comes on the gold portion of the filling.
+
+With the exception of the part in brackets, the following article is
+from the _British Journal_, May, 1887:
+
+"If a person eats an oyster stew at 130° F., a gold filling would carry
+the difference between the temperature of the stew and that of the
+mouth, 130 - 98 = 32°, almost undiminished to the bottom of the cavity;
+allowing 2° of diminution, then the cavity around the gold filling has
+assumed 128°; now the person feels warm and drinks ice-water at 32°.
+Taking into consideration the specific heat of the gold filling, it will
+assume about 40°, which it carries with a diminution of the cold of
+about 4°,--that is, as if it was 44°,--into the interior of the cavity;
+then the cavity will assume 44°, the difference within one-tenth of a
+minute being 128 - 44 = 84°, a change which would produce a violent
+inflammation in any organ which was not accustomed to it. This
+derangement in the tooth means interruption of circulation, and young
+teeth will be most affected.
+
+"Thermal effect depends on heat-conducting power [gold is nearly four
+times as good a conductor of heat as tin] and also on specific heat, so
+the more the latter approaches that of the tooth the less it is liable
+to produce sudden changes [thus favoring tin]. Specific heat manifests
+itself by the speed of changes, while the heat-conducting power
+influences the intensity [then the intensity of heat in a gold filling
+would be three or four times as much as in a tin filling]. In speed gold
+produces this change in one-tenth of a minute" [tin in one-fifth,--that
+is, gold absorbs heat and expands about twice as fast as tin].
+
+In 1838 Dr. J. D. White introduced sharp-wedge-shaped instruments for
+filling teeth, and he claims to have been the first to use them; they
+pack laterally as well as downward, and present as small a surface to
+the filling as possible, so that the greatest effect may be produced
+upon a given surface with a given power. Rolls of either tin or gold are
+made by cutting any desirable portion from a sheet of No. 4 foil; cut
+this portion once transversely, place on a napkin or piece of chamois,
+then with a spatula fold a very narrow portion of the edge once upon
+itself; then with the spatula resting on the thickened edge draw the
+spatula away from it with gentle pressure, and the foil will follow in a
+roll.
+
+[Illustration: FIG. 9.]
+
+The old method of using rolls, ropes, and tapes or strips is the same,
+but we will describe one method of using tapes. (See Fig. 9.) A _strip_
+is a single thickness of foil in ribbon form; a strip folded lengthwise
+once, twice, or more forms a _tape_ of two, four, or more thicknesses of
+foil. The tin foil should be cut into strips and folded into tapes
+proportioned in width and thickness to the size of the cavity. One end
+of the tape is carried to the bottom of the cavity and then forced
+against the side opposite the point where we intend to finish; now
+remove the wedge-shaped plugger and catch the tape outside of the
+cavity, and fold another portion against that already introduced,
+letting all the folds extend from the bottom to a little beyond the
+margin. Proceed in this manner, with care and sufficient force, until
+the cavity is full, using for the last folds a small instrument.
+Condense the surface with a large plugger, then go over it carefully
+with a small instrument, and if any part yields, force in a wedge-shaped
+plugger and fill the opening in above-described manner; condense,
+burnish, and trim alternately until the surface is level with the
+cavity-margin. By extending the folds from the orifice to the base of
+the cavity, the liability of the tin to crumble or come out is
+effectually prevented, and by putting it in with a wedge-shaped plugger
+it is pressed out into all depressions of the walls.
+
+A later method of filling with tape or rope is to use wedge-shaped
+pluggers with sharp serrations, filling the _ends_ of the cavity, and as
+the two parts approach each other that next to the wall should be in
+advance of the rest, thus an opening will be left in the center which
+can be filled with a smaller tape or rope.
+
+Another old method: Take a piece of foil and roll it into a hard ball;
+then gradually work it into the cavity, being careful to have
+sufficient around the margin.
+
+Still another suggested method: Roll a piece of foil into a loose ball,
+place it in the cavity, and pass a wedge-shaped plugger into its center.
+This has the effect of spreading the tin toward the walls of the cavity,
+the opening to be filled with folds in a way already described. The
+wedge is used as often as it can be made to enter, filling each opening
+with folds; then condense the surface, trim, and burnish.
+
+[Illustration: FIG. 10.]
+
+The English give the Americans the credit of first using cylinders.
+Anyhow, Dr. Clark, of New Orleans, in 1855, used them made from
+non-cohesive gold, and also from gold and tin in alternate layers. (See
+Fig. 10.)
+
+Cylinders were used which were a little longer than the depth of the
+cavity, introduced with wedge-shaped pluggers around the walls, each one
+being closely adapted to the margin; then another row was added, which
+was forced firmly against the preceding, continuing this process until
+the cavity was full. The wedge, having a smooth end and sides, is forced
+into the center so as to drive the tin toward the sides of the cavity,
+being careful not to split the tooth; the opening is then filled with a
+cylinder. Now force a smaller-sized wedge into the center of the last
+cylinder, and into the opening introduce another cylinder, proceeding in
+this manner until the filling is solid. Then condense the ends of the
+cylinders, trim, and burnish. For the same operation more recent
+pluggers are wedge-shaped, with sharp, deep serrations. In these cases
+the filling is retained by the general form of the cavity and wedging
+within a certain limit, and not by cohesion of the different parts. For
+a time tin cylinders were prepared and put on sale at the dental depots.
+
+As far as we are aware, the first tin foil made use of in operative
+technics was by Dr. F. S. Whitslar, who removed a disk of German silver
+from an ivory knife-handle in 1845, then used hand pressure to fill the
+cavity with tin. In the college course of operative technics tin foil
+can be used, almost to the exclusion of gold foil, to demonstrate the
+manipulation of both cohesive and non-cohesive gold. Shavings scraped
+from a bar of tin are also useful in operative technics; they are more
+cohesive than foil.
+
+
+
+
+
+End of the Project Gutenberg EBook of Tin Foil and Its Combinations for
+Filling Teeth, by Henry L. Ambler
+
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+      The Project Gutenberg eBook of Tin Foil and Its Combinations for Filling Teeth, by Henry L. Ambler
+    </title>
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+<pre>
+
+The Project Gutenberg EBook of Tin Foil and Its Combinations for Filling
+Teeth, by Henry L. Ambler
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+Title: Tin Foil and Its Combinations for Filling Teeth
+
+Author: Henry L. Ambler
+
+Release Date: October 8, 2008 [EBook #26840]
+
+Language: English
+
+Character set encoding: ISO-8859-1
+
+*** START OF THIS PROJECT GUTENBERG EBOOK TIN FOIL ***
+
+
+
+
+Produced by Stephen Blundell and the Online Distributed
+Proofreading Team at http://www.pgdp.net (This file was
+produced from images generously made available by The
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+</pre>
+
+
+<h1><big>TIN FOIL</big><br />
+<span class="fs1">AND ITS</span><br />
+<span class="smcap">Combinations for Filling Teeth.</span></h1>
+
+<div class="bk1"><p class="center">BY</p>
+<h2>HENRY L. AMBLER, M.S., D.D.S., M.D.,</h2>
+<p class="center"><small>Professor of Operative Dentistry and Dental Hygiene, in the Dental Department<br />
+of Western Reserve University.<br />
+Member of the American Dental Association; of the Ohio State Dental<br />
+Society; of the Northern Ohio Dental Association;<br />
+of the Cleveland City Dental Society.</small></p></div>
+
+<p class="p1">PHILADELPHIA:<br />
+<big>THE S. S. WHITE DENTAL MFG. CO.,</big><br />
+LONDON:<br />
+<big>CLAUDIUS ASH &amp; SONS, Limited.</big><br />
+1897</p>
+
+<hr />
+
+<p class="p1">Copyright, <span class="smcap">Henry L. Ambler</span>, 1896.<br />
+All rights reserved.<br />
+Entered at Stationers Hall, London.</p>
+
+<hr /><p><span class='pagenum'><a name="Page_iii" id="Page_iii">[iii]</a></span></p>
+<h2>PREFACE.</h2>
+
+<p><span class="smcap">Believing</span> that sufficient and well-deserved prominence
+was not being given to the use of tin foil and its combinations,
+the author decided to present a brief historical r&eacute;sum&eacute;
+of the subject, together with such practical information as he
+possesses, before the profession in order that it may have the
+satisfaction of saving more teeth, since that is the pre-eminent
+function of the modern dentist. One object is to meet the
+demand for information in regard to the properties and uses
+of tin foil; this information has been sought to be given in
+the simplest form consistent with scientific accuracy. The
+present use of tin is a case of the "survival of the fittest,"
+because tin was used for filling teeth more than one hundred
+years ago. There is not a large amount of literature upon
+the subject, and no single text-book has treated the matter
+fully enough to answer the needs of both teacher and pupil.
+It is difficult for the student to collect and harmonize from
+the many different sources just the kind and amount of information
+required for his special use. Perhaps this work will
+be of assistance to scientific students and practical operators
+in the art of using tin foil, including all who wish in compact
+form an explanation of the facts and principles upon which
+the art is based. A good method to arouse in students an
+interest in the use of tin foil is to have them use it in operative
+technics, which is becoming an effective adjunct in every
+dental college. By this means a great factor will be brought
+to bear, and the result will be that hundreds of graduates<span class='pagenum'><a name="Page_iv" id="Page_iv">[iv]</a></span>
+every year will begin practice better qualified to save teeth
+than if they had not known whatever may be learned about
+this material. At the University of Pennsylvania, Department
+of Dentistry, session 1896-97, out of the total number
+of fillings made in the clinical department (fractions omitted)
+55 per cent. were gold, 15 per cent. tin, 10 per cent. amalgam.
+This shows that tin has some very strong friends in the persons
+of Professors Darby and Kirk.</p>
+
+<p>The historical sketch of the development of the subject is
+arranged in chronological order, and is given partly to show
+that some old ideas and methods were good, and some
+obviously incorrect when viewed in the light of more recent
+developments. Part of the history will be new to the oldest
+members of the profession, and the younger ones will certainly
+read it with interest. The work has been brought up
+to date by considering all the properties and methods available.
+More names, good opinions, and dates could have
+been given, but the writer believes that what is herein presented
+is enough to thoroughly substantiate his own opinions,
+experiments, and practical applications. Some of the illustrations
+have been made especially for this work; the others
+have been obtained through the courtesy of the owners.</p>
+
+<p>"Let not the foggy doctrine of the superiority of gold in
+all cases act on progress as the old medieval superstitions
+acted on astronomy, physiology, zoology. Truth sought
+after without misgiving, and the humblest as well as the
+highest evidence taken in every case, and acted on with skill
+and discrimination, will crown all with a high average of
+success."</p>
+
+<p>It is hoped that what has been said in this volume will
+enable those who study it to save more teeth, and stimulate
+them to make improvements on the material and methods,
+doing much better than has been described or suggested.</p>
+
+<p><span class="smcap">Cleveland, Ohio</span>, June, 1897.</p>
+
+<hr /><p><span class='pagenum'><a name="Page_v" id="Page_v">[v]</a></span></p>
+
+<div class="poem">
+<span class="i0">"With soft and yielding lamina, and skill,<br /></span>
+<span class="i0">The practiced dental surgeon learns to fill<br /></span>
+<span class="i0">Each morbid cavity, by caries made,<br /></span>
+<span class="i0">With pliant tin; when thus the parts decayed<br /></span>
+<span class="i0">Are well supplied, corrosion, forced to yield<br /></span>
+<span class="i0">To conquering art the long-contested field,<br /></span>
+<span class="i0">Resigns its victim to the smiles of peace,<br /></span>
+<span class="i0">And all decay and irritation cease."<br /></span>
+<div class="rgt">(<i>Solyman Brown.</i>)</div></div>
+
+<div class="bk2">The quantity of tin foil used measures the number of teeth
+saved with <i>metals</i> in any country during any historical period.</div>
+
+<hr /><p><span class='pagenum'><a name="Page_vii" id="Page_vii">[vii]</a></span></p>
+<h2>CONTENTS.</h2>
+
+<div class='center'>
+<table border="0" cellpadding="0" cellspacing="0" summary="">
+<tr><td class="rgt" colspan="2"><small>PAGE</small></td></tr>
+<tr><td class="td1" colspan="2">CHAPTER I.</td></tr>
+<tr><td class="td2">Antiquity of Tin&mdash;Alchemistic Name&mdash;Medical Use&mdash;Where
+Found&mdash;Purity Obtained&mdash;Physical Characteristics</td><td class="rgt"><a href="#Page_1">1</a></td></tr>
+
+<tr><td class="td1" colspan="2">CHAPTER II.</td></tr>
+<tr><td class="td2">History of the Use of Tin Foil, 1783-1844</td><td class="rgt"><a href="#Page_7">7</a></td></tr>
+
+<tr><td class="td1" colspan="2">CHAPTER III.</td></tr>
+<tr><td class="td2">History Continued, 1845-1895</td><td class="rgt"><a href="#Page_15">15</a></td></tr>
+
+<tr><td class="td1" colspan="2">CHAPTER IV.</td></tr>
+<tr><td class="td2">Columbian Dental Congress&mdash;Opinions on Tin Foil&mdash;Reasons
+for Using&mdash;Manufacture in United States&mdash;Number
+and Weight of Foil&mdash;Cohesion&mdash;Good
+Qualities of Tin Foil&mdash;Temporary Teeth&mdash;Thermal
+Changes&mdash;Calcification&mdash;Chalky Teeth</td><td class="rgt"><a href="#Page_27">27</a></td></tr>
+
+<tr><td class="td1" colspan="2">CHAPTER V.</td></tr>
+<tr><td class="td2">Discoloration of Tin&mdash;Decomposition of Food&mdash;Sulfids&mdash;Oxids&mdash;Galvanic,
+Therapeutic, and Chemical Action</td><td class="rgt"><a href="#Page_40">40</a></td></tr>
+
+<tr><td class="td1" colspan="2">CHAPTER VI.</td></tr>
+<tr><td class="td2">White Caries&mdash;Gold and Tin as Conductors&mdash;Wearing
+Away of Fillings&mdash;Poor Foil&mdash;Buccal Cavities&mdash;Number
+of Years Fillings Last&mdash;Strips or Tapes for<span class='pagenum'><a name="Page_viii" id="Page_viii">[viii]</a></span>
+Filling&mdash;Number 10 Foil&mdash;Form of Cavities&mdash;Shields&mdash;Matrices&mdash;Condensing&mdash;Finishing&mdash;Cervical
+Margins&mdash;Filling
+Anterior Teeth&mdash;Lining with Gold</td><td class="rgt"><a href="#Page_49">49</a></td></tr>
+
+<tr><td class="td1" colspan="2">CHAPTER VII.</td></tr>
+<tr><td class="td2">Filling, part Tin, part Gold&mdash;Cervical Margin Liable to
+Caries&mdash;Electrolysis&mdash;Hand Pressure&mdash;Hand Mallet&mdash;Tapes
+and Ropes Compared&mdash;Manner of Preparing
+Foil&mdash;Starting the Filling&mdash;Cylinders&mdash;Mats&mdash;Facing
+and Repairing&mdash;Tin Shavings&mdash;Dr. Herbst's Method&mdash;Fees</td><td class="rgt"><a href="#Page_56">56</a></td></tr>
+
+<tr><td class="td1" colspan="2">CHAPTER VIII.</td></tr>
+<tr><td class="td2">Dr. Robinson's Fibrous and Textile Metallic Filling&mdash;Tin
+and Gold combined (Tg), Methods of Preparing
+and Using&mdash;Lining Cavities with Tin&mdash;Tin and Amalgam&mdash;Plastic
+Tin&mdash;Stannous Gold&mdash;Crystal Tin&mdash;Filling
+Root-Canals&mdash;Tin and Watts's Sponge Gold&mdash;Capping
+Pulps</td><td class="rgt"><a href="#Page_66">66</a></td></tr>
+
+<tr><td class="td1" colspan="2">CHAPTER IX.</td></tr>
+<tr><td class="td2">Temporary Fillings&mdash;Sensitive Cavities&mdash;Integrity&mdash;Tin
+with Sponge, Fibrous, and Crystallized Gold&mdash;Tin
+at Cervical Margin&mdash;Filling Completed with Gold&mdash;Gutta-Percha
+and Tin&mdash;Occlusal Cavities with Tin
+and Gold&mdash;Comparison of Gold with Tin&mdash;Wedge-shaped
+Instruments&mdash;Old Method of Using Rolls,
+Ropes, Tapes, or Strips&mdash;Later Method&mdash;Filling with
+Compact and Loose Balls&mdash;Cylinder Fillings&mdash;Operative
+Technics</td><td class="rgt"><a href="#Page_91">91</a></td></tr>
+</table></div>
+
+<hr /><p><span class='pagenum'><a name="Page_1" id="Page_1">[1]</a></span></p>
+<h2>CHAPTER I.</h2>
+
+<p><span class="smcap">Moses</span>, who was born 1600 B.C., mentions tin,
+and history records its use 500 B.C., but not for
+filling teeth; much later on, the Ph&#339;nicians took it
+from Cornwall, England, to Tyre and Sidon.</p>
+
+<p>The alchemistic name for tin is Jove, and in the
+alchemistic nomenclature medicinal preparations
+made from it are called Jovial preparations.</p>
+
+<p>Hindoo native doctors give tin salts for urinary
+affections. Monroe, Fothergill, and Richter claim
+to have expelled worms from the human system,
+by administering tin filings.</p>
+
+<p>Blackie, in "Lays of Highlands and Islands," referring
+to tin as money, says,&mdash;</p>
+
+<div class="poem" style="width: 18em;">
+<span class="i0">"And is this all? And have I seen the whole<br /></span>
+<span class="i0">Cathedral, chapel, nunnery, and graves?<br /></span>
+<span class="i0">'Tis scantly worth the tin, upon my soul."<br /></span>
+</div>
+
+<p>"Tin-penny."&mdash;A customary duty formerly paid
+to the tithingmen in England for liberty to dig in
+the tin-mines.</p>
+
+<p>In 1846, Tin (Stannum, symbol Sn) was found
+in the United States only at Jackson, N. H. Since
+then it has been found, to a limited extent, in West
+Virginia and adjoining parts of Ohio, North Carolina,<span class='pagenum'><a name="Page_2" id="Page_2">[2]</a></span>
+Utah, and North Dakota. The richest tin
+mines of the world, however, are in Cornwall,
+England, which have been worked from the time of
+the Ph&#339;nician discovery.</p>
+
+<p>The tin which is found in Malacca and Banca,
+India, is of great purity, and is called "Straits Tin"
+or "Stream Tin." It occurs in alluvial deposits
+in the form of small rounded grains, which are
+washed, stamped, mixed with slag and scori&aelig;, and
+smelted with charcoal, then run into basins, where
+the upper portion, after being removed, is known
+as the best refined tin. Stream tin is not pure
+metallic tin, but is the result of the disintegration
+of granitic and other rocks which contain veins of
+tinstone. Banca tin is 99.961 parts tin, 0.019 iron,
+0.014 lead in 100 parts; it is sold in blocks of 40 and
+120 pounds, and a bar 0.5 meter long, 0.1 broad,
+0.005 deep can be bent seventy-four times without
+being broken. Subjected to friction, tin emits a
+characteristic odor.</p>
+
+<p>Tin in solution is largely used in electro-metallurgy
+for plating. Pure tin may be obtained by
+dissolving commercial tin in hydrochloric acid, by
+which it is converted into stannous chlorid; after
+filtering, this solution is evaporated to a small
+bulk, and treated with nitric acid, which converts it
+into stannic oxid, which in turn is thoroughly<span class='pagenum'><a name="Page_3" id="Page_3">[3]</a></span>
+washed and dried, then heated to redness in a crucible
+with charcoal, producing a button of tin which
+is found at the bottom of the crucible.</p>
+
+<p>Pure tin may be precipitated in quadratic crystals
+by a slight galvanic current excited by immersing
+a plate of tin in a strong solution of stannous
+chlorid; water is carefully poured in so as not to
+disturb the layer of tin solution; the pure metal will
+be deposited on the plate of tin, at the point of
+junction of the water and metallic solution.</p>
+
+<p>In the study of tin as a material for filling teeth,
+we have deemed it expedient to consider some of
+its physical characteristics, in order that what follows
+may be more clearly understood.</p>
+
+<p>Tin possesses a crystallized structure, and can be
+obtained in well-formed crystals of the tetragonal
+or quadratic system (form right square prism), and
+on account of this crystalline structure, a bar of
+tin when bent emits a creaking sound, termed the
+"cry of tin;" the purer the tin the more marked the
+cry.</p>
+
+<p>The specific gravity is 7.29; electrical state positive;
+fusing point 442&deg; F.; tensile strength per
+square inch in tons, 2 to 3. Tensile strength is the
+resistance of the fibers or particles of a body to
+separation, so that the amount stated is the weight<span class='pagenum'><a name="Page_4" id="Page_4">[4]</a></span>
+or power required to tear asunder a bar of pure tin
+having a cross-section of one square inch.</p>
+
+<p>Tenacity: Iron is the most tenacious of metals.
+To pull asunder an iron wire 0.787 of a line in
+diameter requires a weight of 549 lbs. To pull
+asunder a gold wire of the same size, 150 lbs.; tin
+wire, 34 lbs.; gold being thus shown to be more
+than four times as tenacious as tin. (Fractions
+omitted.)</p>
+
+<p>Malleability: Pure tin may be beaten into leaves
+one-fortieth of a millimeter thick, thus requiring
+1020 to make an inch in thickness. Miller states
+that it can be beaten into leaves .008 of a millimeter
+thick, thus requiring 3175 to make an inch in
+thickness. Richardson says that ordinary tin foil
+is about 0.001 of an inch in thickness.</p>
+
+<p>If the difficulty with which a mass of gold (the
+most malleable of metals) can be hammered or
+rolled into a thin sheet without being torn, be taken
+as one, then it will be four times as difficult to
+manipulate tin into thin sheets.</p>
+
+<p>Ductility: If the difficulty with which gold (the
+most ductile of metals) can be drawn be taken as
+one, then it will be seven times as difficult to draw
+tin into a wire. At a temperature of 212&deg; it has
+considerable ductility, and can be drawn into wire.</p>
+
+<p>Among the metals, silver is the best conductor of<span class='pagenum'><a name="Page_5" id="Page_5">[5]</a></span>
+heat. If the conductivity of silver be taken as 100,
+then the conducting power of gold would be 53.2;
+tin, 14.5; gold being thus shown to be nearly four
+times as good a conductor of heat as tin. Among
+the metals, silver is the best conductor of electricity.
+If its electrical conductivity be taken at
+100, then the conducting power of gold would be
+77.96; tin, 12.36; gold being thus shown to be more
+than six times as good a conductor of electricity as
+tin.</p>
+
+<p>Resistance to air: If exposed to dry, pure air,
+tin resists any change for a <i>great</i> length of time, but
+if exposed to air containing moisture, carbonic acid,
+etc., its time resistance is reduced, although even
+then it resists corrosion much better than copper
+or iron.</p>
+
+<p>As to linear expansion, when raised from 32&deg; to
+212&deg; F., aluminum expands the most of any of the
+metals. Taking its expansion as 1, that of tin
+would be 3, <i>i.e.</i>, aluminum expands three times as
+much as tin. (Dixon, "Vade Mecum.")</p>
+
+<p>Solids generally expand equally in all directions,
+and on cooling return to their original shape.
+Within certain limits, metals expand uniformly in
+direct proportion to the increase in temperature,
+but the rate of expansion varies with different
+metals; thus, under like conditions, tin expands<span class='pagenum'><a name="Page_6" id="Page_6">[6]</a></span>
+nearly twice (1<span class="abv">3</span>&#8260;<span class="blw">5</span>) as much as gold, but the <i>rate</i> of
+expansion for gold is nearly twice (1<span class="abv">7</span>&#8260;<span class="blw">10</span>) that of
+tin.</p>
+
+<p>The capacity for absorbing heat varies with each
+metal; that of gold is about twice (1<span class="abv">3</span>&#8260;<span class="blw">4</span>) that of tin.</p>
+
+<p>Tin has a scale hardness of about 4, on a scale of
+12 where lead is taken as the softest and platinum
+the hardest. (Dixon, "Vade Mecum.")</p>
+
+<p>Tin has a scale hardness of about 2. (Dr. Miller.)</p>
+
+<p>To fuse a tin wire one centimeter in diameter
+requires a fusing current of electricity of 405.5
+amperes. Up to 225&deg; C., the rise in resistance to
+the passage of an electric current is more rapid in
+tin than in gold. In some minerals the current
+follows the trend of the crystals.</p>
+
+<p>Gold wire coated with tin, and held in the flame
+of a Bunsen burner, will melt like a tin wire. At
+1600&deg; to 1800&deg; tin boils and may be distilled.</p>
+
+<hr /><p><span class='pagenum'><a name="Page_7" id="Page_7">[7]</a></span></p>
+<h2>CHAPTER II.</h2>
+
+<p><span class="smcap">The</span> largest and most complete dental library in
+the world is owned by Dr. H. J. McKellops, of St.
+Louis. Upon his cheerful invitation, the writer
+visited that "Mecca," and through his kindness and
+assistance a complete search was made, which resulted
+in obtaining a great portion of the following
+historical facts with reference to the use of tin in
+dentistry:</p>
+
+<p>"In 1783 I stopped a considerable decay in a
+large double under tooth, on the outside of the
+crown or near the gums, with fine tin foil, which
+lasted for a good number of years." ("A Practical
+and Domestic Treatise on Teeth and Gums," by
+Mr. Sigmond, Bath, England, 1825.)</p>
+
+<p>"Fine tin foil or gold leaf may be injected into a
+cavity successfully, and retained securely for many
+years." (Joseph Fox, Dover, England, 1802.)</p>
+
+<p>"The statement has been made several times that
+tin foil was used in the United States for filling
+teeth as early as 1800, at which time dentistry began
+to be cultivated particularly as a science and
+art, and was beginning to be regarded as of more
+importance than it formerly had been. The writer
+has not found any record of its use in this country<span class='pagenum'><a name="Page_8" id="Page_8">[8]</a></span>
+earlier than 1809. Tin may often be employed
+with entire confidence. I have seen fillings forty-one
+years old (made in 1809) and still perfect.
+Several molars had four or five plugs in them,
+which had been inserted at different periods during
+the last half-century. I prefer strips cut from six
+sheets laid upon each other. If the foil is well connected,
+the cut edges will adhere firmly; if they do
+not, the foil is not fit for use." (Dr. B. T. Whitney,
+<i>Dental Register of the West</i>, 1850.) First
+reference to the fact that tin is adhesive.</p>
+
+<p>"Tin is desirable in all unexposed cavities. It
+has a stronger affinity for acetic, citric, tartaric,
+malic, lactic, and nitric acids than the tooth has: a
+good material where the secretions are of an acid
+character, it is better that the filling should waste
+away than the tooth. One cavity in my mouth
+was filled with gold, decay occurred, the filling was
+removed; cavity filled with oxychlorid, which produced
+pain; filling removed; cavity filled with
+gutta-percha, still experienced pain; filling removed;
+cavity filled with tin, and pain ceased in an
+hour. A tin filling was shown in New York which
+was sixty years old; made in 1811." (Dr. E. A.
+Bogue, <i>British Journal of Dental Science</i>, 1871.)</p>
+
+<p>"I have lately been removing tin pluggings (the
+juices of the mouth having oxidated and dissolved<span class='pagenum'><a name="Page_9" id="Page_9">[9]</a></span>
+away the metal, so as to expose the teeth to decay)
+from teeth which I plugged fifteen years ago (1818)
+for the purpose of re-stopping with gold, and have
+in almost every instance found the bone of the
+tooth at the bottom of the pluggings perfectly
+sound and protected from decay." (J. R. Spooner,
+Montreal, 1833.)</p>
+
+<p>In 1800 the number of dentists in the United
+States was about one hundred, and many of them
+were using tin foil for filling teeth.</p>
+
+<p>In 1822 tin was employed by the best dentists,
+with hardly an exception; it grew in favor, especially
+for large cavities in molars, and for a cheaper
+class of operations than gold, but tin was not generally
+used until 1830. ("History of Dental and
+Oral Science in America.")</p>
+
+<p>"Lead, tin, and silver corrode and become more
+injurious than the original disease, and will in every
+case ultimately prove the cause of destruction to
+the tooth, which might have been preserved by
+proper treatment." (Leonard Koecker, 1826, and
+"New System of Treating the Human Teeth," by
+J. Paterson Clark, London, 1829 and 1830.)</p>
+
+<p>"Tin in situations out of reach of friction in mastication,
+as between two teeth, is like the tooth
+itself apt to be decomposed by acidity unless kept
+very clean." ("Practical and Familiar Treatise on<span class='pagenum'><a name="Page_10" id="Page_10">[10]</a></span>
+Teeth and Dentism," J. Paterson Clark, London,
+1836.) Refer to what the same author said in
+1829.</p>
+
+<p>"Tin is used as a plugging material." ("The
+Anatomy, Physiology, and Diseases of the Teeth,"
+by Thomas Bell, F.R.S., London, 1829.)</p>
+
+<p>"Silver and tin foil, although bright when first
+put in a cavity, very soon change to a dark hue,
+resembling the decayed parts of the teeth which are
+of a bluish cast; besides this, they are not sufficiently
+pure to remain in an unchanged state, and
+frequently they assist in the destruction of a tooth
+instead of retarding it." ("Familiar Treatise on
+the Teeth," by Joseph Harris, London, 1830.)</p>
+
+<p>"Tin is objectionable on account of rapid oxidation
+and being washed by the saliva into the
+stomach, as it may materially disorder it; the filling
+becomes so reduced that the cavity in which it has
+been inserted will no longer retain it, and acid fruits
+influence galvanic action." ("Every Man his Own
+Dentist," Joseph Scott, London, 1833.)</p>
+
+<p>In 1836 Dr. Diaz, of Jamaica, used tin foil for
+filling teeth.</p>
+
+<p>"Gold is now preferred, though tin, from its
+toughness when in the leaf, is perhaps the most
+suitable. Americans are superior to British in<span class='pagenum'><a name="Page_11" id="Page_11">[11]</a></span>
+filling." ("Plain Advice on
+Care of the Teeth," Dr. A.
+Cameron, Glasgow, 1838.)</p>
+
+<div class="figl" style="width: 55px;"><a name="Fig_1" id="Fig_1"></a>Fig. 1.
+<img src="images/001.png" width="55" height="381" alt="" title="" />
+</div>
+
+<div class="figr" style="width: 51px;"><a name="Fig_2" id="Fig_2"></a>Fig. 2.
+<img src="images/002.png" width="51" height="460" alt="" title="" />
+</div>
+
+<p>"Tin foil is used for filling
+teeth." (S. Spooner,
+New York, 1838, "Guide to
+Sound Teeth.")</p>
+
+<p>In 1838 Archibald McBride,
+of Pittsburg, Pa.,
+used tin for filling cavities
+of decay.</p>
+
+<p>The following facts were
+learned from Dr. Corydon
+Palmer: E. E. Smith, who
+had been a student of John
+and William Birkey, in Philadelphia,
+came to Warren,
+Ohio, in 1839, and among
+other things made the first
+gold plate in that part of the
+country. In operating on
+the anterior teeth, he first
+passed a separating file between
+them, excavated the cavity, and
+prepared the foil, <i>tin</i> or gold, in tapes
+which were cut transversely, every
+eighth of an inch, about three-quarters<span class='pagenum'><a name="Page_12" id="Page_12">[12]</a></span>
+of the way across. <a href="#Fig_1">Fig. 1</a> shows the size of tape
+and the manner of cutting. With an instrument
+(<a href="#Fig_2">Fig. 2</a>) he drew the foil in from the labial surface,
+using such portion of the tape as desired.</p>
+
+<p>The instrument from which the illustration was
+made was furnished by Dr. Palmer, and is shown
+full size. Instruments for use on posterior teeth
+were short and strong, with as few curves as possible;
+no right and left cutters or pluggers were
+used, and none of the latter were serrated, but had
+straight, tapering round points, flat on the ends,
+and of suitable size to fill a good portion of the
+cavity. He used what was termed Abbey's chemically
+pure tin foil, forcing it in hard, layer upon
+layer,&mdash;as he expressed it, "smacked it up." In
+this manner he made tin fillings that lasted more
+than thirty years.</p>
+
+<p>In 1839 Dr. Corydon Palmer filled teeth with tin
+foil, also lined cavities with gold and filled the remainder
+with tin. In the same year he filled crown
+(occlusal) cavities one-half full with tin and the
+other half with gold, allowing both metals to come
+to the surface, on the same plan that many proximal
+cavities are now filled. (See <a href="#Fig_3">Fig. 3</a>, showing
+about one-half of the cavity nearly completed with
+tin cylinders. The same plan was followed when
+strips, or ropes, were used.)<span class='pagenum'><a name="Page_13" id="Page_13">[13]</a></span></p>
+
+<p>"I filled cavities about two-thirds full with tin,
+and finished with gold." (S. S. Stringfellow,
+<i>American Journal of Dental Science</i>, 1839.)</p>
+
+<p>"Tin foil is greatly used by some American dentists,
+but it is not much better than lead leaf."
+("Surgical, Operative, and Mechanical Dentistry,"
+L. Charles De Londe, London, 1840.)</p>
+
+<p>"In 1841 there were about twelve hundred dentists
+in the United States, many of whom were
+using tin, and there are circumstances under which
+it may be used not only with impunity, but advantage,
+but it is liable to change." (Harris.)</p>
+
+<div class="figc" style="width: 195px;"><a name="Fig_3" id="Fig_3"></a>Fig. 3.
+<img src="images/003.png" width="195" height="217" alt="" title="" />
+</div>
+
+<p>"I put in tin fillings, and at the end of thirty
+years they were badly worn, but there was no
+decay around the margins." (Dr. Neall, 1843.)</p>
+
+<p>In 1843 Dr. Amos Westcott, of Syracuse, N. Y.,<span class='pagenum'><a name="Page_14" id="Page_14">[14]</a></span>
+filled the base of large cavities with tin, completing
+the operation with gold.</p>
+
+<p>"Tin is used in the form of little balls, or tubes,
+but folds are better; introduce the metal gradually,
+taking care to pack it so that it will bear equally
+upon all points; the folds superimpose themselves
+one upon the other; thus we obtain a successive
+stratification much more exact and dense, and it is
+impossible there can be any void." ("Theory and
+Practice of Dental Surgery," J. Lefoulon, Paris,
+1844.)</p>
+
+<hr /><p><span class='pagenum'><a name="Page_15" id="Page_15">[15]</a></span></p>
+<h2>CHAPTER III.</h2>
+
+<p>"<span class="smcap">Besides</span> gold, the only material which can be
+used with any hope of permanent success is tin foil.
+Some dentists call it <i>silver</i>, and a tooth which cannot
+be filled with it cannot be filled with anything
+else so as to stop decay and make it last very long.
+It can be used only in the back teeth, as its dark
+color renders it unsuitable for those in front.
+When the general health is good, and the teeth
+little predisposed to decay, this metal will preserve
+them as effectually perhaps as gold; but where the
+fluids of the mouth are much disordered it oxidizes
+rapidly, and instead of preserving the teeth rather
+increases their tendency to decay." (Dr. Robert
+Arthur, Baltimore, 1845, "A Popular Treatise on
+the Diseases of the Teeth.")</p>
+
+<p>The false idea that a patient must have good
+health, normal oral fluids, and teeth little predisposed
+to decay, or else if filled with tin the decay
+would be hastened, originated with a German or
+English author, and has been handed down in
+works published since early in 1800. It even crept
+into American text-books as late as 1860, the
+authors of which now disbelieve it.</p>
+
+<p>"Tin undergoes but little change in the mouth,<span class='pagenum'><a name="Page_16" id="Page_16">[16]</a></span>
+and may be used with comparative safety." ("Surgical,
+Mechanical, and Medical Treatment of the
+Teeth," James Robinson, London, 1846.)</p>
+
+<p>"Tin is soft, and can be easily and compactly
+introduced, but it is more easily acted on by the
+secretions of the mouth than gold and is less durable,
+but in the mouth of a healthy person <i>it will last
+for years</i>. Still, inasmuch as it cannot be depended
+on in <i>all</i> cases, we are of the opinion that it should
+<i>never</i> be employed." ("The Human Teeth,"
+James Fox, London, 1846.)</p>
+
+<p>The italics are ours. Every metal has a limited
+sphere of usefulness, and it should not be expected
+that tin will contend single-handed against all the
+complicated conditions which caries presents.</p>
+
+<p>"Of all the cheaper materials, I consider tin the
+best by far, and regard its use fully justifiable in
+deciduous teeth and in large cavities, as it is not
+every man who can afford the expense of nine
+leaves of gold and four hours of labor by a dentist
+on a single tooth." (Dr. Edward Taylor, <i>Dental
+Register of the West</i>, 1847.)</p>
+
+<p>"I consider tin good for any cavity in a chalky
+tooth: it will save them better than anything else."
+(Dr. Holmes, 1848.)</p>
+
+<p>"Tin can be used as a temporary filling, or as a
+matter of economy. It may be rendered impervious<span class='pagenum'><a name="Page_17" id="Page_17">[17]</a></span>
+to air and dampness, but it corrodes in most
+mouths, unless it comes in contact with food in
+chewing, and then it rapidly wears away; it does
+not become hard by packing or under pressure, and
+that it forms a kind of a union with the tooth is
+ridiculous." (Dr. J. D. White, 1849, <i>Dental News
+Letter</i>.)</p>
+
+<p>"A tin plug will answer a very good purpose in
+medium and large cavities for six years. Much
+imposition has been practiced with it, and it is not
+made as malleable as it should and can be. An
+inferior article is manufactured which possesses
+brilliancy and resembles silver. This is often
+passed off for silver foil. No harm comes from
+this deception except the loss of the amount paid
+above the price for tin; but even this inferior tin
+foil is better than silver." ("The Practical Family
+Dentist," Dewitt C. Warner, New York, 1853.)</p>
+
+<p>"Tin made into leaves is employed as a stopping
+material; with sufficient experience it can be elaborated
+into the finest lines and cracks, and against
+almost the weakest walls, and teeth are sometimes
+lost with gold that might have been well preserved
+with tin. I saw an effective tin stopping in a tooth
+of Cramer's, the celebrated musical composer,
+which had been placed there thirty-five years ago<span class='pagenum'><a name="Page_18" id="Page_18">[18]</a></span>
+by Talma, of Paris." ("The Odontalgist," by J.
+Paterson Clark, London, 1854.)</p>
+
+<p>Refer to what the same author said in 1836.</p>
+
+<p>"Tin is the best substitute for gold, and can often
+be used in badly shaped cavities where gold cannot."
+(Prof. Harris, 1854.)</p>
+
+<p>"Tin is better than any mixture of metals for
+filling teeth." (Professor Tomes, London, 1859.)</p>
+
+<p>In 1860 a writer said that "such a change may
+take place in the mouth as to destroy tin fillings
+which had been useful for years, and that tin was
+not entirely reliable in any case; it must not be
+used in a tooth where there is another metal, nor be
+put in the bottom of a cavity and covered with
+gold, for the tin will yield, and when fluids come in
+contact with the metals, chemical action is induced,
+and the tin is oxidized. Similar fillings in the same
+mouth may not save the teeth equally well. Filling
+is predicated on the nature of decay, for only
+on correct diagnosis can a proper filling-material
+be selected."</p>
+
+<p>Reviewing the foregoing statement, we believe
+that a change may take place in the mouth which
+will destroy gold fillings (or the tooth-structure
+around them) much oftener than those of tin. It
+is now every-day practice to put tin into the same
+tooth with another metal; if the bottom of a cavity<span class='pagenum'><a name="Page_19" id="Page_19">[19]</a></span>
+is filled with tin properly packed, it will not yield
+when completed with gold, and if the gold is tight,
+the oral fluids cannot come in contact with both
+metals and produce chemical action or oxidation;
+similar fillings of gold in the same mouth do not
+save the teeth equally well. Should we expect
+more of tin in this respect, or discard it because it
+is not always better than gold?</p>
+
+<p>In Article V of the "New Departure Creed,"
+Dr. Flagg says, "Skillful and scrupulous dentists
+fill with tin covered with gold, thereby preventing
+decay, pulpitis, death of the pulp, and abscess, and
+thus save the teeth."</p>
+
+<p>In 1862 Mr. Hockley, of London, mentions tin
+for filling, and the same year Dr. Zeitman, of Germany,
+recommended it as a substitute for gold, particularly
+for poor people.</p>
+
+<p>"Is tin foil poisonous? If not, why are our
+brethren so reluctant to use it? Is it nauseous?
+If not, why not employ it? Will it not preserve
+the teeth when properly used? Then why not
+encourage the use of it? Does its name signify
+one too common in the eyes of the people, on
+account of its daily use in the tin shops, or do patients
+murmur when the fee is announced, because
+it is nothing but tin? Is it not better than amalgam,
+although the patient may believe it less<span class='pagenum'><a name="Page_20" id="Page_20">[20]</a></span>
+costly? Eleven good plugs, twenty-nine years old,
+in one mouth demonstrates that tin will last as
+long as gold in many cases." (F. A. Brewer,
+<i>Dental Cosmos</i>, 1863.)</p>
+
+<p>"So much tin foil is used for personal and domestic
+purposes that the following is important:
+Ordinary tin foil by chemical analysis contained
+88.93 per cent. of lead; embossed foil, 76.57 per
+cent.; tea foil, 88.66 per cent.; that which was sold
+for the pure article, 34.62 per cent. Tin foil of
+above kind is made by inclosing an ingot of lead
+between two ingots of tin, and rolling them out
+into foil, thus having the tin on the outside of the
+lead." (Dr. J. H. Baldock, <i>Dental Cosmos</i>, 1867.)</p>
+
+<p>The author used tin foil for filling the teeth of
+some of his fellow-students at the Ohio College of
+Dental Surgery in 1867.</p>
+
+<p>"Amalgam should never be used in teeth which
+can be filled with tin, and most of them can be."
+(Dr. H. M. Brooker, Montreal, 1870.)</p>
+
+<p>"I have used tin extensively, and found it more
+satisfactory than amalgam. Dentists ignore tin,
+because it is easier to use amalgam, less trouble.
+This is not right. If your preceptor has told you
+that amalgam is as good as tin, and he thinks so,
+let him write an article in its defense. Not one
+dentist in ten who has come into the profession<span class='pagenum'><a name="Page_21" id="Page_21">[21]</a></span>
+within the last ten years knows how to make a tin
+filling, and only a few of the older ones know how
+to make a <i>good</i> one." (Dr. H. S. Chase, <i>Missouri
+Dental Journal</i>, 1870.)</p>
+
+<p>"Among the best operators a more general use
+of tin would produce advantageous results, while
+among those whose operations in gold are not generally
+successful an almost exclusive use of tin
+would bring about a corresponding quantum of
+success to themselves and patients, as against repeated
+failures with gold. The same degree of
+endeavor which lacked success with gold, if applied
+to tin would produce good results and save teeth.
+A golden shower of ducats realized for gold finds
+enthusiastic admirers, but a dull gray shower for tin
+work is not so admirable, even though many of the
+teeth were no better for the gold as gold, nor so
+well off in the ultimate as with tin." (Dr. E. W.
+Foster, <i>Dental Cosmos</i>, 1873.)</p>
+
+<p>In 1873 Dr. Royal Varney said, "I am heartily
+in favor of tin; it is too much neglected by our first-class
+operators."</p>
+
+<p>"Tin stops the ends of the tubuli and interglobular
+spaces which are formed in the teeth of excessive
+vascular organization; if more teeth were filled
+with tin, and a smaller number with futile attempts<span class='pagenum'><a name="Page_22" id="Page_22">[22]</a></span>
+with gold, people would be more benefited." (Dr.
+Castle, <i>Dental Cosmos</i>, 1873.)</p>
+
+<p>"If cavities in teeth out of the mouth are well
+filled with tin, and put into ink for three days, no
+discoloration of the tooth (when split open) can be
+seen." (W. E. Driscoll, <i>Dental Cosmos</i>, 1874.)</p>
+
+<p>"Tin makes an hermetical filling, and resists the
+disintegrating action of the fluids of the mouth.
+If an operator can preserve teeth for fifteen dollars
+with tin, which would cost fifty dollars with gold,
+ought he not to do so? Upon examination of the
+cavities from which oxidized plugs have been removed,
+these oxids will be found to have had a
+reflex effect upon the dentin; the walls and floors
+will be discolored and thoroughly indurated, and
+to a great degree devoid of sensitiveness, although
+they were sensitive when filled. Tin is valuable in
+case of youth, nervousness, impatience, high vitality
+of dentin, low calcification, and low pecuniosity."
+(Dr. H. Gerhart, <i>Pennsylvania Journal of
+Dental Science</i>, 1875.)</p>
+
+<p>"Tin Foil for Filling Teeth." Essay by Dr. H. L.
+Ambler, read before the Ohio State Dental Society.
+(<i>Dental Register of the West</i>, 1875.)</p>
+
+<p>"Some say that if tin is the material the cavity
+must be filled with, that it must be filled entirely<span class='pagenum'><a name="Page_23" id="Page_23">[23]</a></span>
+with it, but advanced teachings show differently."
+(Dr. D. D. Smith, <i>Dental Cosmos</i>, October, 1878.)</p>
+
+<p>"Frail teeth can be saved better with tin than
+with gold. I never saw a devitalized pulp under a
+tin filling." (Dr. Dixon, <i>Dental Cosmos</i>, May,
+1880.)</p>
+
+<p>"Tin may be used as a base for proximate fillings
+in bicuspids or molars, in third molars, in children's
+permanent molars, in the temporary teeth, and in
+any cavity where the filling is not conspicuous."
+(Dr. A. W. Harlan, <i>Independent Practitioner</i>, 1884.)</p>
+
+<p>"Tin in blocks, mats, and tapes is used like non-cohesive
+gold foil, but absence of cohesion prevents
+the pieces from keeping their place as well as the
+gold." ("American System of Dentistry," 1887.)</p>
+
+<p>This is virtually saying that there is cohesion of
+non-cohesive gold, and that for this reason it keeps
+its place better than tin. It has always been supposed
+that there was no cohesion of layers of non-cohesive
+gold, and as the tin is used on the non-cohesive
+plan, therefore one keeps its place as well
+as the other. We claim that generally in starting
+a filling, tin will keep its place better than cohesive
+or non-cohesive gold, because it combines some of
+the cohesiveness of the former with the adaptability
+of the latter.</p>
+
+<p>"Tin will save teeth in many cases as well or<span class='pagenum'><a name="Page_24" id="Page_24">[24]</a></span>
+better than gold. Put a mat of tin at the cervical
+wall of proximate cavities in molars and bicuspids,
+and it makes a good filling which has a therapeutic
+effect on tooth-structure that prevents the recurrence
+of caries, probably because the infiltration of
+tin oxid into the tubuli is destructive to animal life.
+Where the filling is not exposed to mechanical
+force, there is no material under heavens which will
+preserve the teeth better." (Dr. Beach, <i>Dental
+Cosmos</i>, 1889.)</p>
+
+<p>"I extracted a tooth in which I found a cavity of
+decay which had extended toward a tin filling, but
+stopped before reaching it; on examining the
+tooth-structure between the new cavity and the tin
+filling, it was found to be very hard, indicating
+apparently that there had been some action produced
+by the presence of the tin." (Dr. G. White,
+<i>Dental Cosmos</i>, 1889.)</p>
+
+<p>"Pure tin in form of foil is used as a filling and
+also in connection with non-cohesive gold."
+(Mitchell's "Dental Chemistry," 1890.)</p>
+
+<p>"Tin ranks next to gold as a filling-material."
+(Essig's "Dental Metallurgy," 1893.)</p>
+
+<p>"Tin is good for children's teeth, when gold or
+amalgam is not indicated. It can be used in cavities
+which are so sensitive to thermal changes as to
+render the use of gold or amalgam unwise, but it<span class='pagenum'><a name="Page_25" id="Page_25">[25]</a></span>
+can only be used in cavities with continuous walls,
+and should be introduced in the form of cylinders
+or ropes, with wedge-shaped pluggers having sharp
+deep serrations, thus depending upon the wedging
+or interdigitating process to hold the filling in the
+cavity." ("Operative Technics," Prof. T. E.
+Weeks, 1895.)</p>
+
+<p>"Tin for filling teeth has been almost superseded
+by amalgam, although among the older practitioners
+(those who understand how to manipulate
+it) tin is considered one of the best, if not the very
+best metal known for preserving the teeth from
+caries. In consequence of its lack of the cohesive
+property, it is introduced and retained in a cavity
+upon the wedging principle, the last piece serving
+as a keystone or anchor to the whole filling. Each
+piece should fill a portion of the cavity from the
+bottom to the top, with sufficient tin protruding
+from the cavity to serve for thorough condensation
+of the surface, and the last piece inserted should
+have a retaining cavity to hold it firmly in place.
+The foil is prepared by folding a whole or half-sheet
+and twisting it into a rope, which is then cut into
+suitable lengths for the cavity to be filled."
+(Frank Abbott, "Dental Pathology and Practice,"
+1896.)</p>
+
+<p>"Forty-three years ago, for a young lady fourteen<span class='pagenum'><a name="Page_26" id="Page_26">[26]</a></span>
+years of age, I filled with non-cohesive gold
+all the teeth worth filling with this metal; the rest I
+filled with tin. Three years after that there was
+not a perfect gold filling among the whole number,
+and yet the tin fillings were just as good as when
+made. The explanation as to why the tin fillings
+lasted so much longer than the gold ones was, that
+there must have been something in the tin that had
+an affinity for the teeth and the elements that
+formed the dentin, by which some compound was
+formed, or else it must have been in the adaptation."
+(Dr. H. Gerhart, <i>Dental Cosmos</i>, January,
+1897.)</p>
+
+<hr /><p><span class='pagenum'><a name="Page_27" id="Page_27">[27]</a></span></p>
+<h2>CHAPTER IV.</h2>
+
+<p><span class="smcap">At</span> the World's Columbian Dental Congress,
+held in Chicago, August, 1893, the author presented
+an essay on "Tin Foil for Filling Teeth."</p>
+
+<p>During the discussion of the subject, the following
+opinions were elicited:</p>
+
+<p>Dr. E. T. Darby: "I have always said that tin
+was one of the best filling-materials we have, and
+believe more teeth could be saved with it than with
+gold. I have restored a whole crown with tin, in
+order to show its cohesive properties; the essayist
+has paid a very high and worthy tribute to tin."</p>
+
+<p>Dr. R. R. Freeman: "I have used tin foil for
+twenty-five years, and know that it has therapeutic
+properties, and is one of the best filling-materials,
+not excepting gold."</p>
+
+<p>Madam Tiburtius-Hirschfield: "I heartily indorse
+the use of tin, and have tested its cohesive
+properties by building up crowns."</p>
+
+<p>Dr. A. H. Brockway: "I am a strong believer
+in the use of tin, on account of its adaptability, and
+the facility with which saving fillings can be made
+with it."</p>
+
+<p>Dr. Gordon White: "After having used tin for<span class='pagenum'><a name="Page_28" id="Page_28">[28]</a></span>
+nine years, I claim that it is the best filling-material
+that has been given to our profession."</p>
+
+<p>Dr. C. S. Stockton: "Tin is one of the best
+materials for saving teeth, and we should use it
+more than we do."</p>
+
+<p>Dr. James Truman: "I use tin strictly upon the
+cohesive principle, and would place it in all teeth
+except the anterior ones, but would not hesitate to
+fill these when of a chalky character."</p>
+
+<p>Dr. Corydon Palmer: "For fifty-four years I
+have been a firm advocate of the use of tin, and I
+have a filling in one of my teeth which is forty years
+old."</p>
+
+<p>Dr. William Jarvie: "I rarely fill a cavity with
+gold for children under twelve years of age that I
+want to keep permanently, but use tin, and in five
+or ten years, more or less, it wears out. Still, it
+can easily be renewed, or if all the tin is removed
+we find the dentin hard and firm. The dentist is
+not always doing the best for his patients if he does
+not practice in this way."</p>
+
+<p>Dr. C. E. Francis: "I have proved positively
+that tin foil in good condition is cohesive, and my
+views have been corroborated by dentists and
+chemists."</p>
+
+<p>Dr. James E. Garretson: "Tin foil is cohesive,<span class='pagenum'><a name="Page_29" id="Page_29">[29]</a></span>
+and can be used the same as gold foil, and to an
+extent answers the same purpose."</p>
+
+<p>Dr. C. R. Butler: "Tin is cohesive and makes a
+first-class saving filling."</p>
+
+<p>Dr. W. C. Barrett: "Tin is as cohesive as gold,
+and if everything was blotted out of existence with
+which teeth could be filled, except tin, more teeth
+would be saved."</p>
+
+<p>Dr. L. D. Shepard: "Tin possesses some antiseptic
+properties for the preservation of teeth that
+gold does not."</p>
+
+<p>Dr. W. D. Miller: "I use tin foil in cylinders,
+strips, and ropes, on the non-cohesive plan, but
+admit that it possesses a slight degree of cohesiveness,
+and when necessary can be built up like cohesive
+gold by using deeply serrated pluggers."</p>
+
+<p>Dr. Benjamin Lord says, "It is said that we know
+the world, or learn the world, by comparison. If
+we compare tin foil with gold foil, we find that the
+tin, being softer, works more kindly, and can be
+more readily and with more certainty adapted to
+the walls, the inequalities, and the corners of the
+cavities.</p>
+
+<p>"We find also that tin welds&mdash;mechanically, of
+course&mdash;more surely than soft gold, owing to its
+greater softness; the folds can be interlaced or
+forced into each other, and united with more certainty,<span class='pagenum'><a name="Page_30" id="Page_30">[30]</a></span>
+and with so much security that, after the
+packing and condensing are finished, the mass may
+be cut like molten metal.</p>
+
+<p>"I contend moreover that for contouring the
+filling or restoring the natural shape of the teeth,
+where there are three walls remaining to the cavity,
+tin is fully equal to gold, and in some respects even
+superior; as tin can be secured, where there is very
+little to hold or retain the filling, better than gold,
+owing to the ease and greater certainty of its adaptation
+to the retaining points or edges of the cavity.</p>
+
+<p>"It will be said, however, that tin fillings will
+wear away. The surfaces that are exposed to mastication
+undoubtedly will wear in time; but the filling
+does not become leaky if it has been properly
+packed and condensed, nor will the margins of the
+cavity be attacked by further decay on that account.</p>
+
+<p>"Altogether, I believe that we can make more
+perfect fillings with tin than we can with gold, taking
+all classes of cavities; but it must not be understood
+that it is proposed that tin should ever take
+the place of gold where the circumstances and conditions
+indicate that the latter should be used. Of
+course, the virtue is not in the gold or the tin, but
+in the mechanical perfection of the operation, and
+tin having more plasticity than gold, that perfection
+can be secured with more ease and certainty.<span class='pagenum'><a name="Page_31" id="Page_31">[31]</a></span></p>
+
+<p>"If we compare tin with amalgam, we must certainly
+decide in favor of the former and give it preference;
+as if it is packed and condensed as perfectly
+as may be, we know just what such fillings will do
+every time. We know that there will be no
+changes or leakage of the fillings at the margins;
+whereas, with amalgam, the rule is shrinkage of the
+mass, and consequently the admission of moisture
+around the filling, the result being further decay.
+It is not contended that this is always the result
+with amalgam, but it is the general rule; yet we
+must use amalgam, as there are not a few cases
+where it is the best that we can do; but it is to be
+hoped, and I think it may be said, that as manipulative
+skill advances, amalgam will be less and less
+used. For so-called temporary work, very often I
+prefer tin to gutta-percha, as it makes a much more
+reliable edge and lasts longer, even when placed
+and packed without great care."&mdash;<i>N. Y. Odon. Society
+Proceedings</i>, page 51, 1894.</p>
+
+<p>One of the main reasons which induced the
+writer to begin the use of tin foil (<i>Stannum Foliatum</i>)
+for filling teeth, in 1867, was the fact that
+amalgam filling failures were being presented
+daily. Believing that tin could do no worse, but
+probably would do better, we banished amalgam
+from the office for the succeeding seven years,<span class='pagenum'><a name="Page_32" id="Page_32">[32]</a></span>
+using in the place of it tin, oxychlorid, and gutta-percha.
+Since that time we have seen no good
+reason for abandoning the use of tin, as time has
+proved it worthy of great confidence. There is no
+better dental litmus to distinguish the conservative
+from the progressive dentist.</p>
+
+<p>If we take a retrospective view and consider what
+tin foil was thirty years ago, we do not wonder that
+so many operators failed to make tight, good-wearing
+fillings. As it came from the manufacturer
+it looked fairly bright, but after being exposed
+to the air for a short time it assumed a light
+brassy color, and lost what small amount of integrity
+it originally possessed. This tin was not
+properly refined before beating, or something was
+put on the foil while beating, so that it did not have
+the clean, bright surface and cohesive quality which
+our best foil now has. No. 4 was commonly used,
+but it would cut and crumble in the most provoking
+manner. Fillings were made by using mats,
+cylinders, tapes, and ropes, with hand-pressure, on
+the plan for manipulating non-cohesive gold foil,
+but it was difficult to insert a respectable approximal
+filling.</p>
+
+<p>From the best information obtainable, the writer
+believes that Marcus Bull (the predecessor of
+Abbey) was the first to manufacture and sell tin<span class='pagenum'><a name="Page_33" id="Page_33">[33]</a></span>
+foil in the United States, as he began the manufacture
+of gold foil at Hartford in 1812.</p>
+
+<p>Several years ago a radical change came about in
+the preparation of tin foil, for which the manufacturer
+should have his share of the credit, even if
+the dentist did ask for something better, for the
+quality depends largely upon the kind and condition
+of the tin used and on the method of manufacture.</p>
+
+<p>For making tin foil for filling teeth, the purest
+Banca tin that can be obtained is used. The tin is
+melted in a crucible under a cover of powdered
+charcoal. It is then cast into a bar and rolled to
+the desired thickness, so that if No. 6 foil is to be
+made, a piece one and one-half (1<span class="abv">1</span>&#8260;<span class="blw">2</span>) inches square
+would weigh nine grains. This ribbon is then cut
+into lengths of about four feet, and spread on a
+smooth board slanted, so that the end rests in a vat
+of clean water.</p>
+
+<p>Then apply to the exposed surface of the ribbon
+diluted muriatic acid, and immediately wash with a
+strong solution of ammonia. Turn the ribbon and
+treat the other side in the same way. It is then
+washed and rubbed dry. The object of using the
+acid is to remove stains and whiten the tin, and the
+ammonia is used to neutralize the effect of the acid.</p>
+
+<p>The strips are then cut into pieces one and a half<span class='pagenum'><a name="Page_34" id="Page_34">[34]</a></span>
+inch square, filled into a cutch and beaten to about
+three inches square. It is then removed from the
+cutch and filled into a mold, and further beaten to
+the desired size. When the ragged edges are
+trimmed off, the foil is ready for booking.</p>
+
+<p>It takes skill and experience to beat tin foil, for it
+is not nearly as malleable as gold; up to No. 20 it
+is usually beaten, but higher numbers are prepared
+by rolling. In each case the process is similar to
+that employed in preparing gold foil. The number
+on the book is supposed to indicate the weight
+or thickness of the leaf. On the lower numbers
+the paper of the book leaves its impression.</p>
+
+<p>On weighing sheets of tin foil from different
+manufacturers a remarkable discrepancy was found
+between the number on the book and the number
+of grains in a sheet, viz: Nos. 3, 4, 5, weighed 7 gr.
+each; No. 6, 9 gr.; No. 8, from 9 to 18 gr.; No. 10,
+from 14 to 15 gr.; No. 20, 18 gr. In some instances
+the sheets in the same book varied three grains.
+We submit that it would be largely to the advantage
+of both manufacturer and dentist to have the
+number and the grains correspond. No dentist
+wishes to purchase No. 8 and find that he has No.
+18; no one could sell gold foil under like circumstances.
+Of the different makes tested, White's
+came the nearest to being correct. The extra<span class='pagenum'><a name="Page_35" id="Page_35">[35]</a></span>
+tough foil which can now be obtained is chemically
+pure, and with it we can begin at the base of any
+cavity, and with mallet or hand force produce a
+filling which will be one compact mass, so that it
+can be cut and filed; yet in finishing, it will not bear
+so severe treatment as cohesive gold. Always
+handle tin foil with clean pliers, never with the
+fingers; and prepare only what is needed for each
+case, keeping the remainder in the book placed in
+the envelope in which it is sold, otherwise extraneous
+matter collects upon it, and it will oxidize
+<i>slightly</i> when exposed to the air for a <i>great</i> length
+of time.</p>
+
+<p>Before using tin foil, a few prefer to thoroughly
+crumple it in the hands or napkin, under the impression
+that they thus make it more pliable and
+easier to manipulate.</p>
+
+<p>A piece of blue litmus paper moistened and
+moved over a sheet of tin foil will occasionally give
+an acid reaction, probably owing to the acid with
+which it is cleaned before beating not having been
+thoroughly removed. Foil held under the surface
+of distilled water and boiled for five minutes, then
+left until the water is cold, removed and dried,
+shows it has been annealed, which makes it work
+easily, but not as hard a filling can be made from it
+as before boiling.<span class='pagenum'><a name="Page_36" id="Page_36">[36]</a></span></p>
+
+<p>In selecting and using this material for filling,
+we are able fully to protect the cavity; and if we
+understand the material, and how to manipulate it,
+we will surely succeed. This statement demands
+serious attention, and appeals to every one who is
+anxious to practice for the best interests of his
+patients; then let us make a thorough study of the
+merits of the method and material.</p>
+
+<p>Until recently, the term cohesion had but one
+special meaning to dentists, and that as applied to
+gold for filling teeth; being understood as the property
+by which layers of this metal could be united
+without force so as to be inseparable. The writer
+claims that good tin foil in proper condition is
+cohesive when force is applied, and can be used for
+filling teeth in the same manner in which cohesive
+gold foil is used. This claim has been confirmed
+by several dentists, as noted in another part of this
+volume.</p>
+
+<p>Cohesion is the power to resist separation, and
+it acts at insensible distances. The integral particles
+of a body are held together by cohesion, the
+constituent parts are united by affinity.</p>
+
+<p>The attraction between atoms of pure tin represents
+cohesion. Marble is composed of lime and
+carbonic acid, which are united and held together
+by affinity.<span class='pagenum'><a name="Page_37" id="Page_37">[37]</a></span></p>
+
+<p>The condition which obtains in the tin may be
+called cohesion, adhesion, welding, or interdigitation,
+but the fact remains that layers of tin foil can
+be driven together into a solid mass, making a
+tight filling with less malleting than is required for
+gold; if it is overmalleted, the receiving surface is
+injured.</p>
+
+<p>On account of its pliability it is easily adapted
+to the walls and margins, and a perfect fit is made,
+thus preventing capillary action and preventing
+further caries. Of all the metals used for filling
+it is the best tooth-preserver and the most compatible
+with tooth-substance, and the facility with
+which a saving filling can be made largely commends
+it.</p>
+
+<p>Tin has great possibilities, and has already
+gained a high position as a filling-material. Upon
+the knowledge we possess of the possibilities and
+limitations of tin as a filling-material, and our ability
+to apply that knowledge, will largely depend
+our success in preserving teeth.</p>
+
+<p>It is a good material for filling many cavities in
+the temporary teeth, and children will bear having
+it used, because it can be placed quickly, and but
+little force is required to condense one or two layers
+of No. 10 foil. The dentin in young teeth has a
+large proportion of organic material, for which<span class='pagenum'><a name="Page_38" id="Page_38">[38]</a></span>
+reason, if caries takes place, many believe it is
+hastened by thermal changes. Gold fillings in
+such teeth might prevent complete calcification, on
+account of the gold being so good a conductor; but
+if tin is used, there is much more probability of calcification
+taking place, because of its low conductivity
+and its therapeutic influence. It does not
+change its shape after being packed into a cavity.
+Under tin, teeth are calcified and saved by the
+deposit of lime-salts from the contents of the dentinal
+tubuli. This is termed progressive calcification.</p>
+
+<p>Like other organs of the human body, the teeth
+are more or less subject to constitutional change.
+The condition in which we find tooth-structure
+which needs repairing or restoring should be a sure
+indicator to us in choosing a filling-material. Up
+to the age of fourteen, and sometimes later, we find
+many teeth which are quite chalky. In some
+mouths also, at this period, the fluids are in such a
+condition that oxychlorid and oxyphosphate do not
+last long; for some reason amalgam soon fails,
+while gutta-percha is quickly worn out on an occlusal
+surface. In all such cases we recommend
+tin, even in the anterior teeth, for as the patient
+advances in years the tooth-structure usually becomes
+more dense, so that, if desirable, the fillings<span class='pagenum'><a name="Page_39" id="Page_39">[39]</a></span>
+can be removed, and good saving operations can be
+made with gold. By treating cases in this manner
+very little, if any, tooth-structure is lost.</p>
+
+<p>The teeth of the inhabitants of Mexico and
+Guatemala are characteristic of their nervous and
+nervo-lymphatic temperaments; children ten years
+of age often have twenty-eight permanent teeth,
+and they are generally soft or chalky, but our
+dentists there report good success in saving them
+with tin.</p>
+
+<p>In filling this class of teeth, we should be very
+careful not to use force enough to injure the cavity-margin,
+for if this occurs, a leaky filling will probably
+be the result. Still, we have seen some cases
+where <i>slight</i> imperfections at the margin, which
+occurred at the time of the filling or afterward, did
+no harm, because the deposit of tin oxid filled up
+the ends of the tubuli, thus preventing caries. We
+believe that this bar to the progress of caries is set
+up more frequently when tin is used than with any
+other metal under like conditions.</p>
+
+<hr /><p><span class='pagenum'><a name="Page_40" id="Page_40">[40]</a></span></p>
+<h2>CHAPTER V.</h2>
+
+<p><span class="smcap">In</span> some mouths tin does not discolor, but retains
+a clean, unpolished tin color, yet when there is a
+sesquioxid of the metal formed, fillings present a
+grayish appearance. In the same mouth some
+fillings will be discolored, while others are not. As
+a general rule, proximal fillings are most liable to
+show discoloration. Perhaps one reason is that on
+occlusal and buccal surfaces they are subject to
+more friction from mastication, movements of the
+cheeks, and the use of the brush.</p>
+
+<p>We have seen a large number of fillings which
+were not blackened, yet were saving the teeth perfectly,
+thus proving to a certainty that blackening
+of tin in the tooth-cavity is not absolutely essential
+in order to obtain its salvatory effects as a filling-material.</p>
+
+<p>Where there is considerable decomposition of
+food which produces sulfuretted hydrogen, the
+sulfid of tin may be formed on and around the
+fillings; it is of a yellowish or brownish color, and
+as an antiseptic is in such cases desirable. To offset
+the discoloration, we find that the sulfid is insoluble,
+and fills the ends of the tubuli, thus lending its
+aid in preventing further caries. A sulfid is a combination<span class='pagenum'><a name="Page_41" id="Page_41">[41]</a></span>
+of sulfur with a metal or other body. A
+tin solution acted on by sulfuretted hydrogen
+(H<sub>2</sub>S) produces a dark-brown precipitate (SnS),
+stannous salt, which is soluble in ammonium sulfid
+(NH<sub>4</sub>)<sub>2</sub>S<sub>2</sub>; this being precipitated, gives (SnS<sub>2</sub>)
+stannic salt, which is yellow. Brown precipitates
+are formed by both hydrogen sulfid and ammonium
+sulfid, in stannous solutions. Yellow precipitates
+are formed by hydrogen sulfid and ammonium
+sulfid in stannic solutions. The yellow shade is
+very seldom seen on tin fillings; the dark brown is
+more common.</p>
+
+<p>An oxid is a combination of oxygen with a metal
+or base destitute of an acid. In oxidation the oxygen
+that enters into combination is not sufficient to
+form an acid. The protoxid of tin (SnO) is black,
+and can be obtained from chlorid of tin, or by <i>long</i>
+exposure of tin to the atmosphere. The oxygen in
+the saliva helps to blacken the tin, and the metallic
+oxid penetrates the dentin more or less, acting as
+a protection, because it is insoluble. Oxygen is
+the only element which forms compounds with all
+others, and is the type of electro-negative bodies;
+it combines with all metals, therefore with tin, and
+in many cases only the metal is discolored, and not
+the tooth. Steam boilers are made tight by oxidation.<span class='pagenum'><a name="Page_42" id="Page_42">[42]</a></span></p>
+
+<p>Where there is complete oxidation, the tooth is
+blackened to but a very slight depth, and the oxid
+fills the ends of the tubuli, thus affording an additional
+barrier to the entrance of caries. The filling
+itself will prevent caries, but oxidation acts as an
+assistant.</p>
+
+<p>"In the mouth, a suboxid is more likely to be
+formed than a protoxid, but both are black; sulfur
+and oxygen are capable of acting on tin under
+favorable circumstances, such as warmth, moisture,
+full contact, condensation of elements, and their
+nascent conditions; the first three are always present
+in the mouth. The protosulfuret of tin is
+black." (Dr. George Watt.) Others give the
+color as bluish-gray, nearly black.</p>
+
+<p>Experiments show that slight galvanic currents
+exist between fillings of dissimilar metals in the
+mouth, and practical experience demonstrates that
+these currents occasionally produce serious results.</p>
+
+<p>Direct galvanic currents do not decompose normal
+teeth by true electrolysis, but acids resulting
+from decomposition of food and fluids react upon
+the lime constituents of the teeth and promote secondary
+caries.</p>
+
+<p>When two metals are so situated in the mouth
+that the mucous membrane forms a connecting
+conductor and the fluids are capable of acting on<span class='pagenum'><a name="Page_43" id="Page_43">[43]</a></span>
+one metal, galvanic action is established sufficient
+to decompose any of the binary compounds contained
+in these fluids; the liberated nitrogen and
+hydrogen form ammonia, which being exposed to
+the action of oxygen is decomposed and nitric oxid
+formed, resulting in nitric acid. We also have in
+the mouth air, moisture, and decomposing nitrogenous
+food to assist in the production of nitric
+acid.</p>
+
+<p>"Galvanic action is more likely to develop hydrochloric
+acid, for the chlorids of sodium and potassium
+are present in the normal saliva and mucus,
+and when decomposed their chlorin unites with the
+hydrogen derived from the water of the saliva."
+(Dr. George Watt.)</p>
+
+<p>The fact should also be noted that both nitric and
+hydrochloric acids are administered as medicine,
+and often assist in producing decay.</p>
+
+<p>When there is a battery formed in a mouth containing
+tin fillings and gold fillings, and the fluids
+of the mouth are the exciting media, tin will be
+the positive element and gold the negative element;
+thus when they form the voltaic pair, the tin becomes
+coated or oxidized and the current practically
+ceases.</p>
+
+<p>There is more or less therapeutical and chemical
+action in cavities filled with tin, and its compatibility<span class='pagenum'><a name="Page_44" id="Page_44">[44]</a></span>
+and prophylactic behavior as a filling-material
+depends partly upon the chemical action which
+occurs.</p>
+
+<p>Some dentists fill sensitive cavities with tin, in
+order to secure gentle galvanic action, which they
+believe to be therapeutic, solidifying the tooth-structure.</p>
+
+<p>"Tin possesses antiseptic properties which do not
+pertain to gold for arresting decay in frail teeth; it
+not only arrests caries mechanically, but in chalky
+(imperfect) structure acts as an antacid element in
+arresting the galvanic current set up between the
+tooth-structure and filling-material." (Dr. S. B.
+Palmer.) If the metal is acted on, the tooth is
+comparatively safe; if the reverse, it is more or less
+destroyed. The galvanic taste can be produced by
+placing a piece of silver on the tongue and a steel
+pen or piece of zinc under it; then bring the edges
+of the two pieces together for a short time, rinse
+the saliva around in the mouth, and the peculiar
+flavor will be detected.</p>
+
+<p>"In 1820 attention was called to the injurious
+effects of the galvanic current on the teeth, and
+dentists were advised never to use tin and amalgam
+in the same mouth.</p>
+
+<p>"A constant galvanic action is kept up in the
+mouth when more than one kind of metal is used<span class='pagenum'><a name="Page_45" id="Page_45">[45]</a></span>
+in filling teeth, and galvanism is often the cause of
+extensive injury to the teeth. The most remarkable
+case I ever saw was that of a lady for whom
+I filled several teeth with tin. After a time decay
+took place around some of the fillings. I removed
+them and began to refill, but there was so much
+pain I could not proceed. I found that by holding
+a steel plugger an inch from the tooth I could give
+her a violent galvanic shock. I observed that the
+exhalation of the breath increased the evolution of
+galvanism." (Dr. L. Mackall, <i>American Journal
+of Dental Science</i>, 1839.)</p>
+
+<p>"When a faulty tooth in the upper jaw had been
+stopped from its side with tin, the interstice between
+it and the adjoining tooth being quite inconsiderable,
+while the upper surface of a tooth not
+immediately beneath it in the lower jaw was
+stopped with the same metal, I have known a galvanic
+shock regularly communicated from one
+tooth to the other when by the movement of jaws
+or cheeks they were brought near together." (Dr.
+E. Parmly, <i>American Journal of Dental Science</i>,
+1839.)</p>
+
+<p>"An interesting debate here sprung up on the
+action where two metals are used in one filling,
+such as gold and tin, the saliva acting as a medium,
+and where the baser metal is oxidized by exhalents<span class='pagenum'><a name="Page_46" id="Page_46">[46]</a></span>
+and by imbibition through the bony tooth-structure."
+(Pennsylvania Society of Dental Surgeons,
+1848.)</p>
+
+<p>"A patient came to me and complained of pain
+in the teeth. Upon examination I found an amalgam
+filling next to one of tin. With a file I
+made a V-shaped separation, when they experienced
+immediate relief from pain." (Dr. Nevill,
+<i>American Journal of Dental Science</i>, 1867.)</p>
+
+<p>In regard to the decay of teeth being dependent
+on galvanic action present in the mouth, Dr. Chase,
+in 1880, claimed that a tooth filled with gold would
+necessarily become carious again at the margin of
+the cavity, wherever the acid secretions constantly
+bathe the filling and tooth-substance. A tooth
+filled with amalgam succumbs to this electro-chemical
+process less rapidly, while one filled with tin
+still longer escapes destruction. The comparative
+rapidity with which teeth filled with gold, amalgam,
+or tin, are destroyed is expressed by the numbers
+100, 67, 50. He prepared pieces of ivory of equal
+shape and size, bored a hole in each, and filled them.
+After they had been exposed to the action of an
+acid for one week, they had decreased in weight,&mdash;viz,
+piece filled with gold, 0.06; amalgam, 0.04;
+tin, 0.03.</p>
+
+<p>"With tin and gold, some have the superstition<span class='pagenum'><a name="Page_47" id="Page_47">[47]</a></span>
+that the electricity attendant upon such a filling will
+in some way be injurious to the tooth; it matters
+not which is on the outside, when rolled and used as
+non-cohesive cylinders each appears. We say that
+neither experimentally, theoretically, nor practically
+can any good or bad result be expected from
+the electrical action of a tin-gold filling on tooth-bone,
+and neither will the pulp be disturbed."
+(Dr. W. D. Miller, <i>Independent Practitioner</i>, August,
+1884.)</p>
+
+<p>"When the bottom of a cavity is filled with tin
+which is tightly (completely) covered with gold,
+there is <i>practically</i> no galvanic action and there is
+no current generated by contact of tin and gold,&mdash;<i>i.e.</i>,
+no current leaves the filling to affect the dentin.
+That portion of tin which forms the base is more
+positive than a full tin filling would be. The effect
+is to cause the surface exposed to dentin to oxidize
+more than tin would do alone; in that there is a
+benefit. In very porous dentin there is enough
+moisture to oxidize the tin, by reason of the current
+set up by the gold." (Dr. S. B. Palmer.)</p>
+
+<p>Electricity generated by heat is called thermo-electricity.
+If a cavity with continuous walls is
+half filled with tin and completed with gold, or half
+filled with silver and completed with gold, and the
+junctions of the metal are at 20<span class="abv">1</span>&#8260;<span class="blw">2</span>&deg; C. and 19<span class="abv">1</span>&#8260;<span class="blw">2</span>&deg; C.,<span class='pagenum'><a name="Page_48" id="Page_48">[48]</a></span>
+if the electrical action between the tin and gold be
+1.1, the action between the silver and gold will be
+1.8, thus showing the action in silver and gold to be
+nearly two-thirds more than in the tin and gold, a
+deduction which favors the tin and gold.</p>
+
+<p>Rubbing two different substances together is a
+common method of producing an electric charge.
+Is there not more electricity generated during mastication
+on metal fillings than when the jaws are at
+rest? Friction brings into close contact numerous
+particles of two bodies, and perhaps the electrical
+action going on more or less all the time through
+gold fillings (especially when other metals are in
+the mouth) accounts for a powdered condition of
+the dentin which is sometimes found under cohesive
+gold fillings, but not under tin.</p>
+
+<hr /><p><span class='pagenum'><a name="Page_49" id="Page_49">[49]</a></span></p>
+<h2>CHAPTER VI.</h2>
+
+<p><span class="smcap">White</span> caries, the most formidable variety
+known, may be produced by nitric acid, and in
+these cases all the components of the tooth are
+acted upon and disintegrated as far as the action
+extends. In proximal cavities attacked by this
+kind of caries, separate freely on the lingual side,
+and fill with tin. When such fillings have been removed
+the dentin has been found somewhat discolored
+and greatly solidified as compared to its
+former condition; this solidification or calcification
+is more frequent under tin than gold, which is
+partly due to the tin as a poor conductor of heat.
+Nature will not restore the lost part, but will do the
+next best thing&mdash;solidify the dentin. In some
+cases, under tin, the pulp gradually recedes, and
+the pulp-cavity is obliterated by secondary dentin.
+In other cases the pulps had partly calcified under
+tin. It has been known for years that tin would be
+tolerated in large cavities very near the pulp without
+causing any trouble, and one reason for this is
+its low conducting power. Attention is called to
+the fact that gold is nearly four times as good a
+conductor of heat as tin, and more than six times
+as good a conductor of electricity. Where tin fillings<span class='pagenum'><a name="Page_50" id="Page_50">[50]</a></span>
+are subject to a large amount of attrition, they
+wear away sooner or later, but this is not such a
+great detriment, for they can easily be repaired or
+replaced, and owing to the concave form produced
+by wear the patient is liable to know when a large
+amount has been worn away. That portion against
+the wall of the cavity is the last removed by wear,
+so that further caries is prevented so long as there
+is any reasonable amount of tin left. If at this time
+the tooth has become sufficiently solidified, proper
+anchorage can be cut in the tin or tooth, one or
+both, as judgment dictates, and the filling completed
+with gold. A tin filling, confined by four
+rather frail walls, may condense upon itself, but it is
+so soft and adaptable that the force which condenses
+it continually secures the readaptation at
+the margin; thus there will be no leakage or caries
+for years. Owing to its softness and pliability, it
+may be driven into or onto the tubuli to completely
+close them from outside moisture, and with a hand
+burnisher the tin can be made to take such a hold
+on dry, rough tubuli that a cutting instrument is
+necessary to remove all traces of it.</p>
+
+<p>Tin foil has been found in the market that under
+a magnifying glass showed innumerable tiny black
+specks, which, upon being touched with an instrument,
+crumbled away, leaving a hole through the<span class='pagenum'><a name="Page_51" id="Page_51">[51]</a></span>
+foil. More than likely, some of the failures can be
+attributed to the use of such foil. Good tough foil,
+well condensed by hand or mallet force, stays
+against the walls of a cavity and makes a tight filling,
+and ought to be called as near perfect as any
+filling, because it preserves the tooth, and gives a
+surface which will wear from five to twenty years,
+depending upon the size and location of the cavity
+and tooth-structure. Buccal cavities in the first
+permanent molars, and lingual cavities in the superior
+incisors, filled for children from six to eight
+years of age, are still in good condition after a
+period of twenty years. Perhaps the limit is
+reached in the following cases, all in the mouths of
+<i>dentists</i>: One filling forty years old; one forty-two;
+four on the occlusal surface, fifty; in the latter case
+gold had been used in other cavities and had failed
+several times. Lingual cavities in molars and
+bicuspids can be perfectly preserved with tin.
+Tapes of No. 10 foil, from one to three thicknesses,
+can be welded together and will cohere as well or
+better than semi-cohesive gold foil, and it can be
+manipulated more rapidly; therefore, if desirable,
+any degree of contour can be produced, but the
+contour will not have the hardness or strength of
+gold, so in many cases it would not be practicable<span class='pagenum'><a name="Page_52" id="Page_52">[52]</a></span>
+to make extensive contours with tin, owing to its
+physical characteristics.</p>
+
+<p>No. 10 will answer for all cases, and it is not as
+liable to be torn or cut by the plugger as a lower
+number, but one need not be restricted to it, as
+good fillings can be made with Nos. 4, 6, or 8.
+More teeth can be saved with tin than with any
+other metal or metals, and the average dentist will
+do better with tin than with gold. It is invaluable
+when the patient is limited for time or means, and
+also for filling the first permanent molars, where we
+so often find poor calcification of tooth-structure.
+In cases of orthodontia, where caries has attacked
+a large number of teeth, it is well to fill with tin,
+and await further developments as to irregularity
+and caries.</p>
+
+<p>If cavities are of a good general retaining form,
+that will be sufficient to hold the filling in place;
+but if not, then cut slight opposing angles, grooves,
+or pits. Cavities are generally prepared the same
+as for gold, except where there is a great deal of
+force brought upon the filling; then the grooves or
+pits may be a little larger; still, many cavities can be
+well filled with less excavating than required for
+gold, and proximal cavities in bicuspids and
+molars, where there is sufficient space, can be filled
+without removing the occlusal surface, and here<span class='pagenum'><a name="Page_53" id="Page_53">[53]</a></span>
+especially should the cavities be cut square into the
+teeth, so as not to leave a feather edge of tin when
+the filling is finished, as that would invite further
+caries and prove an obstruction to cleansing the
+filling with floss.</p>
+
+<p>In proximal cavities involving the occlusal surface,
+cut the cervical portion down to a strong
+square base, with a slight pit, undercut, or angle, at
+the buccal and lingual corners; where there is sufficient
+material, a slight groove across the base, far
+enough from the margin so that it will not be
+broken out, can be made in place of the pit, undercut,
+or angle; then cut a groove in the buccal and
+lingual side (one or both, according to the amount
+of material there is to work upon), extending from
+the base to the occlusal surface; in most of these
+cases the occlusal grooves or pits would have to be
+excavated on account of caries; thus there would
+be additional opportunity for anchorage. In place
+of the grooves the cavity may be of the dovetail
+form. In nearly all proximal cavities in bicuspids
+and molars, some form of metal shield, or matrix, is
+of great advantage, as they prevent the tin from
+crushing or sliding out. By driving the tin firmly
+against the metal, a well-condensed surface is secured;
+and as the metal yields a little, we can with a
+bevel or thin plugger force the tin slightly between<span class='pagenum'><a name="Page_54" id="Page_54">[54]</a></span>
+the metal and the margin of the cavity, thus making
+sure of a tight filling, with plenty of material to
+finish well. After removing the metal, condense
+with thin burnishers and complete the finish the
+same as for gold. Where no shield or matrix is
+used, or where it is used and removed before completing
+the filling, it is often desirable to trim the
+cervical border, for in either case there is more
+light and room to work when only a portion of the
+cavity has been filled. Tin cuts so much easier
+than gold, it is more readily trimmed down level
+with all cervical margins.</p>
+
+<p>Be sure that all margins are made perfect as the
+work progresses, and if the cavity is deep and a
+wide shield shuts out the light, then use a narrow
+one, which can be moved toward the occlusal surface
+from time to time.</p>
+
+<p>In filling the anterior teeth when the labial wall
+is gone, and the lingual wall intact or nearly so,
+use a piece of thin metal three-quarters of an inch
+long and wide enough to cover the cavity in the
+tooth to be filled, insert it between the teeth, and
+bend the lingual end over the cavity; the labial end
+is bent out of the way over the labial surface of the
+adjoining tooth, as shown in <a href="#Fig_4">Fig. 4</a>. When the
+labial wall is intact or nearly so, access to the cavity
+should be obtained from the lingual side, and in<span class='pagenum'><a name="Page_55" id="Page_55">[55]</a></span>
+this case the bending of the shield would be reversed,
+as shown in <a href="#Fig_5">Fig. 5</a>. The shield is not absolutely
+essential, but it helps support the tin, and
+also keeps a separation.</p>
+
+<div class="figc"><div class="figl"><a name="Fig_4" id="Fig_4"></a>Fig. 4.
+<img src="images/004.png" width="155" height="124" alt="" title="" />
+</div>
+
+<div class="figr"><a name="Fig_5" id="Fig_5"></a>Fig. 5.
+<img src="images/005.png" width="151" height="124" alt="" title="" />
+</div></div>
+
+<p class="clr">It is preferable to save the labial wall and line it
+with (say) five layers of No. 4 semi-cohesive gold
+folded into a mat and extended to the outer edge
+of the cavity; this gives the tooth a lighter shade,
+and bicuspids or molars can be filled in the same
+manner. Cases are on record where incisors with
+translucent labial walls, filled by this method, have
+lasted from twenty-three to thirty-seven years.</p>
+
+<hr /><p><span class='pagenum'><a name="Page_56" id="Page_56">[56]</a></span></p>
+<h2>CHAPTER VII.</h2>
+
+<p><span class="smcap">For</span> the last ten years the writer has been using
+tin at the cervical margin of proximal cavities in
+bicuspids and molars, especially in deep cavities
+(now an accepted practice), and he finds that it
+prevents further caries oftener than any other metal
+or combination of metals he has ever seen used.
+In filling such cavities, adjust the rubber, and use
+a shield or matrix of such form as to just pass beyond
+the cervical margin; this will generally push
+the rubber out of the cavity, but if it does not, then
+form a wedge of wood and force between the metal
+and the adjoining tooth, thus bringing the metal
+against the cervical margin, and if a small film of
+rubber should still remain in the cavity, it may be
+forced out by using any flat burnisher which will
+reach it, or it can be dissolved out with a little chloroform.
+Fill from one-fourth to one-half of the
+cavity with tin, and complete the remainder with
+gold when the tooth is of good structure; this gives
+all the advantages of gold for an occlusal surface.</p>
+
+<p>Before beginning with the gold, have the tin
+solid and square across the cavity, and the rest of
+the cavity a good retaining form, the same as for
+gold filling; then begin with a strip of gold slightly<span class='pagenum'><a name="Page_57" id="Page_57">[57]</a></span>
+annealed and mallet it into the tin, but do not place
+too great reliance upon the connection of the
+metals to keep the filling in place.</p>
+
+<p>On the same plan, proximal cavities in the anterior
+teeth can be filled, and also buccal cavities in
+molars, especially where they extend to the occlusal
+surface. The cervical margin should be well covered
+with tin thoroughly condensed, thus securing
+perfect adaptation, and a solid base for the gold
+with which the filling is to be completed. Time
+has fully demonstrated that the cervical margin is
+most liable to caries, and here the conservative and
+preservative qualities of tin make it specially applicable.</p>
+
+<p>"Electrolysis demonstrates to us that no single
+metal can be decomposed, but when gold and tin
+are used in the above manner they are united at
+the line of contact by electrolysis. The surface of
+both metals is exposed to the fluids of the mouth,
+and the oxid of tin is deposited on the tin, by reason
+of the current set up by the gold; thus some atoms
+of tin are dissolved and firmly attached to the gold,
+but the tin does not penetrate the gold to any great
+extent." (Dr. S. B. Palmer.)</p>
+
+<p>This connection of the metals assists in holding
+the filling in place, but it is more likely to break
+apart than if it was all gold. After electrolysis has<span class='pagenum'><a name="Page_58" id="Page_58">[58]</a></span>
+taken place at the junction, it requires a cutting
+instrument to completely separate the tin and gold.</p>
+
+<p>For filling by hand pressure, use instruments
+with square ends and sides, medium serrations, and
+of any form or size which will best reach the cavity.</p>
+
+<p>For filling with the hand mallet, use instruments
+with medium serrations, and a steady medium blow
+with a four-ounce mallet; in force of blow we are
+guided by thickness of tin, size of plugger, and
+depth of serrations, strength of cavity-walls and
+margins, the same as in using gold. The majority
+of medium serrated hand mallet pluggers will work
+well on No. 10 tin of one, two, or three thicknesses.
+If the tin shows any tendency to slide, use a more
+deeply serrated plugger. The electro-magnetic,
+and mechanical (engine) mallet do not seem to
+work tin as well as the hand mallet or hand force, as
+the tendency of such numerous and rapid blows is
+to chop up the tin and prevent the making of a solid
+mass, and also injure the receiving surface of the
+filling. In using any kind of force, <i>always</i> aim to
+carry the material to place before delivering the
+pressure, or blow.</p>
+
+<p>In order to obtain the best results, there must be
+absolute dryness, and care must be exercised, not
+thinking that because it is <i>tin</i> it will be all right.
+Skill is required to make good tin fillings, as well<span class='pagenum'><a name="Page_59" id="Page_59">[59]</a></span>
+as when making good gold fillings. Always use
+tapes narrower than the orifice of the cavity; they
+are preferable to rolls or ropes. After a few trials it
+is thought that every one will have the same opinion.
+A roll or rope necessarily contains a large
+number of spaces, wrinkles, or irregularities, which
+must be obliterated by using force in order to produce
+a solid filling; thus more force is employed,
+and more time occupied in condensing a rope, than
+a flat tape; the individual blow in one case may not
+be heavier than in the other, but the rope has to be
+struck more blows. The idea that a rope could be
+fed into a cavity with a plugger faster and easier
+than a tape has long ago been disproved. Many
+of the old-fashioned non-cohesive gold foil operators
+used flat tapes, as did also Dr. Varney, one
+of the kings of modern cohesive gold operators.</p>
+
+<p>The tape is made by folding any portion of a
+sheet of foil upon itself until a certain width and
+thickness is obtained. This tape is very desirable
+in small or proximal cavities where a roll or rope
+would catch on the margin and partially conceal
+the view.</p>
+
+<p>In the form of a tape, perhaps more foil can be
+put in a cavity, and there may be more uniform
+density than when ropes are used. Tapes can also
+be made by folding part of a sheet of foil over a<span class='pagenum'><a name="Page_60" id="Page_60">[60]</a></span>
+thin, narrow strip of metal. Fold the tin into tapes
+of different lengths, widths, and thicknesses, according
+to the size of the cavity; then fold the end
+of the tape once or twice upon itself, place it at the
+base of any proximal cavity, and begin to condense
+with a foot plugger of suitable size, and if
+there is a pit, groove, or undercut which it does
+not reach, then use an additional plugger of some
+other form to carry the tin to place; fold the tape
+back and forth across the cavity, proceeding as for
+cohesive gold. In small proximal cavities a very
+narrow tape of No. 10, one thickness, can be used
+successfully. For cavities in the occlusal surface,
+use a tape as just described, generally beginning at
+the bottom or distal side, but the filling can be
+started at any convenient place, and with more ease
+than when using cohesive gold. In any case if the
+tin has a tendency to move when starting a filling,
+"Ambler's left-hand assistant" is used, by slipping
+the ring over the second finger of the left hand,
+letting the point rest on the tin. This instrument
+is especially valuable in starting cohesive gold (see
+<a href="#Fig_6">Fig. 6</a>). This is the easiest, quickest, and best
+manner of making a good filling, relying upon the
+welding or cohesive properties of the tin.</p>
+
+<p>Many operators have not tried to unite the tin
+and make a solid mass; they seem to think that it<span class='pagenum'><a name="Page_61" id="Page_61">[61]</a></span>
+cannot be accomplished, but with proper pluggers
+and manipulation it can be done successfully.</p>
+
+<div class="figc" style="width: 555px;"><a name="Fig_6" id="Fig_6"></a>Fig. 6.
+<img src="images/006.png" width="555" height="108" alt="" title="" />
+</div>
+
+<p>For large occlusal or proximal cavities, the
+tapes may be folded into mats, or rolled into cylinders,
+and used on the plan of wedging or interdigitation,
+and good fillings can be produced by this
+method, but the advantage of cohesion is not obtained,
+and more force is required for condensing.
+They are, therefore, not so desirable as tapes, especially
+for frail teeth. When using mats or cylinders,
+the general form of the cavity must be depended
+upon to hold the filling in place. To make
+the most pliable cylinders, cut a strip of any desired
+width from a sheet of foil and roll it on a triangular
+broach, cutting it off at proper times, to make the
+cylinders of different sizes.</p>
+
+<p>A cylinder roller, designed by the author, is
+much superior to a broach. (See <a href="#Fig_7">Fig. 7</a>.) When
+the cavity is full, go over the tin with a mallet or
+hand burnisher, being careful not to injure the cavity-margin.<span class='pagenum'><a name="Page_62" id="Page_62">[62]</a></span>
+Cut down occlusal fillings with burs or
+carborundum wheels, and proximal fillings with
+sharp instruments, emery strips or disks. After
+partially finishing, give the filling another condensing
+with the burnisher, then a final trimming
+and moderate burnishing; by this method a hard,
+smooth surface is obtained.</p>
+
+<p>Fillings on occlusal surfaces can be faced with
+No. 20 or 30 tin, and burnished or condensed, by
+using a burnisher in the engine, but do not rely
+upon the burnisher to make a good filling out of a
+poor one.</p>
+
+<div class="figc" style="width: 421px;"><a name="Fig_7" id="Fig_7"></a>Fig. 7.
+<img src="images/007.png" width="421" height="54" alt="" title="" />
+</div>
+
+<p>By trimming fillings before they get wet, any
+defects can be remedied by cutting them out; then
+with a thin tape (one or two layers of No. 10) and
+serrated plugger proceed with hand or mallet force
+to repair the same as with cohesive gold.</p>
+
+<p>Another method of preparing tin for fillings is
+to make a flat, round sand mold; then melt chemically
+pure tin in a clean ladle and pour it into the
+mold; put this form on a lathe, and with a sharp
+chisel turn off thick or thin shavings, which will<span class='pagenum'><a name="Page_63" id="Page_63">[63]</a></span>
+be found very tough and cohesive when freshly cut,
+but they do not retain their cohesive properties
+for any great length of time,&mdash;perhaps ten or
+twenty days, if kept in a tightly corked bottle.
+After more or less exposure to the air they become
+oxidized and do not work well, but when they are
+very thin they are soft, pliable, and cohesive as
+gold, and any size or form of filling can be made
+with them.</p>
+
+<p>Among the uses of tin in the teeth, the writer
+notes the following from Dr. Herbst, of Germany:
+"After amputating the coronal portion of the pulp,
+burnish a mat of tin foil into the pulp-cavity, thus
+creating an absolutely air-tight covering to the
+root-canal containing the remainder of the pulp;
+this is the best material for the purpose." There
+has been a great deal said about this method, pro
+and con, notably the latter. The writer has had no
+practical experience with it, and it need not be
+understood that he indorses it.</p>
+
+<p>If a pulp ever does die under tin, perhaps it will
+not decompose as rapidly as it otherwise would,
+owing to its being charged with tin-salts.</p>
+
+<p>The Herbst method of filling consists in introducing
+and condensing tin in cavities by means of
+smooth, highly tempered steel engine or hand burnishers.
+In the engine set of instruments there is<span class='pagenum'><a name="Page_64" id="Page_64">[64]</a></span>
+one oval end inverted cone-shaped, one pear-shaped,
+and one bud-shaped. The revolving burnisher
+is held firmly against the tin, a few seconds
+in a place, and moved around, especially along the
+margins, not running the engine too fast. Complicated
+cavities are converted into simple ones by
+using a matrix, and proximal cavities in bicuspids
+and molars are entered from the occlusal surface.
+The tin foil is cut into strips, and then made
+into ropes, which are cut into pieces of different
+lengths; the first piece must be large enough so
+that when it is condensed it will lie firmly in the
+cavity without being held; thus a piece at a time
+is added until the cavity is full. The hand set of
+burnishers has four which are pear-shaped and vary
+in size, and one which is rather small and roof-shaped.
+In filling and condensing they are rotated
+in the hand one-half or three-quarters of a turn.</p>
+
+<p>Dr. Herbst claims a better adaptation to the
+walls of the cavity than by any other method.
+Proximal cavities in bicuspids and molars can easily
+be filled; the tin can be perfectly adapted against
+thin walls of enamel without fracturing them; less
+annoyance to the patient and less work for the
+dentist; can be done in half the time required for
+other methods.</p>
+
+<p>Fees should be reasonably large, certainly more<span class='pagenum'><a name="Page_65" id="Page_65">[65]</a></span>
+than for amalgam, for we can save many teeth for
+a longer time than they could have been preserved
+with cohesive gold. Many are not able to pay for
+gold, but they want their teeth filled and <i>saved</i>, and
+it is expected that we will do it properly and with
+the right kind of material; thus it is our duty in
+such cases to use more tin and less amalgam.</p>
+
+<p>We should always take into consideration the
+amount of good accomplished for the patient,&mdash;the
+salvation of the tooth,&mdash;and if we are sure, from experience
+and observation, that the tin filling will
+last as long as a gold one in the same cavity, or
+longer, then the fee should be as much as for gold,
+with the cost of the gold deducted. The amount
+of the fee ought to be based upon the degree of
+intelligence, learning, and skill required; upon the
+amount of nervous energy expended; upon the
+draft made on the dentist's vitality; upon what
+benefit has been given the patient; upon the perfection
+of the result; and, everything else being equal,
+upon the time occupied; the value of this last factor
+being estimated in proportion to the shortness of it.</p>
+
+<hr /><p><span class='pagenum'><a name="Page_66" id="Page_66">[66]</a></span></p>
+<h2>CHAPTER VIII.</h2>
+
+<p><span class="smcap">Dr. Robinson's</span> Fibrous and Textile Metallic
+Filling is a shredded metallic alloy, mostly tin, and
+has the appearance of woven or felt foil. It is prepared
+in a machine invented by the doctor especially
+for the purpose, and he gives directions for
+using as follows: "Cut the material into strips
+running with the selvage, and fill as you would with
+soft foil; use it in all surrounding walls, and finish
+with a mallet burnisher. Where the surface comes
+to hard wear, weld on gold with long, sharp serrated
+pluggers, and finish the same as with gold
+fillings. The advantage over gold for cervical,
+buccal, and lingual walls is the perfect ease with
+which it is adapted, and it can be burnished so as
+to be absolutely impervious to moisture. Sharp,
+coarse-serrated pluggers are particularly desirable
+when using hand pressure." It comes in one-half-ounce
+boxes, filled with sheets less than two inches
+square; the thin ones are used for filling, and the
+thick ones make good linings for vulcanite.</p>
+
+<p>This material is easy to manipulate, but great
+care is required in condensing at cavity-margins,
+so as to make a tight filling, and also not injure the
+margins. It makes as hard a surface as tin foil, and<span class='pagenum'><a name="Page_67" id="Page_67">[67]</a></span>
+can be cut, polished, and burnished so that it is
+smooth and looks well; it can be used in temporary
+or chalky teeth, as a small amount of force condenses
+it. By using a matrix proximal cavities
+can be filled from one-fourth to one-half full, and
+the rest filled with gold, relying on the form of the
+cavity to hold the gold, regardless of its connection
+with the fibrous material. If the surface is not
+overmalleted so as to make it brittle or powdery, a
+strip of No. 4 cohesive gold, of four or five thicknesses,
+may be driven into it with a hand mallet and
+plugger of medium serrations; this union is largely
+mechanical, but of sufficient tenacity to make
+manipulation easy, as the material makes a solid
+foundation to build upon. After exposure to the
+oral fluids, electrolysis takes place at the junction
+of the metals.</p>
+
+<p>In 1884 Dr. Brophy said, "I have used Robinson's
+material for two years, and find it possesses
+good qualities, and can be used in deciduous teeth,
+first permanent molars, and cervical margins with
+better results than can be obtained with any other
+material by the majority of operators."</p>
+
+<p>Malleted with deeply serrated pluggers, it will
+make a filling which will not leak. It has saved
+many teeth from caries at the cervical margin
+where it might have recurred sooner had cohesive<span class='pagenum'><a name="Page_68" id="Page_68">[68]</a></span>
+gold been used. In the mouth it changes color
+about the same as tin foil, and a few fillings did not
+maintain their integrity, but became crumbly and
+granular.</p>
+
+<p>For conducting properties it ranks about with
+tin, and fillings can be made more rapidly than with
+cohesive gold. We have used ounces of it, but
+time has proved that everything that can be done
+with it in filling teeth can also be accomplished as
+well and in some cases better with tin foil.</p>
+
+<p>In 1878 Dr. N. B. Slayton patented his Felt Foil,
+which was said to be tin cut into hair-like fibers by
+a machine, then pressed into small sheets and sold
+in one-half-ounce books, but it sold only to a very
+limited extent. Soon after this Dr. Jere Robinson,
+Sr., invented a machine and began the manufacture
+of a similar article, but he found he was
+infringing on the Slayton patent, so he purchased
+the Slayton machine and made satisfactory terms
+to continue his own manufacture of fibrous material.
+After this little was heard of Slayton's Felt
+Foil, but Robinson's was considerably used. The
+two materials look and are manipulated almost
+exactly alike. Dr. Robinson has both of above-mentioned
+machines now in his possession.</p>
+
+<p>Archibald McBride, of Pittsburg, Pa., in 1838,
+made a roll of a portion of a sheet of tin, and then<span class='pagenum'><a name="Page_69" id="Page_69">[69]</a></span>
+used just enough gold to cover it, aiming to keep
+the gold on the surface, so as to have the filling
+look like one of all gold, and not with the idea of
+deriving any special benefit from the effects of wear
+or preservation as obtained by thus combining the
+two metals. The fee for a gold filling was one
+dollar; tin, fifty cents. Some operators have advocated
+using tin and gold (symbol Tg), rolled or
+folded together in alternate layers, thus exposing
+both metals to the fluids of the mouth; claiming
+that fillings can be made quicker, are not so subject
+to thermal changes, and can be inserted nearer the
+pulp than when gold is used. This may be true
+in comparison with gold, but these three claims are
+entirely met by using tin alone. Others say that
+this union of gold and tin will preserve the teeth as
+well as a correct gold filling, making no conditions
+or restrictions as to tooth-structure or location of
+cavity. They say that it preserves the cervical
+margin better than gold; that it expands <i>slightly</i>.</p>
+
+<p>A description of some different methods of combining
+and manipulating tin and gold is subjoined:</p>
+
+<p>(<i>a</i>) Two sheets of No. 4 cohesive gold and one
+of the same number of tin are used; place the tin
+between the gold, cut off strips, and use with hand
+or mallet force the same as cohesive gold; if non-cohesive
+gold is used, the strips can be folded into<span class='pagenum'><a name="Page_70" id="Page_70">[70]</a></span>
+mats or rolled into cylinders, and are used on the
+wedging plan, the same as non-cohesive gold, or
+the strips can be folded back and forth in the cavity
+until it is full.</p>
+
+<p>(<i>b</i>) Lay a sheet of non-cohesive gold, No. 3, on
+a sheet of tin of the same number, cut off strips, roll
+into ropes and use as non-cohesive gold. It is
+easily packed and harder than tin, and has a preservative
+action on the teeth. Line the cavity with
+chloro-balsam as an insulator against possible currents
+and moisture; especially should this be done
+in large cavities or chalky teeth.</p>
+
+<p>(<i>c</i>) A sheet of non-cohesive gold, No. 4, is laid
+on a sheet of tin of the same number, cut into strips
+and rolled into cylinders, or folded into blocks,
+always in equal portions; then they will unite to the
+extent of two leaves. These fillings sometimes
+become a solid mass about the color of amalgam,
+and last very well, as the metals have become united
+by electrolysis. An excess of tin will be marked by
+lines or pits in the filling, showing where the tin
+has been disintegrated or dissolved by the chemical
+action which occurs on the surface exposed to
+moisture.</p>
+
+<p>No doubt, good fillings have been made by the
+above methods, yet some were granular, gritty, and
+were easily removed, while others were quite<span class='pagenum'><a name="Page_71" id="Page_71">[71]</a></span>
+smooth and hard; probably in the first instance the
+proportion of tin and gold was not proper,&mdash;that is,
+not equal; or it was not well condensed. Tin being
+the positive element, it is more easily acted on and
+disintegrated by electrolysis (chemical action of the
+fluids).</p>
+
+<p>When this combination does become hard, it
+wears longer than tin on an occlusal surface, but
+we believe that in some cases where it was used the
+teeth could have been saved just as well with either
+tin or gold, or by filling part of the cavity with tin
+and the rest with gold.</p>
+
+<p>If tin foil is laid on 22-carat gold and vulcanized,
+it becomes thoroughly attached and will take a
+tin polish; the attraction or interchange of atoms
+takes place to this extent.</p>
+
+<p>This combination of tin and gold can be used at
+the cervical margin, or a cavity can be lined with it,
+and the remainder filled with cohesive or non-cohesive
+gold.</p>
+
+<p>"Tin and gold (Tg) folded or rolled together in
+equal portions possesses a greater number of desirable
+properties than any other material, for it is
+easily adapted, has antiseptic action and a lower
+conductivity than gold. A new filling is harder
+than tin, softer than gold, but after a time it becomes
+as hard as amalgam. It oxidizes and thus<span class='pagenum'><a name="Page_72" id="Page_72">[72]</a></span>
+helps make tight margins, and is very useful at cervical
+margins; generally discolors, but not always,
+and does not discolor the tooth unless a carious
+portion has been left, and then only discolors that
+portion. In oral fluids it is indestructible if well
+condensed, otherwise it is crumbly. There is no
+change of form, except a <i>slight</i> expansion, which
+does no harm. A weak electric current is set up
+between the gold and tin, and tin oxid is formed.
+The hardening and discoloration both depend upon
+the separation of the tin by the electrical action and
+its deposition on the surface of the gold. I generally
+prepare cavities the same as for non-cohesive
+gold, but a Tg filling may be held in a more shallow
+cavity and with less undercuts than for gold.
+Hand pressure is adopted, but a mallet may be
+used advantageously. Lay a sheet of No. 4 non-cohesive
+gold on a sheet of No. 4 tin, then cut into
+strips and twist into ropes; keep the tin on the outside,
+for it does not tear as easily as gold. Carry
+the material against the walls and not against the
+base, otherwise the filling will be flat or concave;
+but should this occur, then force a wedge-shaped
+plugger into the center of the filling, and drive the
+material toward the walls, and then fill the hole or
+remove all the filling and begin anew.</p>
+
+<p>"In very deep cavities use a mat of Tg, dampened<span class='pagenum'><a name="Page_73" id="Page_73">[73]</a></span>
+in carbolic acid and dipped in powdered
+thymol, as a base; this has an antiseptic action, and
+also prevents pressure on or penetration into the
+pulp.</p>
+
+<p>"Drs. Abbot, Berlin; Jenkins, Dresden; Sachs,
+Breslau, have observed tin-gold fillings from fifteen
+to twenty-five years, and say that for certain cases
+it is better than any other material. I use square-pointed
+pluggers (four-cornered), as part of the
+packing is done with the side of the plugger. Tg
+is useful in partly erupted molars, buccal cavities
+under the gums, occlusal cavities in temporary
+teeth, cavities where all decay cannot be removed.
+Use Tg with a gold capping in small, deep occlusal
+cavities, cavities with overhanging walls, occlusal
+cavities with numerous fissures, large, deep occlusal
+cavities near the pulp, in proximal cavities.</p>
+
+<p>"Line labial walls of incisors with non-cohesive
+gold, and fill the remainder with Tg. For repairing
+gold fillings I use Tg." (Dr. Miller, Berlin,
+<i>Dental Cosmos</i>, 1890.)</p>
+
+<p>Dr. Jenkins, of Dresden, says, "I use Tg in soft,
+imperfect teeth, of which there are plenty in Germany,
+because it has pliability, adaptability, slight
+susceptibility to thermal changes, makes a water-tight
+joint, very useful at cervical margins, and
+can be used with a minimum amount of pressure.<span class='pagenum'><a name="Page_74" id="Page_74">[74]</a></span>
+When packed dry and with the gold next
+to the tooth, discoloration occurs only on the surface;
+packed wet, the whole discolors. I do not
+attribute its success to electrical action. Lay a
+sheet of No. 4 tin on a sheet of No. 4 non-cohesive
+gold, fold so as to keep the gold on the outside; use
+the strip with lateral pressure, doubling it upon
+itself."</p>
+
+<p>Dr. A. H. Thompson: "After several years'
+successful use of tin-gold, I commend it for approximal
+cavities, cervical margins, and frail walls. The
+oxid formed penetrates the enamel and dentin; if a
+filling wears down, cover the surface with gold."</p>
+
+<p>Dr. Pearson: "I do not like tin and gold in
+alternate layers. I prefer No. 10 tin foil."</p>
+
+<p>Dr. James Truman: "I believe that tin-gold has
+a positive value as a filling-material."</p>
+
+<p>"I prepare tin-gold by taking a sheet of No. 4
+non- or semi-cohesive gold, fold them together (or
+twist them) so as to have the gold on the outside,
+and then fill any cavity with it. Since adopting the
+above combination I have almost abandoned amalgam.
+This is recommended on account of its
+density, ease of insertion, capacity for fine finish,
+non-conducting and non-shrinking qualities, and
+compatibility with tooth-substance. Those who
+have not used it will be surprised at the rapidity<span class='pagenum'><a name="Page_75" id="Page_75">[75]</a></span>
+with which it can be manipulated. It may be employed
+in any cavity not exposed to view, also in
+crown, buccal, and approximal fillings which extend
+into the occlusal surface, as it offers an astonishing
+resistance to wear. It can be used anywhere
+that amalgam can, and with more certainty
+of non-leakage, and it has the additional advantage
+that it can be finished at the same sitting. Care is
+necessary in manipulating it, so as to avoid chopping.
+I use hand pressure when filling, and the
+mallet to condense the surface." (Dr. A. W. Harlan,
+<i>Independent Practitioner</i>, 1884.)</p>
+
+<p>"Pure tin foil is employed in connection with
+non-cohesive gold in filling proximal cavities in bicuspids
+and molars; a sheet of gold and a sheet of
+tin are folded together." (C. J. Essig: "Prosthetic
+Dentistry.")</p>
+
+<p>Dr. Benj. Lord says, "A combination in which I
+find great interest is in the use of soft or non-cohesive
+gold with tin foil. This is no novelty in practice,
+but I think that, for the most part, too great
+a proportion of tin has been used, and hence has
+arisen the objection that the tin dissolved in some
+mouths. I am satisfied that I myself until recently
+employed more tin than was well. I now
+use from one-tenth to one-twelfth as much tin as
+gold, and no disintegration or dissolving away of<span class='pagenum'><a name="Page_76" id="Page_76">[76]</a></span>
+the tin ever occurs. I fold the two metals together
+in the usual way of folding gold to form strips, the
+tin being placed inside the gold. The addition of
+the tin makes the gold tougher, so that it works
+more like tin foil. The packing can be done with
+more ease and certainty; the filling, with the same
+effort, will be harder, and the edges or margins are
+stronger and more perfect.</p>
+
+<p>"The two metals should be thoroughly incorporated
+by manipulation. Then, after a time, there
+will be more or less of an amalgamation. By using
+about a sixteenth of tin, the color of the gold is so
+neutralized that the filling is far less conspicuous
+than when it is all gold, and I very often use such a
+proportion of tin in cavities on the labial surfaces of
+the front teeth.</p>
+
+<p>"If too much tin is employed in such cases, there
+will be some discoloration of the surface of the fillings;
+but in the proportion that I have named no
+discoloration occurs, and the surface of the filling
+will be an improvement on gold in color."</p>
+
+<p>"Dr. Howe. I would like to ask Dr. Lord
+whether, in referring to the proportions of tin and
+gold, he means them to be considered by weight?</p>
+
+<p>"Dr. Lord. No, not by weight, but by the
+width of the strip of tin and the width of the strip
+of gold. I get the proportions in that way, then<span class='pagenum'><a name="Page_77" id="Page_77">[77]</a></span>
+lay the tin on the gold and fold the gold over and
+over, which keeps the tin inside the gold.</p>
+
+<p>"Dr. Howe. Will Dr. Lord tell us whether he
+refers to the same numbers of gold foil and tin foil;
+as, for instance, No. 4 gold and No. 4 tin?</p>
+
+<p>"Dr. Lord. I use the No. 5 gold, and tin, I
+think, of about the same number, but I always use
+No. 5 gold, both cohesive and non-cohesive."&mdash;<i>New
+York Odontological Society Proceedings</i>, 1893,
+page 103.</p>
+
+<p>"Tin and gold, in the proportions generally used,
+do not present a pleasing color; when finished, it
+looks but little better than tin, and after a short
+time it grows dark, and sometimes black. I use
+five parts of gold to one of tin, prepared as follows:
+Lay down one sheet of Abbey's non-cohesive gold
+foil, No. 6; upon this place a sheet of No. 4; upon
+this place a sheet of White's globe tin foil, No. 4;
+upon this another sheet of Abbey's non-cohesive
+gold, No. 4; upon this a sheet of No. 6. Cut into
+five strips and crimp; the crimped strips are cut into
+pieces a little longer than the depth of the cavity
+to be filled; some of the strips are rolled into cylinders,
+others are left open, because easier to use in
+starting a filling. The color of this combination is
+slightly less yellow than pure gold, and hardens just
+as rapidly as when the proportions are one to one,<span class='pagenum'><a name="Page_78" id="Page_78">[78]</a></span>
+but does not become quite as hard. This preparation
+is non-cohesive, and should be inserted by
+the wedge process. I use it in the grinding surface
+of molars and bicuspids, buccal cavities in molars
+and bicuspids, cervical fissure pits in superior incisors,
+proximal cavities in bicuspids and molars.
+If proximal cavities are opened from the occlusal
+surface, the last portion of the filling should be of
+cohesive gold to withstand mastication. In simple
+cavities I place as many pieces as can be easily
+introduced, using my pliers as the wedging instrument
+to make room for the last pieces, and then
+condense the whole. If the cavity is too deep for
+this, I use Fletcher's artificial dentin as a base,
+because it partly fills the cavity and the ends of the
+cylinders stick to it. After an approximal cavity is
+prepared, use a matrix held in place by wooden
+wedges; the cylinders are about one-eighth of an
+inch long, and condensed in two or three layers so
+as to secure perfect adaptation; hand pressure is
+principally used, but a few firm strokes with a hand
+mallet are useful. When ready to add the cohesive
+gold for the grinding-surface, a few pieces of
+White's crystal mat gold should first be used, because
+it adheres beautifully; thus a perfect union is
+secured, but I never risk adding the gold without
+leaving a little undercut for it in the tooth. By<span class='pagenum'><a name="Page_79" id="Page_79">[79]</a></span>
+this method we obtain a beautiful contour filling
+in a short time. Fillings should be burnished and
+then polished with a fine strip, or moistened pumice
+on a linen tape. Where cohesive gold is used for
+the entire filling, in many cases the enamel-walls,
+already thin near the cervical margin, are made
+thinner by the unavoidable friction of the polishing
+strips, but tin and gold is so soft that a good surface
+is obtained in a few moments, and this danger
+is reduced to a minimum. The surface is as smooth
+as a cohesive gold filling, while such a surface is
+impossible with non-cohesive gold. In cavities
+which extend so far beyond the margin of the gum
+that it is impossible to adjust the rubber-dam, I
+prepare the cavity as usual, then adjust a matrix,
+disinfect, dry, and fill one-third full with tin and
+gold, then remove the matrix, apply the rubber,
+place matrix again in position, and complete the
+filling by adding a little tin and gold, then pure
+gold." (Dr. W. A. Spring, <i>Dental Review</i>, February,
+1896.)</p>
+
+<p>Dr. T. D. Shumway says, "To have a scientific
+method of treatment, there certainly must be a
+recognition of what is known of the nature of
+tooth-structure. The method adopted more than
+a quarter of a century ago, and which is at present
+employed, does not accord with the teachings of<span class='pagenum'><a name="Page_80" id="Page_80">[80]</a></span>
+the physiologist and microscopist; it is in direct
+opposition to natural law. Each new discovery in
+the minute structure of the teeth makes this more
+plain; pounding the teeth with a mallet cannot be
+defended on scientific grounds. That it has not resulted
+more disastrously is due to the wonderful recuperative
+energy of nature to repair injury. No
+one would think of attempting to arrest and prevent
+disintegration in any other vital organ by
+abrasion. Why, then, in operation on the teeth,
+should we reverse the plain, simple teaching of nature?
+Placing cohesive gold against the dentinal
+walls by pounding it to heal a lesion is opposed to
+natural law. Cohesive gold will not be mastered
+by force; if compelled to yield by superior strength,
+it seeks a way to release itself; it is easily coaxed,
+but not easily driven. Cohesive gold will unite
+with tin at an insensible distance just as cohesive
+gold unites with itself; this union takes place without
+force or pressure. Exactly what takes place
+when gold and tin are brought in contact in the
+way described we do not know; we can only say
+that there appears to be a perfect union. When cohesive
+gold was introduced to the profession, while
+it was softer than non-cohesive foil, it was found to
+resist under manipulation. This resistance is in accordance
+with the well-known law that all crystalline<span class='pagenum'><a name="Page_81" id="Page_81">[81]</a></span>
+bodies, when unobstructed, assume a definite
+form. With gold the tendency is to a spherical
+form. The process of crystallization is always from
+within outward. The mallet was introduced to
+overcome the resistance caused by the development
+of the cohesive property. Pounding gold with a
+mallet only increases its crystallization. A crystalline
+body coming in contact with a fibrous one
+can neither be antiseptic nor preservative; a filling-material
+which possesses these properties must be
+one that corresponds or is in harmony with tooth-substance.</p>
+
+<p>"In the interglobular spaces there is a substance
+which is called amorphous or structureless, and a
+filling to be in harmony with this substance should
+be amorphous or structureless in its composition.
+The only materials we have which meet these conditions
+are gutta-percha and tin. It is its structureless
+character that gives to tin its value. Coming
+in contact with the living dentin, it is easily
+adapted, and does not excite inflammation; it does
+not interfere with the process going on within the
+teeth to heal the lesion caused by caries. A wound
+from a bullet made of tin, unless it struck a vital
+part, nature would heal, even if the cause of the
+wound was not removed, by encysting the ball.
+This process of nature of repairing injury by encysting<span class='pagenum'><a name="Page_82" id="Page_82">[82]</a></span>
+the cause is of interest to the dentist in the
+study of suitable filling-materials. Tin is very useful
+at the cervical margin of cavities; it acts as an
+antiseptic or preservative, and reduces the liability
+to subsequent decay. It is our endeavor to obtain
+a filling that will preserve the teeth and reduce the
+liability to, if not wholly prevent, secondary decay.
+The law of correspondence is of more consequence
+than the mechanical construction of the filling.
+Tin can be used without that rigid adherence to
+mechanical rule that is necessary to retain a filling
+of cohesive gold; thus less of the tooth needs to be
+sacrificed.</p>
+
+<p>"Gold will unite with tin under certain conditions
+so as to form apparently a solid mass. By
+a combination of these metals, not by interlacing
+or incorporating one in the other, but by affinity,
+secured by simple contact, we have all the preservative
+qualities of tin combined with the indestructible
+properties of gold. For the base of the
+filling we have a material in harmony with tooth-substance,
+introduced in a way that is in accord
+with the law that governs all living bodies, and for
+the outside a crystalline substance that corresponds
+to the covering of the teeth. This covering
+of gold is a perfect shield to the base, and the
+field for the display of artistic skill in restoring<span class='pagenum'><a name="Page_83" id="Page_83">[83]</a></span>
+contours is as broad as though gold was used entirely.
+Will a filling of this kind withstand mastication?
+There is in the economy of nature a provision
+made to overcome the resistance of occlusion.
+The teeth are cushioned in the jaw and yield
+under pressure. The elasticity of the substance
+of which the teeth are made is well understood.
+Ivory is the most elastic substance known. The
+teeth coming together is like the percussion of two
+billiard balls. Now a filling to save the teeth
+should correspond as nearly as possible with the
+tooth-substance; it should not be arbitrary, but
+elastic and yielding. Tin is interdigitous; it expands
+laterally, and is almost as easily introduced
+as amalgam, and when put in place does not have
+to be bound to be retained. Tin, with an outside
+covering of gold to protect it, makes a filling to
+which amalgam bears no comparison. In the
+light of scientific investigation there can be but
+one method&mdash;a method based upon the recognized
+principle that the <i>filling-material</i> and the <i>manner</i>
+of <i>introducing</i> it shall correspond to and be in harmony
+with the living, vital organism with which
+it comes in contact.</p>
+
+<p>"After excavating, the cavity is treated with
+absolute alcohol, as cleanliness and thorough dryness
+are absolutely essential.<span class='pagenum'><a name="Page_84" id="Page_84">[84]</a></span></p>
+
+<p>"The <i>tin</i> is put in with steel pluggers, after the
+method of wedging; it must be thoroughly condensed,
+so as to leave a smooth surface, and
+enough used to come up to where the enamel and
+dentin join.</p>
+
+<p>"The effect is not produced by incorporating or
+interlacing the gold with the tin; we rely upon the
+affinity of the two metals to retain the gold; no
+undercuts, angles, or pits are made in the tin,
+dentin, or enamel. The gold, extra cohesive from
+No. 4 to 40, is made to adhere to the tin by simple
+contact, without pressure or force; the union is not
+mechanical.</p>
+
+<p>"The instruments used for filling the remainder
+of the cavity with gold are Shumway's ivory points,
+which adapt the gold nicely to the margin.</p>
+
+<p>"The set consists of five and were patented in
+1881, and have been used by me since that time
+for manipulating cohesive gold. One 'point' is
+for proximal cavities in the anterior teeth; three
+'points' of different sizes are for occlusal cavities;
+one 'point' for proximal cavities in bicuspids and
+molars and labial and buccal cavities; the sides,
+edges, and ends of the 'points' are used, as the
+purpose is simply to obtain contact.</p>
+
+<p>"The 'point' shown full size in <a href="#Fig_8">Fig. 8</a> is of more
+general application than any of the others, and is<span class='pagenum'><a name="Page_85" id="Page_85">[85]</a></span>
+used for proximal cavities in bicuspids,
+also labial and buccal cavities. The
+handle is made of ebony, and has a silver
+ferrule, from which the ivory extends to
+the end and completes the instrument.</p>
+
+<p>"The metal pin in the end of the
+handle is for picking up and carrying the
+gold."</p>
+
+<div class="figl" style="width: 30px;"><a name="Fig_8" id="Fig_8"></a><span class="sp1">Fig.&nbsp;8.</span>
+<img src="images/008-1.png" width="30" height="635" alt="" title="" />
+</div>
+
+<div class="figl1">&nbsp;
+<img src="images/008-2.png" width="29" height="227" alt="" title="" />
+</div>
+
+<p>Tin has been used successfully for
+completely lining cavities, filling the remainder
+with gold; it is also useful for repairing
+gold fillings.</p>
+
+<p>Two or three thicknesses of tin foil may be
+pressed into a cavity with a rubber point or hard
+piece of spunk, allowing it to come well out to the
+margin; filling the rest with amalgam.</p>
+
+<p>"As a lining it presents to dentin an amalgam
+of tin and mercury which does not discolor the dentin
+like ordinary amalgam, and helps do away with
+local currents on the filling, which is one cause of
+amalgam shrinkage in the mouth." (Dr. S. B.
+Palmer.)</p>
+
+<p>When caries extends to the bifurcation of roots,
+make a mat of two or three layers of tin, place it in
+the bifurcation and use it as a base in filling the
+rest of the cavity with amalgam.</p>
+
+<p>Tin is second in importance in alloys for amalgam,
+as it increases plasticity, prevents discoloration,<span class='pagenum'><a name="Page_86" id="Page_86">[86]</a></span>
+reduces conductivity and edge strength,
+retards setting, favors spheroiding, therefore
+should not be the controlling metal.</p>
+
+<p>It will be noticed that when cavities are lined
+with tin foil, it only constitutes a small part of
+the filling, and that it has not been melted with
+the other metals in the alloy before being amalgamated.</p>
+
+<p>A thick mat of tin has been recommended as a
+partial non-conductor under amalgam fillings.</p>
+
+<p>Plastic tin can be made by pouring mercury
+into melted tin, or by mixing the fillings with mercury
+at ordinary temperatures; it has a whitish
+color, and if there is not too much mercury it
+occurs in the form of a brittle granular mass of
+cubical crystals. Generally amalgams of tin and
+mercury do not harden sufficiently, but forty-eight
+parts of mercury and one hundred of tin make a
+fairly good filling, said to have a therapeutical
+value; it should not be washed or squeezed before
+using, and "is not a chemical combination."</p>
+
+<p>"Tin unites with mercury in atomic proportions,
+forming a weak crystalline compound." (Dr. E.
+C. Kirk.)</p>
+
+<p>Mercury and tin readily unite as an amalgam
+under ordinary circumstances, and form a definite
+chemical compound having the formula Sn<sub>2</sub>Hg.
+(Hodgen.)<span class='pagenum'><a name="Page_87" id="Page_87">[87]</a></span></p>
+
+<p>Another preparation of tin is known as stannous
+gold; it is manufactured in heavy sheets and used
+the same as cohesive gold foil, and can be easily
+manipulated, for it is rather plastic.</p>
+
+<p>Crystal tin for taking the place of tin foil:</p>
+
+<p>"Take chemically pure hydrochloric acid and
+dissolve tin foil in it until a saturated solution is
+obtained; this may be done speedily by heating
+the acid to a boiling point, or the same thing can
+be accomplished in a few hours with the acid cold;
+it is then chlorid of tin. It is then poured into a
+clean vessel and an equal quantity of distilled water
+added; then a clean strip of zinc is plunged into the
+solution, and tin crystals are deposited on the zinc;
+when there is sufficient thickness on the zinc, remove
+both, and slip the crystals off from the zinc
+into pure water, clean the zinc thoroughly, and reinsert
+for another coating. The character of the
+crystallization will be modified by the extent of the
+dilution of the solution in the first place. Wash
+the tin in pure water until all traces of the acid are
+removed, or a few drops of ammonia can be added
+to neutralize the acid. It was suggested that it
+would be desirable to have some acid remain in the
+tin for filling teeth in which there is no sensitive
+dentin. We have put in a few fillings, and it works
+beautifully, and makes firmer fillings than foil. It<span class='pagenum'><a name="Page_88" id="Page_88">[88]</a></span>
+must be kept in water (probably alcohol is better).
+It is pure tin, unites perfectly, and works easier
+than foil." (Dr. Taft, <i>Dental Register of the West</i>,
+1859.)</p>
+
+<p>For some years it was considered the best practice
+to enlarge all root-canals and fill them with
+gold; in many of these cases the crown cavities
+were filled with tin.</p>
+
+<p>Tin has been used for filling root-canals, but
+should there happen to be any leakage through
+the foramen or tooth-structure, the tin will discolor,
+and there may be infiltration into the crown,
+thus causing discoloration, which might be objectionable
+if the crown was filled with gold. Chloro-percha,
+gutta-percha, and oxychlorid of zinc are
+much better for this purpose.</p>
+
+<p>The apical quarter of a canal has been filled with
+tin, and the remainder with cement. Tin can be
+used for filling root-canals. Roll on a broach
+small triangular pieces of the foil into very small
+cone-shaped cylinders, carry to place, then withdraw
+the broach, and force in the cylinder with the
+same or a larger broach; sometimes it is necessary
+to use another broach, to push the cylinder off from
+the one on which it is rolled. Another method is
+to carry and pack into the canal by means of a
+broach, very narrow strips of No. 10 or 20 foil; or<span class='pagenum'><a name="Page_89" id="Page_89">[89]</a></span>
+the apical third of the canal could be filled with
+gold and the rest with tin.</p>
+
+<p>"About four years ago I concluded to try tin
+for filling root-canals; then I began to look for
+patients whose general health was good, who had
+strong, hardy-looking teeth, and kept their
+mouths in good condition. I found one who
+answered all my requirements, with a molar to be
+filled, and they would not have it filled with gold,
+or could not, on account of the expense. I filled
+the canals with tin and the crown with amalgam.
+After filling thirty-eight molars in this way I
+stopped for developments. In six or seven weeks
+a lady returned with an inferior molar abscessed,
+but at the time it was filled the circumstances
+were such that it could not be properly treated.
+In nine months a gentleman for whom I had filled
+four molars returned with an inferior one abscessed.
+This is the sum-total of abscessed teeth
+where tin was used in the root-canals, at the end of
+four years. The others are in good condition, as
+I have seen them every six months. The roots
+were treated from four to six weeks with carbolic
+acid before filling." (Dr. A. W. Harlan, <i>Missouri
+Dental Journal</i>, 1872.)</p>
+
+<p>"Tin foil is just as good as gold for filling root-canals,
+as it is entirely innocuous and sufficiently<span class='pagenum'><a name="Page_90" id="Page_90">[90]</a></span>
+indestructible, while its softness and pliability commend
+it. Where gold is to be used for the crown,
+it is better to fill the bulbous portion of the pulp-cavity
+with gold also, so as to weld these portions
+of gold together. The success of Dr. Harlan's
+treatment was about equal to what might be expected
+from the same number of teeth where the
+canals had been filled with gold." (Editor, <i>Missouri
+Journal</i>.)</p>
+
+<p>Shavings turned from a disk of pure tin have
+been used in combination with Watts's sponge gold
+for filling teeth, either by making a portion of the
+filling from each metal or using them indiscriminately.</p>
+
+<p>A mat of tin foil dipped in chloro-percha can be
+used to cap an exposed pulp, or a concave tin
+disk can be used for the same purpose. A mat of
+tin has been used over a slight exposure of the
+pulp, because of its slight conduction of heat and
+cold, thus avoiding much thermal irritation and
+stimulating recuperation.</p>
+
+<p>Some use Robinson's fibrous material as a surface
+for tin fillings, thinking that it is harder and
+will wear longer because of the erroneous notion
+that it has platinum in it.</p>
+
+<hr /><p><span class='pagenum'><a name="Page_91" id="Page_91">[91]</a></span></p>
+<h2>CHAPTER IX.</h2>
+
+<p><span class="smcap">Tin</span> has been recommended for temporary fillings
+in sensitive cavities, because it is soft and
+easily packed in contact with the walls, has therapeutic
+value, and after a time, when the temporary
+filling is removed, the cavity is not as sensitive as
+formerly.</p>
+
+<p>It has been observed that starting gold in a
+sensitive cavity causes pain, but starting tin in the
+same place seldom does.</p>
+
+<p>As long as tin preserves its integrity it preserves
+the tooth, therefore tin fillings should not
+be repaired with amalgam, as their integrity may
+be destroyed. Cavities can be partly filled with
+tin and completed with sponge, fibrous, or crystalloid
+gold, after the manner described for beginning
+with tin and finishing with gold foil.</p>
+
+<p>"I advocated tin at the cervical wall, cervico-lingual
+and cervico-buccal angles to the thickness
+of 24 plate. Then complete the filling with gold.
+Some of my most successful efforts in saving soft
+teeth have been made in this way. This method
+has great value over gold for the whole filling, but
+there are two objections to it: First, it imparts to
+the cervical border the color and appearance of<span class='pagenum'><a name="Page_92" id="Page_92">[92]</a></span>
+decay, so that in three cases where an instrument
+passed readily into the tin I have removed the fillings,
+without any necessity for it, not even finding
+any softening of the margins. Second, its use requires
+the same conditions of dryness, shape of cavity,
+delicate manipulation, inconvenience to patient,
+and strain upon the operator as when gold is used
+alone." (Dr. D. D. Smith, <i>Dental Cosmos</i>, 1883.)
+He admits that this method saves <i>soft</i> teeth and
+also cervical margins. Do not those two very important
+factors more than counterbalance the color,
+and oversight of the dentist?</p>
+
+<p>Dryness is an essential in making the best filling
+with any material, and the time and strain consumed
+by the majority of operators in filling with
+tin is not more than one-half what it is in using
+gold.</p>
+
+<p>"I use tin at the cervical margin of all proximal
+cavities in bicuspids and molars. I prepare a
+matrix of orange-wood to suit each case, letting
+it cover about one-third of the cavity, then fill with
+tin condensed by hand force and automatic mallet;
+now split the matrix and carefully remove it piece
+by piece, so as not to disturb the tin; then trim and
+finish this part of the filling. Make another
+wooden matrix, which covers the tin and remainder
+of the cavity, and fit it snugly to place. Use<span class='pagenum'><a name="Page_93" id="Page_93">[93]</a></span>
+a coarsely serrated plugger and begin packing
+non-cohesive gold into the tin, letting it fill about
+one-third more of the cavity; then complete the
+last third (surface) with cohesive gold. I have
+tested this method for twenty years, and it has
+given me splendid results. I always tell patients
+that there will appear sooner or later a slight discoloration
+near the gum, which must not be mistaken
+for caries." (Dr. A. P. Burkhart.)</p>
+
+<p>Another use for tin in the operating-room is
+found in Screven's "Gutta-percha-coated Tin
+Foil," a cohesive, antiseptic non-conductor, of
+which the inventor says: "Cement fillings that
+have been kept dry for ten hours after mixing will
+be much harder than those soon exposed to moisture,
+and they will retain that hardness though
+exposed to moisture afterward. This preparation
+will keep a filling perfectly dry in the mouth, and
+when removed the filling will be found hard as
+stone. There is nothing better for lining cavities,
+holding nerve-caps in position, holding a preparation
+in place when devitalizing a pulp where the
+tooth is so much broken away as to make it difficult
+to prevent a filling showing through the enamel,
+and for many other purposes."</p>
+
+<p>High-heat gutta-percha has been used as a base
+in deep occlusal, buccal, and approximal cavities,<span class='pagenum'><a name="Page_94" id="Page_94">[94]</a></span>
+completing the fillings with tin. Occlusal cavities
+may be filled with tin; then after the filling is condensed
+and finished, drill out the center and fill
+with cohesive gold, not cutting away the tin so
+as to expose the margin; such fillings wear well,
+as much of the attritial force comes on the gold
+portion of the filling.</p>
+
+<p>With the exception of the part in brackets, the
+following article is from the <i>British Journal</i>, May,
+1887:</p>
+
+<p>"If a person eats an oyster stew at 130&deg; F., a
+gold filling would carry the difference between the
+temperature of the stew and that of the mouth,
+130&nbsp;-&nbsp;98&nbsp;=&nbsp;32&deg;, almost undiminished to the
+bottom of the cavity; allowing 2&deg; of diminution,
+then the cavity around the gold filling has assumed
+128&deg;; now the person feels warm and drinks
+ice-water at 32&deg;. Taking into consideration the
+specific heat of the gold filling, it will assume about
+40&deg;, which it carries with a diminution of the cold
+of about 4&deg;,&mdash;that is, as if it was 44&deg;,&mdash;into the
+interior of the cavity; then the cavity will assume
+44&deg;, the difference within one-tenth of a minute
+being 128&nbsp;-&nbsp;44&nbsp;=&nbsp;84&deg;, a change which would produce
+a violent inflammation in any organ which
+was not accustomed to it. This derangement in<span class='pagenum'><a name="Page_95" id="Page_95">[95]</a></span>
+the tooth means interruption of circulation, and
+young teeth will be most affected.</p>
+
+<p>"Thermal effect depends on heat-conducting
+power [gold is nearly four times as good a conductor
+of heat as tin] and also on specific heat,
+so the more the latter approaches that of the
+tooth the less it is liable to produce sudden
+changes [thus favoring tin]. Specific heat manifests
+itself by the speed of changes, while the heat-conducting
+power influences the intensity [then
+the intensity of heat in a gold filling would be three
+or four times as much as in a tin filling]. In speed
+gold produces this change in one-tenth of a minute"
+[tin in one-fifth,&mdash;that is, gold absorbs heat
+and expands about twice as fast as tin].</p>
+
+<p>In 1838 Dr. J. D. White introduced sharp-wedge-shaped
+instruments for filling teeth, and he
+claims to have been the first to use them; they pack
+laterally as well as downward, and present as small
+a surface to the filling as possible, so that the
+greatest effect may be produced upon a given surface
+with a given power. Rolls of either tin or
+gold are made by cutting any desirable portion
+from a sheet of No. 4 foil; cut this portion once
+transversely, place on a napkin or piece of chamois,
+then with a spatula fold a very narrow portion of
+the edge once upon itself; then with the spatula<span class='pagenum'><a name="Page_96" id="Page_96">[96]</a></span>
+resting on the thickened edge draw the spatula
+away from it with gentle pressure, and the foil will
+follow in a roll.</p>
+
+<div class="figc" style="width: 211px;"><a name="Fig_9" id="Fig_9"></a>Fig. 9.
+<img src="images/009.png" width="211" height="240" alt="" title="" />
+</div>
+
+<p>The old method of using rolls, ropes, and tapes
+or strips is the same, but we will describe one
+method of using tapes. (See <a href="#Fig_9">Fig. 9</a>.) A <i>strip</i> is a
+single thickness of foil in ribbon form; a strip
+folded lengthwise once, twice, or more forms a <i>tape</i>
+of two, four, or more thicknesses of foil. The tin
+foil should be cut into strips and folded into tapes
+proportioned in width and thickness to the size of
+the cavity. One end of the tape is carried to the
+bottom of the cavity and then forced against the
+side opposite the point where we intend to finish;
+now remove the wedge-shaped plugger and catch<span class='pagenum'><a name="Page_97" id="Page_97">[97]</a></span>
+the tape outside of the cavity, and fold another
+portion against that already introduced, letting all
+the folds extend from the bottom to a little beyond
+the margin. Proceed in this manner, with care
+and sufficient force, until the cavity is full, using for
+the last folds a small instrument. Condense the
+surface with a large plugger, then go over it carefully
+with a small instrument, and if any part yields,
+force in a wedge-shaped plugger and fill the opening
+in above-described manner; condense, burnish,
+and trim alternately until the surface is level with
+the cavity-margin. By extending the folds from
+the orifice to the base of the cavity, the liability of
+the tin to crumble or come out is effectually prevented,
+and by putting it in with a wedge-shaped
+plugger it is pressed out into all depressions of the
+walls.</p>
+
+<p>A later method of filling with tape or rope is to
+use wedge-shaped pluggers with sharp serrations,
+filling the <i>ends</i> of the cavity, and as the two parts
+approach each other that next to the wall should
+be in advance of the rest, thus an opening will be
+left in the center which can be filled with a smaller
+tape or rope.</p>
+
+<p>Another old method: Take a piece of foil and
+roll it into a hard ball; then gradually work it into<span class='pagenum'><a name="Page_98" id="Page_98">[98]</a></span>
+the cavity, being careful to have sufficient around
+the margin.</p>
+
+<p>Still another suggested method: Roll a piece
+of foil into a loose ball, place it in the cavity, and
+pass a wedge-shaped plugger into its center. This
+has the effect of spreading the tin toward the walls
+of the cavity, the opening to be filled with folds in
+a way already described. The wedge is used as
+often as it can be made to enter, filling each opening
+with folds; then condense the surface, trim, and
+burnish.</p>
+
+<div class="figc" style="width: 191px;"><a name="Fig_10" id="Fig_10"></a>Fig. 10.
+<img src="images/010.png" width="191" height="221" alt="" title="" />
+</div>
+
+<p>The English give the Americans the credit of
+first using cylinders. Anyhow, Dr. Clark, of New
+Orleans, in 1855, used them made from non-cohesive
+gold, and also from gold and tin in alternate
+layers. (See <a href="#Fig_10">Fig. 10</a>.)<span class='pagenum'><a name="Page_99" id="Page_99">[99]</a></span></p>
+
+<p>Cylinders were used which were a little longer
+than the depth of the cavity, introduced with
+wedge-shaped pluggers around the walls, each one
+being closely adapted to the margin; then another
+row was added, which was forced firmly against
+the preceding, continuing this process until the
+cavity was full. The wedge, having a smooth end
+and sides, is forced into the center so as to drive
+the tin toward the sides of the cavity, being careful
+not to split the tooth; the opening is then filled
+with a cylinder. Now force a smaller-sized wedge
+into the center of the last cylinder, and into the
+opening introduce another cylinder, proceeding in
+this manner until the filling is solid. Then condense
+the ends of the cylinders, trim, and burnish.
+For the same operation more recent pluggers are
+wedge-shaped, with sharp, deep serrations. In
+these cases the filling is retained by the general
+form of the cavity and wedging within a certain
+limit, and not by cohesion of the different parts.
+For a time tin cylinders were prepared and put on
+sale at the dental depots.</p>
+
+<p>As far as we are aware, the first tin foil made use
+of in operative technics was by Dr. F. S. Whitslar,
+who removed a disk of German silver from an ivory
+knife-handle in 1845, then used hand pressure to
+fill the cavity with tin. In the college course of<span class='pagenum'><a name="Page_100" id="Page_100">[100]</a></span>
+operative technics tin foil can be used, almost to
+the exclusion of gold foil, to demonstrate the
+manipulation of both cohesive and non-cohesive
+gold. Shavings scraped from a bar of tin are also
+useful in operative technics; they are more cohesive
+than foil.</p>
+
+<div class="trn"><b>Transcriber's Note:</b>
+Minor typographical errors have been corrected without note.
+Variant and obsolete spellings, particularly chemical terms, have been retained.</div>
+
+
+
+
+
+
+
+
+<pre>
+
+
+
+
+
+End of the Project Gutenberg EBook of Tin Foil and Its Combinations for
+Filling Teeth, by Henry L. Ambler
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+</body>
+</html>
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+The Project Gutenberg EBook of Tin Foil and Its Combinations for Filling
+Teeth, by Henry L. Ambler
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+Title: Tin Foil and Its Combinations for Filling Teeth
+
+Author: Henry L. Ambler
+
+Release Date: October 8, 2008 [EBook #26840]
+
+Language: English
+
+Character set encoding: ASCII
+
+*** START OF THIS PROJECT GUTENBERG EBOOK TIN FOIL ***
+
+
+
+
+Produced by Stephen Blundell and the Online Distributed
+Proofreading Team at http://www.pgdp.net (This file was
+produced from images generously made available by The
+Internet Archive/American Libraries.)
+
+
+
+
+
+
+
+
+
+                               TIN FOIL
+                               AND ITS
+                   COMBINATIONS FOR FILLING TEETH.
+
+
+                                 BY
+                HENRY L. AMBLER, M.S., D.D.S., M.D.,
+ Professor of Operative Dentistry and Dental Hygiene, in the Dental
+              Department of Western Reserve University.
+ Member of the American Dental Association; of the Ohio State Dental
+          Society; of the Northern Ohio Dental Association;
+                of the Cleveland City Dental Society.
+
+
+                            PHILADELPHIA:
+                  THE S. S. WHITE DENTAL MFG. CO.,
+                               LONDON:
+                    CLAUDIUS ASH & SONS, Limited.
+                                1897
+
+
+
+
+  Copyright, HENRY L. AMBLER, 1896.
+        All rights reserved.
+ Entered at Stationers Hall, London.
+
+
+Transcriber's Note:
+
+    Minor typographical errors have been corrected without note. Variant
+    and obsolete spellings, particularly chemical terms, have been
+    retained. The oe ligature is represented by [oe]. Subscript
+    characters are shown _{thus}, for example H_{2}O.
+
+
+
+
+PREFACE.
+
+
+Believing that sufficient and well-deserved prominence was not being
+given to the use of tin foil and its combinations, the author decided to
+present a brief historical resume of the subject, together with such
+practical information as he possesses, before the profession in order
+that it may have the satisfaction of saving more teeth, since that is
+the pre-eminent function of the modern dentist. One object is to meet
+the demand for information in regard to the properties and uses of tin
+foil; this information has been sought to be given in the simplest form
+consistent with scientific accuracy. The present use of tin is a case of
+the "survival of the fittest," because tin was used for filling teeth
+more than one hundred years ago. There is not a large amount of
+literature upon the subject, and no single text-book has treated the
+matter fully enough to answer the needs of both teacher and pupil. It is
+difficult for the student to collect and harmonize from the many
+different sources just the kind and amount of information required for
+his special use. Perhaps this work will be of assistance to scientific
+students and practical operators in the art of using tin foil, including
+all who wish in compact form an explanation of the facts and principles
+upon which the art is based. A good method to arouse in students an
+interest in the use of tin foil is to have them use it in operative
+technics, which is becoming an effective adjunct in every dental
+college. By this means a great factor will be brought to bear, and the
+result will be that hundreds of graduates every year will begin
+practice better qualified to save teeth than if they had not known
+whatever may be learned about this material. At the University of
+Pennsylvania, Department of Dentistry, session 1896-97, out of the total
+number of fillings made in the clinical department (fractions omitted)
+55 per cent. were gold, 15 per cent. tin, 10 per cent. amalgam. This
+shows that tin has some very strong friends in the persons of Professors
+Darby and Kirk.
+
+The historical sketch of the development of the subject is arranged in
+chronological order, and is given partly to show that some old ideas and
+methods were good, and some obviously incorrect when viewed in the light
+of more recent developments. Part of the history will be new to the
+oldest members of the profession, and the younger ones will certainly
+read it with interest. The work has been brought up to date by
+considering all the properties and methods available. More names, good
+opinions, and dates could have been given, but the writer believes that
+what is herein presented is enough to thoroughly substantiate his own
+opinions, experiments, and practical applications. Some of the
+illustrations have been made especially for this work; the others have
+been obtained through the courtesy of the owners.
+
+"Let not the foggy doctrine of the superiority of gold in all cases act
+on progress as the old medieval superstitions acted on astronomy,
+physiology, zoology. Truth sought after without misgiving, and the
+humblest as well as the highest evidence taken in every case, and acted
+on with skill and discrimination, will crown all with a high average of
+success."
+
+It is hoped that what has been said in this volume will enable those who
+study it to save more teeth, and stimulate them to make improvements on
+the material and methods, doing much better than has been described or
+suggested.
+
+CLEVELAND, OHIO, June, 1897.
+
+
+
+
+    "With soft and yielding lamina, and skill,
+    The practiced dental surgeon learns to fill
+    Each morbid cavity, by caries made,
+    With pliant tin; when thus the parts decayed
+    Are well supplied, corrosion, forced to yield
+    To conquering art the long-contested field,
+    Resigns its victim to the smiles of peace,
+    And all decay and irritation cease."
+                                      (_Solyman Brown._)
+
+The quantity of tin foil used measures the number of teeth saved with
+_metals_ in any country during any historical period.
+
+
+
+
+CONTENTS.
+
+
+                               CHAPTER I.                           PAGE
+ Antiquity of Tin--Alchemistic Name--Medical Use--Where Found--
+   Purity Obtained--Physical Characteristics                           1
+
+                              CHAPTER II.
+ History of the Use of Tin Foil, 1783-1844                             7
+
+
+                              CHAPTER III.
+ History Continued, 1845-1895                                         15
+
+                              CHAPTER IV.
+ Columbian Dental Congress--Opinions on Tin Foil--Reasons for
+   Using--Manufacture in United States--Number and Weight of
+   Foil--Cohesion--Good Qualities of Tin Foil--Temporary Teeth--
+   Thermal Changes--Calcification--Chalky Teeth                       27
+
+                               CHAPTER V.
+ Discoloration of Tin--Decomposition of Food--Sulfids--Oxids--
+   Galvanic, Therapeutic, and Chemical Action                         40
+
+                              CHAPTER VI.
+ White Caries--Gold and Tin as Conductors--Wearing Away of
+   Fillings--Poor Foil--Buccal Cavities--Number of Years
+   Fillings Last--Strips or Tapes for Filling--Number 10 Foil--
+   Form of Cavities--Shields--Matrices--Condensing--Finishing--
+   Cervical Margins--Filling Anterior Teeth--Lining with Gold         49
+
+                              CHAPTER VII.
+ Filling, part Tin, part Gold--Cervical Margin Liable to
+   Caries--Electrolysis--Hand Pressure--Hand Mallet--Tapes and
+   Ropes Compared--Manner of Preparing Foil--Starting the
+   Filling--Cylinders--Mats--Facing and Repairing--Tin
+   Shavings--Dr. Herbst's Method--Fees                                56
+
+                             CHAPTER VIII.
+ Dr. Robinson's Fibrous and Textile Metallic Filling--Tin and
+   Gold combined (Tg), Methods of Preparing and Using--Lining
+   Cavities with Tin--Tin and Amalgam--Plastic Tin--Stannous
+   Gold--Crystal Tin--Filling Root-Canals--Tin and Watts's
+   Sponge Gold--Capping Pulps                                         66
+
+                              CHAPTER IX.
+ Temporary Fillings--Sensitive Cavities--Integrity--Tin with
+   Sponge, Fibrous, and Crystallized Gold--Tin at Cervical
+   Margin--Filling Completed with Gold--Gutta-Percha and Tin--
+   Occlusal Cavities with Tin and Gold--Comparison of Gold with
+   Tin--Wedge-shaped Instruments--Old Method of Using Rolls,
+   Ropes, Tapes, or Strips--Later Method--Filling with Compact
+   and Loose Balls--Cylinder Fillings--Operative Technics             91
+
+
+
+
+CHAPTER I.
+
+
+Moses, who was born 1600 B.C., mentions tin, and history records its use
+500 B.C., but not for filling teeth; much later on, the Ph[oe]nicians
+took it from Cornwall, England, to Tyre and Sidon.
+
+The alchemistic name for tin is Jove, and in the alchemistic
+nomenclature medicinal preparations made from it are called Jovial
+preparations.
+
+Hindoo native doctors give tin salts for urinary affections. Monroe,
+Fothergill, and Richter claim to have expelled worms from the human
+system, by administering tin filings.
+
+Blackie, in "Lays of Highlands and Islands," referring to tin as money,
+says,--
+
+    "And is this all? And have I seen the whole
+    Cathedral, chapel, nunnery, and graves?
+    'Tis scantly worth the tin, upon my soul."
+
+"Tin-penny."--A customary duty formerly paid to the tithingmen in
+England for liberty to dig in the tin-mines.
+
+In 1846, Tin (Stannum, symbol Sn) was found in the United States only at
+Jackson, N. H. Since then it has been found, to a limited extent, in
+West Virginia and adjoining parts of Ohio, North Carolina, Utah, and
+North Dakota. The richest tin mines of the world, however, are in
+Cornwall, England, which have been worked from the time of the
+Ph[oe]nician discovery.
+
+The tin which is found in Malacca and Banca, India, is of great purity,
+and is called "Straits Tin" or "Stream Tin." It occurs in alluvial
+deposits in the form of small rounded grains, which are washed, stamped,
+mixed with slag and scoriae, and smelted with charcoal, then run into
+basins, where the upper portion, after being removed, is known as the
+best refined tin. Stream tin is not pure metallic tin, but is the result
+of the disintegration of granitic and other rocks which contain veins of
+tinstone. Banca tin is 99.961 parts tin, 0.019 iron, 0.014 lead in 100
+parts; it is sold in blocks of 40 and 120 pounds, and a bar 0.5 meter
+long, 0.1 broad, 0.005 deep can be bent seventy-four times without being
+broken. Subjected to friction, tin emits a characteristic odor.
+
+Tin in solution is largely used in electro-metallurgy for plating. Pure
+tin may be obtained by dissolving commercial tin in hydrochloric acid,
+by which it is converted into stannous chlorid; after filtering, this
+solution is evaporated to a small bulk, and treated with nitric acid,
+which converts it into stannic oxid, which in turn is thoroughly washed
+and dried, then heated to redness in a crucible with charcoal, producing
+a button of tin which is found at the bottom of the crucible.
+
+Pure tin may be precipitated in quadratic crystals by a slight galvanic
+current excited by immersing a plate of tin in a strong solution of
+stannous chlorid; water is carefully poured in so as not to disturb the
+layer of tin solution; the pure metal will be deposited on the plate of
+tin, at the point of junction of the water and metallic solution.
+
+In the study of tin as a material for filling teeth, we have deemed it
+expedient to consider some of its physical characteristics, in order
+that what follows may be more clearly understood.
+
+Tin possesses a crystallized structure, and can be obtained in
+well-formed crystals of the tetragonal or quadratic system (form right
+square prism), and on account of this crystalline structure, a bar of
+tin when bent emits a creaking sound, termed the "cry of tin;" the purer
+the tin the more marked the cry.
+
+The specific gravity is 7.29; electrical state positive; fusing point
+442 deg. F.; tensile strength per square inch in tons, 2 to 3. Tensile
+strength is the resistance of the fibers or particles of a body to
+separation, so that the amount stated is the weight or power required
+to tear asunder a bar of pure tin having a cross-section of one square
+inch.
+
+Tenacity: Iron is the most tenacious of metals. To pull asunder an iron
+wire 0.787 of a line in diameter requires a weight of 549 lbs. To pull
+asunder a gold wire of the same size, 150 lbs.; tin wire, 34 lbs.; gold
+being thus shown to be more than four times as tenacious as tin.
+(Fractions omitted.)
+
+Malleability: Pure tin may be beaten into leaves one-fortieth of a
+millimeter thick, thus requiring 1020 to make an inch in thickness.
+Miller states that it can be beaten into leaves .008 of a millimeter
+thick, thus requiring 3175 to make an inch in thickness. Richardson says
+that ordinary tin foil is about 0.001 of an inch in thickness.
+
+If the difficulty with which a mass of gold (the most malleable of
+metals) can be hammered or rolled into a thin sheet without being torn,
+be taken as one, then it will be four times as difficult to manipulate
+tin into thin sheets.
+
+Ductility: If the difficulty with which gold (the most ductile of
+metals) can be drawn be taken as one, then it will be seven times as
+difficult to draw tin into a wire. At a temperature of 212 deg. it has
+considerable ductility, and can be drawn into wire.
+
+Among the metals, silver is the best conductor of heat. If the
+conductivity of silver be taken as 100, then the conducting power of
+gold would be 53.2; tin, 14.5; gold being thus shown to be nearly four
+times as good a conductor of heat as tin. Among the metals, silver is
+the best conductor of electricity. If its electrical conductivity be
+taken at 100, then the conducting power of gold would be 77.96; tin,
+12.36; gold being thus shown to be more than six times as good a
+conductor of electricity as tin.
+
+Resistance to air: If exposed to dry, pure air, tin resists any change
+for a _great_ length of time, but if exposed to air containing moisture,
+carbonic acid, etc., its time resistance is reduced, although even then
+it resists corrosion much better than copper or iron.
+
+As to linear expansion, when raised from 32 deg. to 212 deg. F., aluminum
+expands the most of any of the metals. Taking its expansion as 1, that
+of tin would be 3, _i.e._, aluminum expands three times as much as tin.
+(Dixon, "Vade Mecum.")
+
+Solids generally expand equally in all directions, and on cooling return
+to their original shape. Within certain limits, metals expand uniformly
+in direct proportion to the increase in temperature, but the rate of
+expansion varies with different metals; thus, under like conditions, tin
+expands nearly twice (1-3/5) as much as gold, but the _rate_ of
+expansion for gold is nearly twice (1-7/10) that of tin.
+
+The capacity for absorbing heat varies with each metal; that of gold is
+about twice (1-3/4) that of tin.
+
+Tin has a scale hardness of about 4, on a scale of 12 where lead is
+taken as the softest and platinum the hardest. (Dixon, "Vade Mecum.")
+
+Tin has a scale hardness of about 2. (Dr. Miller.)
+
+To fuse a tin wire one centimeter in diameter requires a fusing current
+of electricity of 405.5 amperes. Up to 225 deg. C., the rise in resistance
+to the passage of an electric current is more rapid in tin than in gold.
+In some minerals the current follows the trend of the crystals.
+
+Gold wire coated with tin, and held in the flame of a Bunsen burner,
+will melt like a tin wire. At 1600 deg. to 1800 deg. tin boils and may be
+distilled.
+
+
+
+
+CHAPTER II.
+
+
+The largest and most complete dental library in the world is owned by
+Dr. H. J. McKellops, of St. Louis. Upon his cheerful invitation, the
+writer visited that "Mecca," and through his kindness and assistance a
+complete search was made, which resulted in obtaining a great portion of
+the following historical facts with reference to the use of tin in
+dentistry:
+
+"In 1783 I stopped a considerable decay in a large double under tooth,
+on the outside of the crown or near the gums, with fine tin foil, which
+lasted for a good number of years." ("A Practical and Domestic Treatise
+on Teeth and Gums," by Mr. Sigmond, Bath, England, 1825.)
+
+"Fine tin foil or gold leaf may be injected into a cavity successfully,
+and retained securely for many years." (Joseph Fox, Dover, England,
+1802.)
+
+"The statement has been made several times that tin foil was used in the
+United States for filling teeth as early as 1800, at which time
+dentistry began to be cultivated particularly as a science and art, and
+was beginning to be regarded as of more importance than it formerly had
+been. The writer has not found any record of its use in this country
+earlier than 1809. Tin may often be employed with entire confidence. I
+have seen fillings forty-one years old (made in 1809) and still perfect.
+Several molars had four or five plugs in them, which had been inserted
+at different periods during the last half-century. I prefer strips cut
+from six sheets laid upon each other. If the foil is well connected, the
+cut edges will adhere firmly; if they do not, the foil is not fit for
+use." (Dr. B. T. Whitney, _Dental Register of the West_, 1850.) First
+reference to the fact that tin is adhesive.
+
+"Tin is desirable in all unexposed cavities. It has a stronger affinity
+for acetic, citric, tartaric, malic, lactic, and nitric acids than the
+tooth has: a good material where the secretions are of an acid
+character, it is better that the filling should waste away than the
+tooth. One cavity in my mouth was filled with gold, decay occurred, the
+filling was removed; cavity filled with oxychlorid, which produced pain;
+filling removed; cavity filled with gutta-percha, still experienced
+pain; filling removed; cavity filled with tin, and pain ceased in an
+hour. A tin filling was shown in New York which was sixty years old;
+made in 1811." (Dr. E. A. Bogue, _British Journal of Dental Science_,
+1871.)
+
+"I have lately been removing tin pluggings (the juices of the mouth
+having oxidated and dissolved away the metal, so as to expose the teeth
+to decay) from teeth which I plugged fifteen years ago (1818) for the
+purpose of re-stopping with gold, and have in almost every instance
+found the bone of the tooth at the bottom of the pluggings perfectly
+sound and protected from decay." (J. R. Spooner, Montreal, 1833.)
+
+In 1800 the number of dentists in the United States was about one
+hundred, and many of them were using tin foil for filling teeth.
+
+In 1822 tin was employed by the best dentists, with hardly an exception;
+it grew in favor, especially for large cavities in molars, and for a
+cheaper class of operations than gold, but tin was not generally used
+until 1830. ("History of Dental and Oral Science in America.")
+
+"Lead, tin, and silver corrode and become more injurious than the
+original disease, and will in every case ultimately prove the cause of
+destruction to the tooth, which might have been preserved by proper
+treatment." (Leonard Koecker, 1826, and "New System of Treating the
+Human Teeth," by J. Paterson Clark, London, 1829 and 1830.)
+
+"Tin in situations out of reach of friction in mastication, as between
+two teeth, is like the tooth itself apt to be decomposed by acidity
+unless kept very clean." ("Practical and Familiar Treatise on Teeth and
+Dentism," J. Paterson Clark, London, 1836.) Refer to what the same
+author said in 1829.
+
+"Tin is used as a plugging material." ("The Anatomy, Physiology, and
+Diseases of the Teeth," by Thomas Bell, F.R.S., London, 1829.)
+
+"Silver and tin foil, although bright when first put in a cavity, very
+soon change to a dark hue, resembling the decayed parts of the teeth
+which are of a bluish cast; besides this, they are not sufficiently pure
+to remain in an unchanged state, and frequently they assist in the
+destruction of a tooth instead of retarding it." ("Familiar Treatise on
+the Teeth," by Joseph Harris, London, 1830.)
+
+"Tin is objectionable on account of rapid oxidation and being washed by
+the saliva into the stomach, as it may materially disorder it; the
+filling becomes so reduced that the cavity in which it has been inserted
+will no longer retain it, and acid fruits influence galvanic action."
+("Every Man his Own Dentist," Joseph Scott, London, 1833.)
+
+In 1836 Dr. Diaz, of Jamaica, used tin foil for filling teeth.
+
+"Gold is now preferred, though tin, from its toughness when in the leaf,
+is perhaps the most suitable. Americans are superior to British in
+filling." ("Plain Advice on Care of the Teeth," Dr. A. Cameron, Glasgow,
+1838.)
+
+[Illustration: FIG. 1.]
+
+[Illustration: FIG. 2.]
+
+"Tin foil is used for filling teeth." (S. Spooner, New York, 1838,
+"Guide to Sound Teeth.")
+
+In 1838 Archibald McBride, of Pittsburg, Pa., used tin for filling
+cavities of decay.
+
+The following facts were learned from Dr. Corydon Palmer: E. E. Smith,
+who had been a student of John and William Birkey, in Philadelphia, came
+to Warren, Ohio, in 1839, and among other things made the first gold
+plate in that part of the country. In operating on the anterior teeth,
+he first passed a separating file between them, excavated the cavity,
+and prepared the foil, _tin_ or gold, in tapes which were cut
+transversely, every eighth of an inch, about three-quarters of the way
+across. Fig. 1 shows the size of tape and the manner of cutting. With an
+instrument (Fig. 2) he drew the foil in from the labial surface, using
+such portion of the tape as desired.
+
+The instrument from which the illustration was made was furnished by Dr.
+Palmer, and is shown full size. Instruments for use on posterior teeth
+were short and strong, with as few curves as possible; no right and left
+cutters or pluggers were used, and none of the latter were serrated, but
+had straight, tapering round points, flat on the ends, and of suitable
+size to fill a good portion of the cavity. He used what was termed
+Abbey's chemically pure tin foil, forcing it in hard, layer upon
+layer,--as he expressed it, "smacked it up." In this manner he made tin
+fillings that lasted more than thirty years.
+
+In 1839 Dr. Corydon Palmer filled teeth with tin foil, also lined
+cavities with gold and filled the remainder with tin. In the same year
+he filled crown (occlusal) cavities one-half full with tin and the other
+half with gold, allowing both metals to come to the surface, on the same
+plan that many proximal cavities are now filled. (See Fig. 3, showing
+about one-half of the cavity nearly completed with tin cylinders. The
+same plan was followed when strips, or ropes, were used.)
+
+"I filled cavities about two-thirds full with tin, and finished with
+gold." (S. S. Stringfellow, _American Journal of Dental Science_, 1839.)
+
+"Tin foil is greatly used by some American dentists, but it is not much
+better than lead leaf." ("Surgical, Operative, and Mechanical
+Dentistry," L. Charles De Londe, London, 1840.)
+
+[Illustration: FIG. 3.]
+
+"In 1841 there were about twelve hundred dentists in the United States,
+many of whom were using tin, and there are circumstances under which it
+may be used not only with impunity, but advantage, but it is liable to
+change." (Harris.)
+
+"I put in tin fillings, and at the end of thirty years they were badly
+worn, but there was no decay around the margins." (Dr. Neall, 1843.)
+
+In 1843 Dr. Amos Westcott, of Syracuse, N. Y., filled the base of large
+cavities with tin, completing the operation with gold.
+
+"Tin is used in the form of little balls, or tubes, but folds are
+better; introduce the metal gradually, taking care to pack it so that it
+will bear equally upon all points; the folds superimpose themselves one
+upon the other; thus we obtain a successive stratification much more
+exact and dense, and it is impossible there can be any void." ("Theory
+and Practice of Dental Surgery," J. Lefoulon, Paris, 1844.)
+
+
+
+
+CHAPTER III.
+
+
+"Besides gold, the only material which can be used with any hope of
+permanent success is tin foil. Some dentists call it _silver_, and a
+tooth which cannot be filled with it cannot be filled with anything else
+so as to stop decay and make it last very long. It can be used only in
+the back teeth, as its dark color renders it unsuitable for those in
+front. When the general health is good, and the teeth little predisposed
+to decay, this metal will preserve them as effectually perhaps as gold;
+but where the fluids of the mouth are much disordered it oxidizes
+rapidly, and instead of preserving the teeth rather increases their
+tendency to decay." (Dr. Robert Arthur, Baltimore, 1845, "A Popular
+Treatise on the Diseases of the Teeth.")
+
+The false idea that a patient must have good health, normal oral fluids,
+and teeth little predisposed to decay, or else if filled with tin the
+decay would be hastened, originated with a German or English author, and
+has been handed down in works published since early in 1800. It even
+crept into American text-books as late as 1860, the authors of which now
+disbelieve it.
+
+"Tin undergoes but little change in the mouth, and may be used with
+comparative safety." ("Surgical, Mechanical, and Medical Treatment of
+the Teeth," James Robinson, London, 1846.)
+
+"Tin is soft, and can be easily and compactly introduced, but it is more
+easily acted on by the secretions of the mouth than gold and is less
+durable, but in the mouth of a healthy person _it will last for years_.
+Still, inasmuch as it cannot be depended on in _all_ cases, we are of
+the opinion that it should _never_ be employed." ("The Human Teeth,"
+James Fox, London, 1846.)
+
+The italics are ours. Every metal has a limited sphere of usefulness,
+and it should not be expected that tin will contend single-handed
+against all the complicated conditions which caries presents.
+
+"Of all the cheaper materials, I consider tin the best by far, and
+regard its use fully justifiable in deciduous teeth and in large
+cavities, as it is not every man who can afford the expense of nine
+leaves of gold and four hours of labor by a dentist on a single tooth."
+(Dr. Edward Taylor, _Dental Register of the West_, 1847.)
+
+"I consider tin good for any cavity in a chalky tooth: it will save them
+better than anything else." (Dr. Holmes, 1848.)
+
+"Tin can be used as a temporary filling, or as a matter of economy. It
+may be rendered impervious to air and dampness, but it corrodes in most
+mouths, unless it comes in contact with food in chewing, and then it
+rapidly wears away; it does not become hard by packing or under
+pressure, and that it forms a kind of a union with the tooth is
+ridiculous." (Dr. J. D. White, 1849, _Dental News Letter_.)
+
+"A tin plug will answer a very good purpose in medium and large cavities
+for six years. Much imposition has been practiced with it, and it is not
+made as malleable as it should and can be. An inferior article is
+manufactured which possesses brilliancy and resembles silver. This is
+often passed off for silver foil. No harm comes from this deception
+except the loss of the amount paid above the price for tin; but even
+this inferior tin foil is better than silver." ("The Practical Family
+Dentist," Dewitt C. Warner, New York, 1853.)
+
+"Tin made into leaves is employed as a stopping material; with
+sufficient experience it can be elaborated into the finest lines and
+cracks, and against almost the weakest walls, and teeth are sometimes
+lost with gold that might have been well preserved with tin. I saw an
+effective tin stopping in a tooth of Cramer's, the celebrated musical
+composer, which had been placed there thirty-five years ago by Talma,
+of Paris." ("The Odontalgist," by J. Paterson Clark, London, 1854.)
+
+Refer to what the same author said in 1836.
+
+"Tin is the best substitute for gold, and can often be used in badly
+shaped cavities where gold cannot." (Prof. Harris, 1854.)
+
+"Tin is better than any mixture of metals for filling teeth." (Professor
+Tomes, London, 1859.)
+
+In 1860 a writer said that "such a change may take place in the mouth as
+to destroy tin fillings which had been useful for years, and that tin
+was not entirely reliable in any case; it must not be used in a tooth
+where there is another metal, nor be put in the bottom of a cavity and
+covered with gold, for the tin will yield, and when fluids come in
+contact with the metals, chemical action is induced, and the tin is
+oxidized. Similar fillings in the same mouth may not save the teeth
+equally well. Filling is predicated on the nature of decay, for only on
+correct diagnosis can a proper filling-material be selected."
+
+Reviewing the foregoing statement, we believe that a change may take
+place in the mouth which will destroy gold fillings (or the
+tooth-structure around them) much oftener than those of tin. It is now
+every-day practice to put tin into the same tooth with another metal; if
+the bottom of a cavity is filled with tin properly packed, it will not
+yield when completed with gold, and if the gold is tight, the oral
+fluids cannot come in contact with both metals and produce chemical
+action or oxidation; similar fillings of gold in the same mouth do not
+save the teeth equally well. Should we expect more of tin in this
+respect, or discard it because it is not always better than gold?
+
+In Article V of the "New Departure Creed," Dr. Flagg says, "Skillful and
+scrupulous dentists fill with tin covered with gold, thereby preventing
+decay, pulpitis, death of the pulp, and abscess, and thus save the
+teeth."
+
+In 1862 Mr. Hockley, of London, mentions tin for filling, and the same
+year Dr. Zeitman, of Germany, recommended it as a substitute for gold,
+particularly for poor people.
+
+"Is tin foil poisonous? If not, why are our brethren so reluctant to use
+it? Is it nauseous? If not, why not employ it? Will it not preserve the
+teeth when properly used? Then why not encourage the use of it? Does its
+name signify one too common in the eyes of the people, on account of its
+daily use in the tin shops, or do patients murmur when the fee is
+announced, because it is nothing but tin? Is it not better than amalgam,
+although the patient may believe it less costly? Eleven good plugs,
+twenty-nine years old, in one mouth demonstrates that tin will last as
+long as gold in many cases." (F. A. Brewer, _Dental Cosmos_, 1863.)
+
+"So much tin foil is used for personal and domestic purposes that the
+following is important: Ordinary tin foil by chemical analysis contained
+88.93 per cent. of lead; embossed foil, 76.57 per cent.; tea foil, 88.66
+per cent.; that which was sold for the pure article, 34.62 per cent. Tin
+foil of above kind is made by inclosing an ingot of lead between two
+ingots of tin, and rolling them out into foil, thus having the tin on
+the outside of the lead." (Dr. J. H. Baldock, _Dental Cosmos_, 1867.)
+
+The author used tin foil for filling the teeth of some of his
+fellow-students at the Ohio College of Dental Surgery in 1867.
+
+"Amalgam should never be used in teeth which can be filled with tin, and
+most of them can be." (Dr. H. M. Brooker, Montreal, 1870.)
+
+"I have used tin extensively, and found it more satisfactory than
+amalgam. Dentists ignore tin, because it is easier to use amalgam, less
+trouble. This is not right. If your preceptor has told you that amalgam
+is as good as tin, and he thinks so, let him write an article in its
+defense. Not one dentist in ten who has come into the profession within
+the last ten years knows how to make a tin filling, and only a few of
+the older ones know how to make a _good_ one." (Dr. H. S. Chase,
+_Missouri Dental Journal_, 1870.)
+
+"Among the best operators a more general use of tin would produce
+advantageous results, while among those whose operations in gold are not
+generally successful an almost exclusive use of tin would bring about a
+corresponding quantum of success to themselves and patients, as against
+repeated failures with gold. The same degree of endeavor which lacked
+success with gold, if applied to tin would produce good results and save
+teeth. A golden shower of ducats realized for gold finds enthusiastic
+admirers, but a dull gray shower for tin work is not so admirable, even
+though many of the teeth were no better for the gold as gold, nor so
+well off in the ultimate as with tin." (Dr. E. W. Foster, _Dental
+Cosmos_, 1873.)
+
+In 1873 Dr. Royal Varney said, "I am heartily in favor of tin; it is too
+much neglected by our first-class operators."
+
+"Tin stops the ends of the tubuli and interglobular spaces which are
+formed in the teeth of excessive vascular organization; if more teeth
+were filled with tin, and a smaller number with futile attempts with
+gold, people would be more benefited." (Dr. Castle, _Dental Cosmos_,
+1873.)
+
+"If cavities in teeth out of the mouth are well filled with tin, and put
+into ink for three days, no discoloration of the tooth (when split open)
+can be seen." (W. E. Driscoll, _Dental Cosmos_, 1874.)
+
+"Tin makes an hermetical filling, and resists the disintegrating action
+of the fluids of the mouth. If an operator can preserve teeth for
+fifteen dollars with tin, which would cost fifty dollars with gold,
+ought he not to do so? Upon examination of the cavities from which
+oxidized plugs have been removed, these oxids will be found to have had
+a reflex effect upon the dentin; the walls and floors will be discolored
+and thoroughly indurated, and to a great degree devoid of sensitiveness,
+although they were sensitive when filled. Tin is valuable in case of
+youth, nervousness, impatience, high vitality of dentin, low
+calcification, and low pecuniosity." (Dr. H. Gerhart, _Pennsylvania
+Journal of Dental Science_, 1875.)
+
+"Tin Foil for Filling Teeth." Essay by Dr. H. L. Ambler, read before the
+Ohio State Dental Society. (_Dental Register of the West_, 1875.)
+
+"Some say that if tin is the material the cavity must be filled with,
+that it must be filled entirely with it, but advanced teachings show
+differently." (Dr. D. D. Smith, _Dental Cosmos_, October, 1878.)
+
+"Frail teeth can be saved better with tin than with gold. I never saw a
+devitalized pulp under a tin filling." (Dr. Dixon, _Dental Cosmos_, May,
+1880.)
+
+"Tin may be used as a base for proximate fillings in bicuspids or
+molars, in third molars, in children's permanent molars, in the
+temporary teeth, and in any cavity where the filling is not
+conspicuous." (Dr. A. W. Harlan, _Independent Practitioner_, 1884.)
+
+"Tin in blocks, mats, and tapes is used like non-cohesive gold foil, but
+absence of cohesion prevents the pieces from keeping their place as well
+as the gold." ("American System of Dentistry," 1887.)
+
+This is virtually saying that there is cohesion of non-cohesive gold,
+and that for this reason it keeps its place better than tin. It has
+always been supposed that there was no cohesion of layers of
+non-cohesive gold, and as the tin is used on the non-cohesive plan,
+therefore one keeps its place as well as the other. We claim that
+generally in starting a filling, tin will keep its place better than
+cohesive or non-cohesive gold, because it combines some of the
+cohesiveness of the former with the adaptability of the latter.
+
+"Tin will save teeth in many cases as well or better than gold. Put a
+mat of tin at the cervical wall of proximate cavities in molars and
+bicuspids, and it makes a good filling which has a therapeutic effect on
+tooth-structure that prevents the recurrence of caries, probably because
+the infiltration of tin oxid into the tubuli is destructive to animal
+life. Where the filling is not exposed to mechanical force, there is no
+material under heavens which will preserve the teeth better." (Dr.
+Beach, _Dental Cosmos_, 1889.)
+
+"I extracted a tooth in which I found a cavity of decay which had
+extended toward a tin filling, but stopped before reaching it; on
+examining the tooth-structure between the new cavity and the tin
+filling, it was found to be very hard, indicating apparently that there
+had been some action produced by the presence of the tin." (Dr. G.
+White, _Dental Cosmos_, 1889.)
+
+"Pure tin in form of foil is used as a filling and also in connection
+with non-cohesive gold." (Mitchell's "Dental Chemistry," 1890.)
+
+"Tin ranks next to gold as a filling-material." (Essig's "Dental
+Metallurgy," 1893.)
+
+"Tin is good for children's teeth, when gold or amalgam is not
+indicated. It can be used in cavities which are so sensitive to thermal
+changes as to render the use of gold or amalgam unwise, but it can only
+be used in cavities with continuous walls, and should be introduced in
+the form of cylinders or ropes, with wedge-shaped pluggers having sharp
+deep serrations, thus depending upon the wedging or interdigitating
+process to hold the filling in the cavity." ("Operative Technics," Prof.
+T. E. Weeks, 1895.)
+
+"Tin for filling teeth has been almost superseded by amalgam, although
+among the older practitioners (those who understand how to manipulate
+it) tin is considered one of the best, if not the very best metal known
+for preserving the teeth from caries. In consequence of its lack of the
+cohesive property, it is introduced and retained in a cavity upon the
+wedging principle, the last piece serving as a keystone or anchor to the
+whole filling. Each piece should fill a portion of the cavity from the
+bottom to the top, with sufficient tin protruding from the cavity to
+serve for thorough condensation of the surface, and the last piece
+inserted should have a retaining cavity to hold it firmly in place. The
+foil is prepared by folding a whole or half-sheet and twisting it into a
+rope, which is then cut into suitable lengths for the cavity to be
+filled." (Frank Abbott, "Dental Pathology and Practice," 1896.)
+
+"Forty-three years ago, for a young lady fourteen years of age, I
+filled with non-cohesive gold all the teeth worth filling with this
+metal; the rest I filled with tin. Three years after that there was not
+a perfect gold filling among the whole number, and yet the tin fillings
+were just as good as when made. The explanation as to why the tin
+fillings lasted so much longer than the gold ones was, that there must
+have been something in the tin that had an affinity for the teeth and
+the elements that formed the dentin, by which some compound was formed,
+or else it must have been in the adaptation." (Dr. H. Gerhart, _Dental
+Cosmos_, January, 1897.)
+
+
+
+
+CHAPTER IV.
+
+
+At the World's Columbian Dental Congress, held in Chicago, August, 1893,
+the author presented an essay on "Tin Foil for Filling Teeth."
+
+During the discussion of the subject, the following opinions were
+elicited:
+
+Dr. E. T. Darby: "I have always said that tin was one of the best
+filling-materials we have, and believe more teeth could be saved with it
+than with gold. I have restored a whole crown with tin, in order to show
+its cohesive properties; the essayist has paid a very high and worthy
+tribute to tin."
+
+Dr. R. R. Freeman: "I have used tin foil for twenty-five years, and know
+that it has therapeutic properties, and is one of the best
+filling-materials, not excepting gold."
+
+Madam Tiburtius-Hirschfield: "I heartily indorse the use of tin, and
+have tested its cohesive properties by building up crowns."
+
+Dr. A. H. Brockway: "I am a strong believer in the use of tin, on
+account of its adaptability, and the facility with which saving fillings
+can be made with it."
+
+Dr. Gordon White: "After having used tin for nine years, I claim that
+it is the best filling-material that has been given to our profession."
+
+Dr. C. S. Stockton: "Tin is one of the best materials for saving teeth,
+and we should use it more than we do."
+
+Dr. James Truman: "I use tin strictly upon the cohesive principle, and
+would place it in all teeth except the anterior ones, but would not
+hesitate to fill these when of a chalky character."
+
+Dr. Corydon Palmer: "For fifty-four years I have been a firm advocate of
+the use of tin, and I have a filling in one of my teeth which is forty
+years old."
+
+Dr. William Jarvie: "I rarely fill a cavity with gold for children under
+twelve years of age that I want to keep permanently, but use tin, and in
+five or ten years, more or less, it wears out. Still, it can easily be
+renewed, or if all the tin is removed we find the dentin hard and firm.
+The dentist is not always doing the best for his patients if he does not
+practice in this way."
+
+Dr. C. E. Francis: "I have proved positively that tin foil in good
+condition is cohesive, and my views have been corroborated by dentists
+and chemists."
+
+Dr. James E. Garretson: "Tin foil is cohesive, and can be used the same
+as gold foil, and to an extent answers the same purpose."
+
+Dr. C. R. Butler: "Tin is cohesive and makes a first-class saving
+filling."
+
+Dr. W. C. Barrett: "Tin is as cohesive as gold, and if everything was
+blotted out of existence with which teeth could be filled, except tin,
+more teeth would be saved."
+
+Dr. L. D. Shepard: "Tin possesses some antiseptic properties for the
+preservation of teeth that gold does not."
+
+Dr. W. D. Miller: "I use tin foil in cylinders, strips, and ropes, on
+the non-cohesive plan, but admit that it possesses a slight degree of
+cohesiveness, and when necessary can be built up like cohesive gold by
+using deeply serrated pluggers."
+
+Dr. Benjamin Lord says, "It is said that we know the world, or learn the
+world, by comparison. If we compare tin foil with gold foil, we find
+that the tin, being softer, works more kindly, and can be more readily
+and with more certainty adapted to the walls, the inequalities, and the
+corners of the cavities.
+
+"We find also that tin welds--mechanically, of course--more surely than
+soft gold, owing to its greater softness; the folds can be interlaced or
+forced into each other, and united with more certainty, and with so
+much security that, after the packing and condensing are finished, the
+mass may be cut like molten metal.
+
+"I contend moreover that for contouring the filling or restoring the
+natural shape of the teeth, where there are three walls remaining to the
+cavity, tin is fully equal to gold, and in some respects even superior;
+as tin can be secured, where there is very little to hold or retain the
+filling, better than gold, owing to the ease and greater certainty of
+its adaptation to the retaining points or edges of the cavity.
+
+"It will be said, however, that tin fillings will wear away. The
+surfaces that are exposed to mastication undoubtedly will wear in time;
+but the filling does not become leaky if it has been properly packed and
+condensed, nor will the margins of the cavity be attacked by further
+decay on that account.
+
+"Altogether, I believe that we can make more perfect fillings with tin
+than we can with gold, taking all classes of cavities; but it must not
+be understood that it is proposed that tin should ever take the place of
+gold where the circumstances and conditions indicate that the latter
+should be used. Of course, the virtue is not in the gold or the tin, but
+in the mechanical perfection of the operation, and tin having more
+plasticity than gold, that perfection can be secured with more ease and
+certainty.
+
+"If we compare tin with amalgam, we must certainly decide in favor of
+the former and give it preference; as if it is packed and condensed as
+perfectly as may be, we know just what such fillings will do every time.
+We know that there will be no changes or leakage of the fillings at the
+margins; whereas, with amalgam, the rule is shrinkage of the mass, and
+consequently the admission of moisture around the filling, the result
+being further decay. It is not contended that this is always the result
+with amalgam, but it is the general rule; yet we must use amalgam, as
+there are not a few cases where it is the best that we can do; but it is
+to be hoped, and I think it may be said, that as manipulative skill
+advances, amalgam will be less and less used. For so-called temporary
+work, very often I prefer tin to gutta-percha, as it makes a much more
+reliable edge and lasts longer, even when placed and packed without
+great care."--_N. Y. Odon. Society Proceedings_, page 51, 1894.
+
+One of the main reasons which induced the writer to begin the use of tin
+foil (_Stannum Foliatum_) for filling teeth, in 1867, was the fact that
+amalgam filling failures were being presented daily. Believing that tin
+could do no worse, but probably would do better, we banished amalgam
+from the office for the succeeding seven years, using in the place of
+it tin, oxychlorid, and gutta-percha. Since that time we have seen no
+good reason for abandoning the use of tin, as time has proved it worthy
+of great confidence. There is no better dental litmus to distinguish the
+conservative from the progressive dentist.
+
+If we take a retrospective view and consider what tin foil was thirty
+years ago, we do not wonder that so many operators failed to make tight,
+good-wearing fillings. As it came from the manufacturer it looked fairly
+bright, but after being exposed to the air for a short time it assumed a
+light brassy color, and lost what small amount of integrity it
+originally possessed. This tin was not properly refined before beating,
+or something was put on the foil while beating, so that it did not have
+the clean, bright surface and cohesive quality which our best foil now
+has. No. 4 was commonly used, but it would cut and crumble in the most
+provoking manner. Fillings were made by using mats, cylinders, tapes,
+and ropes, with hand-pressure, on the plan for manipulating non-cohesive
+gold foil, but it was difficult to insert a respectable approximal
+filling.
+
+From the best information obtainable, the writer believes that Marcus
+Bull (the predecessor of Abbey) was the first to manufacture and sell
+tin foil in the United States, as he began the manufacture of gold foil
+at Hartford in 1812.
+
+Several years ago a radical change came about in the preparation of tin
+foil, for which the manufacturer should have his share of the credit,
+even if the dentist did ask for something better, for the quality
+depends largely upon the kind and condition of the tin used and on the
+method of manufacture.
+
+For making tin foil for filling teeth, the purest Banca tin that can be
+obtained is used. The tin is melted in a crucible under a cover of
+powdered charcoal. It is then cast into a bar and rolled to the desired
+thickness, so that if No. 6 foil is to be made, a piece one and one-half
+(1-1/2) inches square would weigh nine grains. This ribbon is then cut
+into lengths of about four feet, and spread on a smooth board slanted,
+so that the end rests in a vat of clean water.
+
+Then apply to the exposed surface of the ribbon diluted muriatic acid,
+and immediately wash with a strong solution of ammonia. Turn the ribbon
+and treat the other side in the same way. It is then washed and rubbed
+dry. The object of using the acid is to remove stains and whiten the
+tin, and the ammonia is used to neutralize the effect of the acid.
+
+The strips are then cut into pieces one and a half inch square, filled
+into a cutch and beaten to about three inches square. It is then removed
+from the cutch and filled into a mold, and further beaten to the desired
+size. When the ragged edges are trimmed off, the foil is ready for
+booking.
+
+It takes skill and experience to beat tin foil, for it is not nearly as
+malleable as gold; up to No. 20 it is usually beaten, but higher numbers
+are prepared by rolling. In each case the process is similar to that
+employed in preparing gold foil. The number on the book is supposed to
+indicate the weight or thickness of the leaf. On the lower numbers the
+paper of the book leaves its impression.
+
+On weighing sheets of tin foil from different manufacturers a remarkable
+discrepancy was found between the number on the book and the number of
+grains in a sheet, viz: Nos. 3, 4, 5, weighed 7 gr. each; No. 6, 9 gr.;
+No. 8, from 9 to 18 gr.; No. 10, from 14 to 15 gr.; No. 20, 18 gr. In
+some instances the sheets in the same book varied three grains. We
+submit that it would be largely to the advantage of both manufacturer
+and dentist to have the number and the grains correspond. No dentist
+wishes to purchase No. 8 and find that he has No. 18; no one could sell
+gold foil under like circumstances. Of the different makes tested,
+White's came the nearest to being correct. The extra tough foil which
+can now be obtained is chemically pure, and with it we can begin at the
+base of any cavity, and with mallet or hand force produce a filling
+which will be one compact mass, so that it can be cut and filed; yet in
+finishing, it will not bear so severe treatment as cohesive gold. Always
+handle tin foil with clean pliers, never with the fingers; and prepare
+only what is needed for each case, keeping the remainder in the book
+placed in the envelope in which it is sold, otherwise extraneous matter
+collects upon it, and it will oxidize _slightly_ when exposed to the air
+for a _great_ length of time.
+
+Before using tin foil, a few prefer to thoroughly crumple it in the
+hands or napkin, under the impression that they thus make it more
+pliable and easier to manipulate.
+
+A piece of blue litmus paper moistened and moved over a sheet of tin
+foil will occasionally give an acid reaction, probably owing to the acid
+with which it is cleaned before beating not having been thoroughly
+removed. Foil held under the surface of distilled water and boiled for
+five minutes, then left until the water is cold, removed and dried,
+shows it has been annealed, which makes it work easily, but not as hard
+a filling can be made from it as before boiling.
+
+In selecting and using this material for filling, we are able fully to
+protect the cavity; and if we understand the material, and how to
+manipulate it, we will surely succeed. This statement demands serious
+attention, and appeals to every one who is anxious to practice for the
+best interests of his patients; then let us make a thorough study of the
+merits of the method and material.
+
+Until recently, the term cohesion had but one special meaning to
+dentists, and that as applied to gold for filling teeth; being
+understood as the property by which layers of this metal could be united
+without force so as to be inseparable. The writer claims that good tin
+foil in proper condition is cohesive when force is applied, and can be
+used for filling teeth in the same manner in which cohesive gold foil is
+used. This claim has been confirmed by several dentists, as noted in
+another part of this volume.
+
+Cohesion is the power to resist separation, and it acts at insensible
+distances. The integral particles of a body are held together by
+cohesion, the constituent parts are united by affinity.
+
+The attraction between atoms of pure tin represents cohesion. Marble is
+composed of lime and carbonic acid, which are united and held together
+by affinity.
+
+The condition which obtains in the tin may be called cohesion, adhesion,
+welding, or interdigitation, but the fact remains that layers of tin
+foil can be driven together into a solid mass, making a tight filling
+with less malleting than is required for gold; if it is overmalleted,
+the receiving surface is injured.
+
+On account of its pliability it is easily adapted to the walls and
+margins, and a perfect fit is made, thus preventing capillary action and
+preventing further caries. Of all the metals used for filling it is the
+best tooth-preserver and the most compatible with tooth-substance, and
+the facility with which a saving filling can be made largely commends
+it.
+
+Tin has great possibilities, and has already gained a high position as a
+filling-material. Upon the knowledge we possess of the possibilities and
+limitations of tin as a filling-material, and our ability to apply that
+knowledge, will largely depend our success in preserving teeth.
+
+It is a good material for filling many cavities in the temporary teeth,
+and children will bear having it used, because it can be placed quickly,
+and but little force is required to condense one or two layers of No. 10
+foil. The dentin in young teeth has a large proportion of organic
+material, for which reason, if caries takes place, many believe it is
+hastened by thermal changes. Gold fillings in such teeth might prevent
+complete calcification, on account of the gold being so good a
+conductor; but if tin is used, there is much more probability of
+calcification taking place, because of its low conductivity and its
+therapeutic influence. It does not change its shape after being packed
+into a cavity. Under tin, teeth are calcified and saved by the deposit
+of lime-salts from the contents of the dentinal tubuli. This is termed
+progressive calcification.
+
+Like other organs of the human body, the teeth are more or less subject
+to constitutional change. The condition in which we find tooth-structure
+which needs repairing or restoring should be a sure indicator to us in
+choosing a filling-material. Up to the age of fourteen, and sometimes
+later, we find many teeth which are quite chalky. In some mouths also,
+at this period, the fluids are in such a condition that oxychlorid and
+oxyphosphate do not last long; for some reason amalgam soon fails, while
+gutta-percha is quickly worn out on an occlusal surface. In all such
+cases we recommend tin, even in the anterior teeth, for as the patient
+advances in years the tooth-structure usually becomes more dense, so
+that, if desirable, the fillings can be removed, and good saving
+operations can be made with gold. By treating cases in this manner very
+little, if any, tooth-structure is lost.
+
+The teeth of the inhabitants of Mexico and Guatemala are characteristic
+of their nervous and nervo-lymphatic temperaments; children ten years of
+age often have twenty-eight permanent teeth, and they are generally soft
+or chalky, but our dentists there report good success in saving them
+with tin.
+
+In filling this class of teeth, we should be very careful not to use
+force enough to injure the cavity-margin, for if this occurs, a leaky
+filling will probably be the result. Still, we have seen some cases
+where _slight_ imperfections at the margin, which occurred at the time
+of the filling or afterward, did no harm, because the deposit of tin
+oxid filled up the ends of the tubuli, thus preventing caries. We
+believe that this bar to the progress of caries is set up more
+frequently when tin is used than with any other metal under like
+conditions.
+
+
+
+
+CHAPTER V.
+
+
+In some mouths tin does not discolor, but retains a clean, unpolished
+tin color, yet when there is a sesquioxid of the metal formed, fillings
+present a grayish appearance. In the same mouth some fillings will be
+discolored, while others are not. As a general rule, proximal fillings
+are most liable to show discoloration. Perhaps one reason is that on
+occlusal and buccal surfaces they are subject to more friction from
+mastication, movements of the cheeks, and the use of the brush.
+
+We have seen a large number of fillings which were not blackened, yet
+were saving the teeth perfectly, thus proving to a certainty that
+blackening of tin in the tooth-cavity is not absolutely essential in
+order to obtain its salvatory effects as a filling-material.
+
+Where there is considerable decomposition of food which produces
+sulfuretted hydrogen, the sulfid of tin may be formed on and around the
+fillings; it is of a yellowish or brownish color, and as an antiseptic
+is in such cases desirable. To offset the discoloration, we find that
+the sulfid is insoluble, and fills the ends of the tubuli, thus lending
+its aid in preventing further caries. A sulfid is a combination of
+sulfur with a metal or other body. A tin solution acted on by
+sulfuretted hydrogen (H_{2}S) produces a dark-brown precipitate (SnS),
+stannous salt, which is soluble in ammonium sulfid (NH_{4})_{2}S_{2};
+this being precipitated, gives (SnS_{2}) stannic salt, which is yellow.
+Brown precipitates are formed by both hydrogen sulfid and ammonium
+sulfid, in stannous solutions. Yellow precipitates are formed by
+hydrogen sulfid and ammonium sulfid in stannic solutions. The yellow
+shade is very seldom seen on tin fillings; the dark brown is more
+common.
+
+An oxid is a combination of oxygen with a metal or base destitute of an
+acid. In oxidation the oxygen that enters into combination is not
+sufficient to form an acid. The protoxid of tin (SnO) is black, and can
+be obtained from chlorid of tin, or by _long_ exposure of tin to the
+atmosphere. The oxygen in the saliva helps to blacken the tin, and the
+metallic oxid penetrates the dentin more or less, acting as a
+protection, because it is insoluble. Oxygen is the only element which
+forms compounds with all others, and is the type of electro-negative
+bodies; it combines with all metals, therefore with tin, and in many
+cases only the metal is discolored, and not the tooth. Steam boilers are
+made tight by oxidation.
+
+Where there is complete oxidation, the tooth is blackened to but a very
+slight depth, and the oxid fills the ends of the tubuli, thus affording
+an additional barrier to the entrance of caries. The filling itself will
+prevent caries, but oxidation acts as an assistant.
+
+"In the mouth, a suboxid is more likely to be formed than a protoxid,
+but both are black; sulfur and oxygen are capable of acting on tin under
+favorable circumstances, such as warmth, moisture, full contact,
+condensation of elements, and their nascent conditions; the first three
+are always present in the mouth. The protosulfuret of tin is black."
+(Dr. George Watt.) Others give the color as bluish-gray, nearly black.
+
+Experiments show that slight galvanic currents exist between fillings of
+dissimilar metals in the mouth, and practical experience demonstrates
+that these currents occasionally produce serious results.
+
+Direct galvanic currents do not decompose normal teeth by true
+electrolysis, but acids resulting from decomposition of food and fluids
+react upon the lime constituents of the teeth and promote secondary
+caries.
+
+When two metals are so situated in the mouth that the mucous membrane
+forms a connecting conductor and the fluids are capable of acting on
+one metal, galvanic action is established sufficient to decompose any of
+the binary compounds contained in these fluids; the liberated nitrogen
+and hydrogen form ammonia, which being exposed to the action of oxygen
+is decomposed and nitric oxid formed, resulting in nitric acid. We also
+have in the mouth air, moisture, and decomposing nitrogenous food to
+assist in the production of nitric acid.
+
+"Galvanic action is more likely to develop hydrochloric acid, for the
+chlorids of sodium and potassium are present in the normal saliva and
+mucus, and when decomposed their chlorin unites with the hydrogen
+derived from the water of the saliva." (Dr. George Watt.)
+
+The fact should also be noted that both nitric and hydrochloric acids
+are administered as medicine, and often assist in producing decay.
+
+When there is a battery formed in a mouth containing tin fillings and
+gold fillings, and the fluids of the mouth are the exciting media, tin
+will be the positive element and gold the negative element; thus when
+they form the voltaic pair, the tin becomes coated or oxidized and the
+current practically ceases.
+
+There is more or less therapeutical and chemical action in cavities
+filled with tin, and its compatibility and prophylactic behavior as a
+filling-material depends partly upon the chemical action which occurs.
+
+Some dentists fill sensitive cavities with tin, in order to secure
+gentle galvanic action, which they believe to be therapeutic,
+solidifying the tooth-structure.
+
+"Tin possesses antiseptic properties which do not pertain to gold for
+arresting decay in frail teeth; it not only arrests caries mechanically,
+but in chalky (imperfect) structure acts as an antacid element in
+arresting the galvanic current set up between the tooth-structure and
+filling-material." (Dr. S. B. Palmer.) If the metal is acted on, the
+tooth is comparatively safe; if the reverse, it is more or less
+destroyed. The galvanic taste can be produced by placing a piece of
+silver on the tongue and a steel pen or piece of zinc under it; then
+bring the edges of the two pieces together for a short time, rinse the
+saliva around in the mouth, and the peculiar flavor will be detected.
+
+"In 1820 attention was called to the injurious effects of the galvanic
+current on the teeth, and dentists were advised never to use tin and
+amalgam in the same mouth.
+
+"A constant galvanic action is kept up in the mouth when more than one
+kind of metal is used in filling teeth, and galvanism is often the
+cause of extensive injury to the teeth. The most remarkable case I ever
+saw was that of a lady for whom I filled several teeth with tin. After a
+time decay took place around some of the fillings. I removed them and
+began to refill, but there was so much pain I could not proceed. I found
+that by holding a steel plugger an inch from the tooth I could give her
+a violent galvanic shock. I observed that the exhalation of the breath
+increased the evolution of galvanism." (Dr. L. Mackall, _American
+Journal of Dental Science_, 1839.)
+
+"When a faulty tooth in the upper jaw had been stopped from its side
+with tin, the interstice between it and the adjoining tooth being quite
+inconsiderable, while the upper surface of a tooth not immediately
+beneath it in the lower jaw was stopped with the same metal, I have
+known a galvanic shock regularly communicated from one tooth to the
+other when by the movement of jaws or cheeks they were brought near
+together." (Dr. E. Parmly, _American Journal of Dental Science_, 1839.)
+
+"An interesting debate here sprung up on the action where two metals are
+used in one filling, such as gold and tin, the saliva acting as a
+medium, and where the baser metal is oxidized by exhalents and by
+imbibition through the bony tooth-structure." (Pennsylvania Society of
+Dental Surgeons, 1848.)
+
+"A patient came to me and complained of pain in the teeth. Upon
+examination I found an amalgam filling next to one of tin. With a file I
+made a V-shaped separation, when they experienced immediate relief from
+pain." (Dr. Nevill, _American Journal of Dental Science_, 1867.)
+
+In regard to the decay of teeth being dependent on galvanic action
+present in the mouth, Dr. Chase, in 1880, claimed that a tooth filled
+with gold would necessarily become carious again at the margin of the
+cavity, wherever the acid secretions constantly bathe the filling and
+tooth-substance. A tooth filled with amalgam succumbs to this
+electro-chemical process less rapidly, while one filled with tin still
+longer escapes destruction. The comparative rapidity with which teeth
+filled with gold, amalgam, or tin, are destroyed is expressed by the
+numbers 100, 67, 50. He prepared pieces of ivory of equal shape and
+size, bored a hole in each, and filled them. After they had been exposed
+to the action of an acid for one week, they had decreased in
+weight,--viz, piece filled with gold, 0.06; amalgam, 0.04; tin, 0.03.
+
+"With tin and gold, some have the superstition that the electricity
+attendant upon such a filling will in some way be injurious to the
+tooth; it matters not which is on the outside, when rolled and used as
+non-cohesive cylinders each appears. We say that neither experimentally,
+theoretically, nor practically can any good or bad result be expected
+from the electrical action of a tin-gold filling on tooth-bone, and
+neither will the pulp be disturbed." (Dr. W. D. Miller, _Independent
+Practitioner_, August, 1884.)
+
+"When the bottom of a cavity is filled with tin which is tightly
+(completely) covered with gold, there is _practically_ no galvanic
+action and there is no current generated by contact of tin and
+gold,--_i.e._, no current leaves the filling to affect the dentin. That
+portion of tin which forms the base is more positive than a full tin
+filling would be. The effect is to cause the surface exposed to dentin
+to oxidize more than tin would do alone; in that there is a benefit. In
+very porous dentin there is enough moisture to oxidize the tin, by
+reason of the current set up by the gold." (Dr. S. B. Palmer.)
+
+Electricity generated by heat is called thermo-electricity. If a cavity
+with continuous walls is half filled with tin and completed with gold,
+or half filled with silver and completed with gold, and the junctions of
+the metal are at 20-1/2 deg. C. and 19-1/2 deg. C., if the electrical action
+between the tin and gold be 1.1, the action between the silver and gold
+will be 1.8, thus showing the action in silver and gold to be nearly
+two-thirds more than in the tin and gold, a deduction which favors the
+tin and gold.
+
+Rubbing two different substances together is a common method of
+producing an electric charge. Is there not more electricity generated
+during mastication on metal fillings than when the jaws are at rest?
+Friction brings into close contact numerous particles of two bodies, and
+perhaps the electrical action going on more or less all the time through
+gold fillings (especially when other metals are in the mouth) accounts
+for a powdered condition of the dentin which is sometimes found under
+cohesive gold fillings, but not under tin.
+
+
+
+
+CHAPTER VI.
+
+
+White caries, the most formidable variety known, may be produced by
+nitric acid, and in these cases all the components of the tooth are
+acted upon and disintegrated as far as the action extends. In proximal
+cavities attacked by this kind of caries, separate freely on the lingual
+side, and fill with tin. When such fillings have been removed the dentin
+has been found somewhat discolored and greatly solidified as compared to
+its former condition; this solidification or calcification is more
+frequent under tin than gold, which is partly due to the tin as a poor
+conductor of heat. Nature will not restore the lost part, but will do
+the next best thing--solidify the dentin. In some cases, under tin, the
+pulp gradually recedes, and the pulp-cavity is obliterated by secondary
+dentin. In other cases the pulps had partly calcified under tin. It has
+been known for years that tin would be tolerated in large cavities very
+near the pulp without causing any trouble, and one reason for this is
+its low conducting power. Attention is called to the fact that gold is
+nearly four times as good a conductor of heat as tin, and more than six
+times as good a conductor of electricity. Where tin fillings are
+subject to a large amount of attrition, they wear away sooner or later,
+but this is not such a great detriment, for they can easily be repaired
+or replaced, and owing to the concave form produced by wear the patient
+is liable to know when a large amount has been worn away. That portion
+against the wall of the cavity is the last removed by wear, so that
+further caries is prevented so long as there is any reasonable amount of
+tin left. If at this time the tooth has become sufficiently solidified,
+proper anchorage can be cut in the tin or tooth, one or both, as
+judgment dictates, and the filling completed with gold. A tin filling,
+confined by four rather frail walls, may condense upon itself, but it is
+so soft and adaptable that the force which condenses it continually
+secures the readaptation at the margin; thus there will be no leakage or
+caries for years. Owing to its softness and pliability, it may be driven
+into or onto the tubuli to completely close them from outside moisture,
+and with a hand burnisher the tin can be made to take such a hold on
+dry, rough tubuli that a cutting instrument is necessary to remove all
+traces of it.
+
+Tin foil has been found in the market that under a magnifying glass
+showed innumerable tiny black specks, which, upon being touched with an
+instrument, crumbled away, leaving a hole through the foil. More than
+likely, some of the failures can be attributed to the use of such foil.
+Good tough foil, well condensed by hand or mallet force, stays against
+the walls of a cavity and makes a tight filling, and ought to be called
+as near perfect as any filling, because it preserves the tooth, and
+gives a surface which will wear from five to twenty years, depending
+upon the size and location of the cavity and tooth-structure. Buccal
+cavities in the first permanent molars, and lingual cavities in the
+superior incisors, filled for children from six to eight years of age,
+are still in good condition after a period of twenty years. Perhaps the
+limit is reached in the following cases, all in the mouths of
+_dentists_: One filling forty years old; one forty-two; four on the
+occlusal surface, fifty; in the latter case gold had been used in other
+cavities and had failed several times. Lingual cavities in molars and
+bicuspids can be perfectly preserved with tin. Tapes of No. 10 foil,
+from one to three thicknesses, can be welded together and will cohere as
+well or better than semi-cohesive gold foil, and it can be manipulated
+more rapidly; therefore, if desirable, any degree of contour can be
+produced, but the contour will not have the hardness or strength of
+gold, so in many cases it would not be practicable to make extensive
+contours with tin, owing to its physical characteristics.
+
+No. 10 will answer for all cases, and it is not as liable to be torn or
+cut by the plugger as a lower number, but one need not be restricted to
+it, as good fillings can be made with Nos. 4, 6, or 8. More teeth can be
+saved with tin than with any other metal or metals, and the average
+dentist will do better with tin than with gold. It is invaluable when
+the patient is limited for time or means, and also for filling the first
+permanent molars, where we so often find poor calcification of
+tooth-structure. In cases of orthodontia, where caries has attacked a
+large number of teeth, it is well to fill with tin, and await further
+developments as to irregularity and caries.
+
+If cavities are of a good general retaining form, that will be
+sufficient to hold the filling in place; but if not, then cut slight
+opposing angles, grooves, or pits. Cavities are generally prepared the
+same as for gold, except where there is a great deal of force brought
+upon the filling; then the grooves or pits may be a little larger;
+still, many cavities can be well filled with less excavating than
+required for gold, and proximal cavities in bicuspids and molars, where
+there is sufficient space, can be filled without removing the occlusal
+surface, and here especially should the cavities be cut square into the
+teeth, so as not to leave a feather edge of tin when the filling is
+finished, as that would invite further caries and prove an obstruction
+to cleansing the filling with floss.
+
+In proximal cavities involving the occlusal surface, cut the cervical
+portion down to a strong square base, with a slight pit, undercut, or
+angle, at the buccal and lingual corners; where there is sufficient
+material, a slight groove across the base, far enough from the margin so
+that it will not be broken out, can be made in place of the pit,
+undercut, or angle; then cut a groove in the buccal and lingual side
+(one or both, according to the amount of material there is to work
+upon), extending from the base to the occlusal surface; in most of these
+cases the occlusal grooves or pits would have to be excavated on account
+of caries; thus there would be additional opportunity for anchorage. In
+place of the grooves the cavity may be of the dovetail form. In nearly
+all proximal cavities in bicuspids and molars, some form of metal
+shield, or matrix, is of great advantage, as they prevent the tin from
+crushing or sliding out. By driving the tin firmly against the metal, a
+well-condensed surface is secured; and as the metal yields a little, we
+can with a bevel or thin plugger force the tin slightly between the
+metal and the margin of the cavity, thus making sure of a tight filling,
+with plenty of material to finish well. After removing the metal,
+condense with thin burnishers and complete the finish the same as for
+gold. Where no shield or matrix is used, or where it is used and removed
+before completing the filling, it is often desirable to trim the
+cervical border, for in either case there is more light and room to work
+when only a portion of the cavity has been filled. Tin cuts so much
+easier than gold, it is more readily trimmed down level with all
+cervical margins.
+
+Be sure that all margins are made perfect as the work progresses, and if
+the cavity is deep and a wide shield shuts out the light, then use a
+narrow one, which can be moved toward the occlusal surface from time to
+time.
+
+In filling the anterior teeth when the labial wall is gone, and the
+lingual wall intact or nearly so, use a piece of thin metal
+three-quarters of an inch long and wide enough to cover the cavity in
+the tooth to be filled, insert it between the teeth, and bend the
+lingual end over the cavity; the labial end is bent out of the way over
+the labial surface of the adjoining tooth, as shown in Fig. 4. When the
+labial wall is intact or nearly so, access to the cavity should be
+obtained from the lingual side, and in this case the bending of the
+shield would be reversed, as shown in Fig. 5. The shield is not
+absolutely essential, but it helps support the tin, and also keeps a
+separation.
+
+[Illustration: FIG. 4.]
+
+[Illustration: FIG. 5.]
+
+It is preferable to save the labial wall and line it with (say) five
+layers of No. 4 semi-cohesive gold folded into a mat and extended to the
+outer edge of the cavity; this gives the tooth a lighter shade, and
+bicuspids or molars can be filled in the same manner. Cases are on
+record where incisors with translucent labial walls, filled by this
+method, have lasted from twenty-three to thirty-seven years.
+
+
+
+
+CHAPTER VII.
+
+
+For the last ten years the writer has been using tin at the cervical
+margin of proximal cavities in bicuspids and molars, especially in deep
+cavities (now an accepted practice), and he finds that it prevents
+further caries oftener than any other metal or combination of metals he
+has ever seen used. In filling such cavities, adjust the rubber, and use
+a shield or matrix of such form as to just pass beyond the cervical
+margin; this will generally push the rubber out of the cavity, but if it
+does not, then form a wedge of wood and force between the metal and the
+adjoining tooth, thus bringing the metal against the cervical margin,
+and if a small film of rubber should still remain in the cavity, it may
+be forced out by using any flat burnisher which will reach it, or it can
+be dissolved out with a little chloroform. Fill from one-fourth to
+one-half of the cavity with tin, and complete the remainder with gold
+when the tooth is of good structure; this gives all the advantages of
+gold for an occlusal surface.
+
+Before beginning with the gold, have the tin solid and square across the
+cavity, and the rest of the cavity a good retaining form, the same as
+for gold filling; then begin with a strip of gold slightly annealed and
+mallet it into the tin, but do not place too great reliance upon the
+connection of the metals to keep the filling in place.
+
+On the same plan, proximal cavities in the anterior teeth can be filled,
+and also buccal cavities in molars, especially where they extend to the
+occlusal surface. The cervical margin should be well covered with tin
+thoroughly condensed, thus securing perfect adaptation, and a solid base
+for the gold with which the filling is to be completed. Time has fully
+demonstrated that the cervical margin is most liable to caries, and here
+the conservative and preservative qualities of tin make it specially
+applicable.
+
+"Electrolysis demonstrates to us that no single metal can be decomposed,
+but when gold and tin are used in the above manner they are united at
+the line of contact by electrolysis. The surface of both metals is
+exposed to the fluids of the mouth, and the oxid of tin is deposited on
+the tin, by reason of the current set up by the gold; thus some atoms of
+tin are dissolved and firmly attached to the gold, but the tin does not
+penetrate the gold to any great extent." (Dr. S. B. Palmer.)
+
+This connection of the metals assists in holding the filling in place,
+but it is more likely to break apart than if it was all gold. After
+electrolysis has taken place at the junction, it requires a cutting
+instrument to completely separate the tin and gold.
+
+For filling by hand pressure, use instruments with square ends and
+sides, medium serrations, and of any form or size which will best reach
+the cavity.
+
+For filling with the hand mallet, use instruments with medium
+serrations, and a steady medium blow with a four-ounce mallet; in force
+of blow we are guided by thickness of tin, size of plugger, and depth of
+serrations, strength of cavity-walls and margins, the same as in using
+gold. The majority of medium serrated hand mallet pluggers will work
+well on No. 10 tin of one, two, or three thicknesses. If the tin shows
+any tendency to slide, use a more deeply serrated plugger. The
+electro-magnetic, and mechanical (engine) mallet do not seem to work tin
+as well as the hand mallet or hand force, as the tendency of such
+numerous and rapid blows is to chop up the tin and prevent the making of
+a solid mass, and also injure the receiving surface of the filling. In
+using any kind of force, _always_ aim to carry the material to place
+before delivering the pressure, or blow.
+
+In order to obtain the best results, there must be absolute dryness, and
+care must be exercised, not thinking that because it is _tin_ it will be
+all right. Skill is required to make good tin fillings, as well as when
+making good gold fillings. Always use tapes narrower than the orifice of
+the cavity; they are preferable to rolls or ropes. After a few trials it
+is thought that every one will have the same opinion. A roll or rope
+necessarily contains a large number of spaces, wrinkles, or
+irregularities, which must be obliterated by using force in order to
+produce a solid filling; thus more force is employed, and more time
+occupied in condensing a rope, than a flat tape; the individual blow in
+one case may not be heavier than in the other, but the rope has to be
+struck more blows. The idea that a rope could be fed into a cavity with
+a plugger faster and easier than a tape has long ago been disproved.
+Many of the old-fashioned non-cohesive gold foil operators used flat
+tapes, as did also Dr. Varney, one of the kings of modern cohesive gold
+operators.
+
+The tape is made by folding any portion of a sheet of foil upon itself
+until a certain width and thickness is obtained. This tape is very
+desirable in small or proximal cavities where a roll or rope would catch
+on the margin and partially conceal the view.
+
+In the form of a tape, perhaps more foil can be put in a cavity, and
+there may be more uniform density than when ropes are used. Tapes can
+also be made by folding part of a sheet of foil over a thin, narrow
+strip of metal. Fold the tin into tapes of different lengths, widths,
+and thicknesses, according to the size of the cavity; then fold the end
+of the tape once or twice upon itself, place it at the base of any
+proximal cavity, and begin to condense with a foot plugger of suitable
+size, and if there is a pit, groove, or undercut which it does not
+reach, then use an additional plugger of some other form to carry the
+tin to place; fold the tape back and forth across the cavity, proceeding
+as for cohesive gold. In small proximal cavities a very narrow tape of
+No. 10, one thickness, can be used successfully. For cavities in the
+occlusal surface, use a tape as just described, generally beginning at
+the bottom or distal side, but the filling can be started at any
+convenient place, and with more ease than when using cohesive gold. In
+any case if the tin has a tendency to move when starting a filling,
+"Ambler's left-hand assistant" is used, by slipping the ring over the
+second finger of the left hand, letting the point rest on the tin. This
+instrument is especially valuable in starting cohesive gold (see Fig.
+6). This is the easiest, quickest, and best manner of making a good
+filling, relying upon the welding or cohesive properties of the tin.
+
+Many operators have not tried to unite the tin and make a solid mass;
+they seem to think that it cannot be accomplished, but with proper
+pluggers and manipulation it can be done successfully.
+
+[Illustration: FIG. 6.]
+
+For large occlusal or proximal cavities, the tapes may be folded into
+mats, or rolled into cylinders, and used on the plan of wedging or
+interdigitation, and good fillings can be produced by this method, but
+the advantage of cohesion is not obtained, and more force is required
+for condensing. They are, therefore, not so desirable as tapes,
+especially for frail teeth. When using mats or cylinders, the general
+form of the cavity must be depended upon to hold the filling in place.
+To make the most pliable cylinders, cut a strip of any desired width
+from a sheet of foil and roll it on a triangular broach, cutting it off
+at proper times, to make the cylinders of different sizes.
+
+A cylinder roller, designed by the author, is much superior to a broach.
+(See Fig. 7.) When the cavity is full, go over the tin with a mallet or
+hand burnisher, being careful not to injure the cavity-margin. Cut down
+occlusal fillings with burs or carborundum wheels, and proximal fillings
+with sharp instruments, emery strips or disks. After partially
+finishing, give the filling another condensing with the burnisher, then
+a final trimming and moderate burnishing; by this method a hard, smooth
+surface is obtained.
+
+Fillings on occlusal surfaces can be faced with No. 20 or 30 tin, and
+burnished or condensed, by using a burnisher in the engine, but do not
+rely upon the burnisher to make a good filling out of a poor one.
+
+[Illustration: FIG. 7.]
+
+By trimming fillings before they get wet, any defects can be remedied by
+cutting them out; then with a thin tape (one or two layers of No. 10)
+and serrated plugger proceed with hand or mallet force to repair the
+same as with cohesive gold.
+
+Another method of preparing tin for fillings is to make a flat, round
+sand mold; then melt chemically pure tin in a clean ladle and pour it
+into the mold; put this form on a lathe, and with a sharp chisel turn
+off thick or thin shavings, which will be found very tough and cohesive
+when freshly cut, but they do not retain their cohesive properties for
+any great length of time,--perhaps ten or twenty days, if kept in a
+tightly corked bottle. After more or less exposure to the air they
+become oxidized and do not work well, but when they are very thin they
+are soft, pliable, and cohesive as gold, and any size or form of filling
+can be made with them.
+
+Among the uses of tin in the teeth, the writer notes the following from
+Dr. Herbst, of Germany: "After amputating the coronal portion of the
+pulp, burnish a mat of tin foil into the pulp-cavity, thus creating an
+absolutely air-tight covering to the root-canal containing the remainder
+of the pulp; this is the best material for the purpose." There has been
+a great deal said about this method, pro and con, notably the latter.
+The writer has had no practical experience with it, and it need not be
+understood that he indorses it.
+
+If a pulp ever does die under tin, perhaps it will not decompose as
+rapidly as it otherwise would, owing to its being charged with
+tin-salts.
+
+The Herbst method of filling consists in introducing and condensing tin
+in cavities by means of smooth, highly tempered steel engine or hand
+burnishers. In the engine set of instruments there is one oval end
+inverted cone-shaped, one pear-shaped, and one bud-shaped. The revolving
+burnisher is held firmly against the tin, a few seconds in a place, and
+moved around, especially along the margins, not running the engine too
+fast. Complicated cavities are converted into simple ones by using a
+matrix, and proximal cavities in bicuspids and molars are entered from
+the occlusal surface. The tin foil is cut into strips, and then made
+into ropes, which are cut into pieces of different lengths; the first
+piece must be large enough so that when it is condensed it will lie
+firmly in the cavity without being held; thus a piece at a time is added
+until the cavity is full. The hand set of burnishers has four which are
+pear-shaped and vary in size, and one which is rather small and
+roof-shaped. In filling and condensing they are rotated in the hand
+one-half or three-quarters of a turn.
+
+Dr. Herbst claims a better adaptation to the walls of the cavity than by
+any other method. Proximal cavities in bicuspids and molars can easily
+be filled; the tin can be perfectly adapted against thin walls of enamel
+without fracturing them; less annoyance to the patient and less work for
+the dentist; can be done in half the time required for other methods.
+
+Fees should be reasonably large, certainly more than for amalgam, for
+we can save many teeth for a longer time than they could have been
+preserved with cohesive gold. Many are not able to pay for gold, but
+they want their teeth filled and _saved_, and it is expected that we
+will do it properly and with the right kind of material; thus it is our
+duty in such cases to use more tin and less amalgam.
+
+We should always take into consideration the amount of good accomplished
+for the patient,--the salvation of the tooth,--and if we are sure, from
+experience and observation, that the tin filling will last as long as a
+gold one in the same cavity, or longer, then the fee should be as much
+as for gold, with the cost of the gold deducted. The amount of the fee
+ought to be based upon the degree of intelligence, learning, and skill
+required; upon the amount of nervous energy expended; upon the draft
+made on the dentist's vitality; upon what benefit has been given the
+patient; upon the perfection of the result; and, everything else being
+equal, upon the time occupied; the value of this last factor being
+estimated in proportion to the shortness of it.
+
+
+
+
+CHAPTER VIII.
+
+
+Dr. Robinson's Fibrous and Textile Metallic Filling is a shredded
+metallic alloy, mostly tin, and has the appearance of woven or felt
+foil. It is prepared in a machine invented by the doctor especially for
+the purpose, and he gives directions for using as follows: "Cut the
+material into strips running with the selvage, and fill as you would
+with soft foil; use it in all surrounding walls, and finish with a
+mallet burnisher. Where the surface comes to hard wear, weld on gold
+with long, sharp serrated pluggers, and finish the same as with gold
+fillings. The advantage over gold for cervical, buccal, and lingual
+walls is the perfect ease with which it is adapted, and it can be
+burnished so as to be absolutely impervious to moisture. Sharp,
+coarse-serrated pluggers are particularly desirable when using hand
+pressure." It comes in one-half-ounce boxes, filled with sheets less
+than two inches square; the thin ones are used for filling, and the
+thick ones make good linings for vulcanite.
+
+This material is easy to manipulate, but great care is required in
+condensing at cavity-margins, so as to make a tight filling, and also
+not injure the margins. It makes as hard a surface as tin foil, and can
+be cut, polished, and burnished so that it is smooth and looks well; it
+can be used in temporary or chalky teeth, as a small amount of force
+condenses it. By using a matrix proximal cavities can be filled from
+one-fourth to one-half full, and the rest filled with gold, relying on
+the form of the cavity to hold the gold, regardless of its connection
+with the fibrous material. If the surface is not overmalleted so as to
+make it brittle or powdery, a strip of No. 4 cohesive gold, of four or
+five thicknesses, may be driven into it with a hand mallet and plugger
+of medium serrations; this union is largely mechanical, but of
+sufficient tenacity to make manipulation easy, as the material makes a
+solid foundation to build upon. After exposure to the oral fluids,
+electrolysis takes place at the junction of the metals.
+
+In 1884 Dr. Brophy said, "I have used Robinson's material for two years,
+and find it possesses good qualities, and can be used in deciduous
+teeth, first permanent molars, and cervical margins with better results
+than can be obtained with any other material by the majority of
+operators."
+
+Malleted with deeply serrated pluggers, it will make a filling which
+will not leak. It has saved many teeth from caries at the cervical
+margin where it might have recurred sooner had cohesive gold been used.
+In the mouth it changes color about the same as tin foil, and a few
+fillings did not maintain their integrity, but became crumbly and
+granular.
+
+For conducting properties it ranks about with tin, and fillings can be
+made more rapidly than with cohesive gold. We have used ounces of it,
+but time has proved that everything that can be done with it in filling
+teeth can also be accomplished as well and in some cases better with tin
+foil.
+
+In 1878 Dr. N. B. Slayton patented his Felt Foil, which was said to be
+tin cut into hair-like fibers by a machine, then pressed into small
+sheets and sold in one-half-ounce books, but it sold only to a very
+limited extent. Soon after this Dr. Jere Robinson, Sr., invented a
+machine and began the manufacture of a similar article, but he found he
+was infringing on the Slayton patent, so he purchased the Slayton
+machine and made satisfactory terms to continue his own manufacture of
+fibrous material. After this little was heard of Slayton's Felt Foil,
+but Robinson's was considerably used. The two materials look and are
+manipulated almost exactly alike. Dr. Robinson has both of
+above-mentioned machines now in his possession.
+
+Archibald McBride, of Pittsburg, Pa., in 1838, made a roll of a portion
+of a sheet of tin, and then used just enough gold to cover it, aiming
+to keep the gold on the surface, so as to have the filling look like one
+of all gold, and not with the idea of deriving any special benefit from
+the effects of wear or preservation as obtained by thus combining the
+two metals. The fee for a gold filling was one dollar; tin, fifty cents.
+Some operators have advocated using tin and gold (symbol Tg), rolled or
+folded together in alternate layers, thus exposing both metals to the
+fluids of the mouth; claiming that fillings can be made quicker, are not
+so subject to thermal changes, and can be inserted nearer the pulp than
+when gold is used. This may be true in comparison with gold, but these
+three claims are entirely met by using tin alone. Others say that this
+union of gold and tin will preserve the teeth as well as a correct gold
+filling, making no conditions or restrictions as to tooth-structure or
+location of cavity. They say that it preserves the cervical margin
+better than gold; that it expands _slightly_.
+
+A description of some different methods of combining and manipulating
+tin and gold is subjoined:
+
+(_a_) Two sheets of No. 4 cohesive gold and one of the same number of
+tin are used; place the tin between the gold, cut off strips, and use
+with hand or mallet force the same as cohesive gold; if non-cohesive
+gold is used, the strips can be folded into mats or rolled into
+cylinders, and are used on the wedging plan, the same as non-cohesive
+gold, or the strips can be folded back and forth in the cavity until it
+is full.
+
+(_b_) Lay a sheet of non-cohesive gold, No. 3, on a sheet of tin of the
+same number, cut off strips, roll into ropes and use as non-cohesive
+gold. It is easily packed and harder than tin, and has a preservative
+action on the teeth. Line the cavity with chloro-balsam as an insulator
+against possible currents and moisture; especially should this be done
+in large cavities or chalky teeth.
+
+(_c_) A sheet of non-cohesive gold, No. 4, is laid on a sheet of tin of
+the same number, cut into strips and rolled into cylinders, or folded
+into blocks, always in equal portions; then they will unite to the
+extent of two leaves. These fillings sometimes become a solid mass about
+the color of amalgam, and last very well, as the metals have become
+united by electrolysis. An excess of tin will be marked by lines or pits
+in the filling, showing where the tin has been disintegrated or
+dissolved by the chemical action which occurs on the surface exposed to
+moisture.
+
+No doubt, good fillings have been made by the above methods, yet some
+were granular, gritty, and were easily removed, while others were quite
+smooth and hard; probably in the first instance the proportion of tin
+and gold was not proper,--that is, not equal; or it was not well
+condensed. Tin being the positive element, it is more easily acted on
+and disintegrated by electrolysis (chemical action of the fluids).
+
+When this combination does become hard, it wears longer than tin on an
+occlusal surface, but we believe that in some cases where it was used
+the teeth could have been saved just as well with either tin or gold, or
+by filling part of the cavity with tin and the rest with gold.
+
+If tin foil is laid on 22-carat gold and vulcanized, it becomes
+thoroughly attached and will take a tin polish; the attraction or
+interchange of atoms takes place to this extent.
+
+This combination of tin and gold can be used at the cervical margin, or
+a cavity can be lined with it, and the remainder filled with cohesive or
+non-cohesive gold.
+
+"Tin and gold (Tg) folded or rolled together in equal portions possesses
+a greater number of desirable properties than any other material, for it
+is easily adapted, has antiseptic action and a lower conductivity than
+gold. A new filling is harder than tin, softer than gold, but after a
+time it becomes as hard as amalgam. It oxidizes and thus helps make
+tight margins, and is very useful at cervical margins; generally
+discolors, but not always, and does not discolor the tooth unless a
+carious portion has been left, and then only discolors that portion. In
+oral fluids it is indestructible if well condensed, otherwise it is
+crumbly. There is no change of form, except a _slight_ expansion, which
+does no harm. A weak electric current is set up between the gold and
+tin, and tin oxid is formed. The hardening and discoloration both depend
+upon the separation of the tin by the electrical action and its
+deposition on the surface of the gold. I generally prepare cavities the
+same as for non-cohesive gold, but a Tg filling may be held in a more
+shallow cavity and with less undercuts than for gold. Hand pressure is
+adopted, but a mallet may be used advantageously. Lay a sheet of No. 4
+non-cohesive gold on a sheet of No. 4 tin, then cut into strips and
+twist into ropes; keep the tin on the outside, for it does not tear as
+easily as gold. Carry the material against the walls and not against the
+base, otherwise the filling will be flat or concave; but should this
+occur, then force a wedge-shaped plugger into the center of the filling,
+and drive the material toward the walls, and then fill the hole or
+remove all the filling and begin anew.
+
+"In very deep cavities use a mat of Tg, dampened in carbolic acid and
+dipped in powdered thymol, as a base; this has an antiseptic action, and
+also prevents pressure on or penetration into the pulp.
+
+"Drs. Abbot, Berlin; Jenkins, Dresden; Sachs, Breslau, have observed
+tin-gold fillings from fifteen to twenty-five years, and say that for
+certain cases it is better than any other material. I use square-pointed
+pluggers (four-cornered), as part of the packing is done with the side
+of the plugger. Tg is useful in partly erupted molars, buccal cavities
+under the gums, occlusal cavities in temporary teeth, cavities where all
+decay cannot be removed. Use Tg with a gold capping in small, deep
+occlusal cavities, cavities with overhanging walls, occlusal cavities
+with numerous fissures, large, deep occlusal cavities near the pulp, in
+proximal cavities.
+
+"Line labial walls of incisors with non-cohesive gold, and fill the
+remainder with Tg. For repairing gold fillings I use Tg." (Dr. Miller,
+Berlin, _Dental Cosmos_, 1890.)
+
+Dr. Jenkins, of Dresden, says, "I use Tg in soft, imperfect teeth, of
+which there are plenty in Germany, because it has pliability,
+adaptability, slight susceptibility to thermal changes, makes a
+water-tight joint, very useful at cervical margins, and can be used with
+a minimum amount of pressure. When packed dry and with the gold next to
+the tooth, discoloration occurs only on the surface; packed wet, the
+whole discolors. I do not attribute its success to electrical action.
+Lay a sheet of No. 4 tin on a sheet of No. 4 non-cohesive gold, fold so
+as to keep the gold on the outside; use the strip with lateral pressure,
+doubling it upon itself."
+
+Dr. A. H. Thompson: "After several years' successful use of tin-gold, I
+commend it for approximal cavities, cervical margins, and frail walls.
+The oxid formed penetrates the enamel and dentin; if a filling wears
+down, cover the surface with gold."
+
+Dr. Pearson: "I do not like tin and gold in alternate layers. I prefer
+No. 10 tin foil."
+
+Dr. James Truman: "I believe that tin-gold has a positive value as a
+filling-material."
+
+"I prepare tin-gold by taking a sheet of No. 4 non- or semi-cohesive
+gold, fold them together (or twist them) so as to have the gold on the
+outside, and then fill any cavity with it. Since adopting the above
+combination I have almost abandoned amalgam. This is recommended on
+account of its density, ease of insertion, capacity for fine finish,
+non-conducting and non-shrinking qualities, and compatibility with
+tooth-substance. Those who have not used it will be surprised at the
+rapidity with which it can be manipulated. It may be employed in any
+cavity not exposed to view, also in crown, buccal, and approximal
+fillings which extend into the occlusal surface, as it offers an
+astonishing resistance to wear. It can be used anywhere that amalgam
+can, and with more certainty of non-leakage, and it has the additional
+advantage that it can be finished at the same sitting. Care is necessary
+in manipulating it, so as to avoid chopping. I use hand pressure when
+filling, and the mallet to condense the surface." (Dr. A. W. Harlan,
+_Independent Practitioner_, 1884.)
+
+"Pure tin foil is employed in connection with non-cohesive gold in
+filling proximal cavities in bicuspids and molars; a sheet of gold and a
+sheet of tin are folded together." (C. J. Essig: "Prosthetic
+Dentistry.")
+
+Dr. Benj. Lord says, "A combination in which I find great interest is in
+the use of soft or non-cohesive gold with tin foil. This is no novelty
+in practice, but I think that, for the most part, too great a proportion
+of tin has been used, and hence has arisen the objection that the tin
+dissolved in some mouths. I am satisfied that I myself until recently
+employed more tin than was well. I now use from one-tenth to one-twelfth
+as much tin as gold, and no disintegration or dissolving away of the
+tin ever occurs. I fold the two metals together in the usual way of
+folding gold to form strips, the tin being placed inside the gold. The
+addition of the tin makes the gold tougher, so that it works more like
+tin foil. The packing can be done with more ease and certainty; the
+filling, with the same effort, will be harder, and the edges or margins
+are stronger and more perfect.
+
+"The two metals should be thoroughly incorporated by manipulation. Then,
+after a time, there will be more or less of an amalgamation. By using
+about a sixteenth of tin, the color of the gold is so neutralized that
+the filling is far less conspicuous than when it is all gold, and I very
+often use such a proportion of tin in cavities on the labial surfaces of
+the front teeth.
+
+"If too much tin is employed in such cases, there will be some
+discoloration of the surface of the fillings; but in the proportion that
+I have named no discoloration occurs, and the surface of the filling
+will be an improvement on gold in color."
+
+"Dr. Howe. I would like to ask Dr. Lord whether, in referring to the
+proportions of tin and gold, he means them to be considered by weight?
+
+"Dr. Lord. No, not by weight, but by the width of the strip of tin and
+the width of the strip of gold. I get the proportions in that way, then
+lay the tin on the gold and fold the gold over and over, which keeps the
+tin inside the gold.
+
+"Dr. Howe. Will Dr. Lord tell us whether he refers to the same numbers
+of gold foil and tin foil; as, for instance, No. 4 gold and No. 4 tin?
+
+"Dr. Lord. I use the No. 5 gold, and tin, I think, of about the
+same number, but I always use No. 5 gold, both cohesive and
+non-cohesive."--_New York Odontological Society Proceedings_, 1893, page
+103.
+
+"Tin and gold, in the proportions generally used, do not present a
+pleasing color; when finished, it looks but little better than tin, and
+after a short time it grows dark, and sometimes black. I use five parts
+of gold to one of tin, prepared as follows: Lay down one sheet of
+Abbey's non-cohesive gold foil, No. 6; upon this place a sheet of No. 4;
+upon this place a sheet of White's globe tin foil, No. 4; upon this
+another sheet of Abbey's non-cohesive gold, No. 4; upon this a sheet of
+No. 6. Cut into five strips and crimp; the crimped strips are cut into
+pieces a little longer than the depth of the cavity to be filled; some
+of the strips are rolled into cylinders, others are left open, because
+easier to use in starting a filling. The color of this combination is
+slightly less yellow than pure gold, and hardens just as rapidly as when
+the proportions are one to one, but does not become quite as hard. This
+preparation is non-cohesive, and should be inserted by the wedge
+process. I use it in the grinding surface of molars and bicuspids,
+buccal cavities in molars and bicuspids, cervical fissure pits in
+superior incisors, proximal cavities in bicuspids and molars. If
+proximal cavities are opened from the occlusal surface, the last portion
+of the filling should be of cohesive gold to withstand mastication. In
+simple cavities I place as many pieces as can be easily introduced,
+using my pliers as the wedging instrument to make room for the last
+pieces, and then condense the whole. If the cavity is too deep for this,
+I use Fletcher's artificial dentin as a base, because it partly fills
+the cavity and the ends of the cylinders stick to it. After an
+approximal cavity is prepared, use a matrix held in place by wooden
+wedges; the cylinders are about one-eighth of an inch long, and
+condensed in two or three layers so as to secure perfect adaptation;
+hand pressure is principally used, but a few firm strokes with a hand
+mallet are useful. When ready to add the cohesive gold for the
+grinding-surface, a few pieces of White's crystal mat gold should first
+be used, because it adheres beautifully; thus a perfect union is
+secured, but I never risk adding the gold without leaving a little
+undercut for it in the tooth. By this method we obtain a beautiful
+contour filling in a short time. Fillings should be burnished and then
+polished with a fine strip, or moistened pumice on a linen tape. Where
+cohesive gold is used for the entire filling, in many cases the
+enamel-walls, already thin near the cervical margin, are made thinner by
+the unavoidable friction of the polishing strips, but tin and gold is so
+soft that a good surface is obtained in a few moments, and this danger
+is reduced to a minimum. The surface is as smooth as a cohesive gold
+filling, while such a surface is impossible with non-cohesive gold. In
+cavities which extend so far beyond the margin of the gum that it is
+impossible to adjust the rubber-dam, I prepare the cavity as usual, then
+adjust a matrix, disinfect, dry, and fill one-third full with tin and
+gold, then remove the matrix, apply the rubber, place matrix again in
+position, and complete the filling by adding a little tin and gold, then
+pure gold." (Dr. W. A. Spring, _Dental Review_, February, 1896.)
+
+Dr. T. D. Shumway says, "To have a scientific method of treatment, there
+certainly must be a recognition of what is known of the nature of
+tooth-structure. The method adopted more than a quarter of a century
+ago, and which is at present employed, does not accord with the
+teachings of the physiologist and microscopist; it is in direct
+opposition to natural law. Each new discovery in the minute structure of
+the teeth makes this more plain; pounding the teeth with a mallet cannot
+be defended on scientific grounds. That it has not resulted more
+disastrously is due to the wonderful recuperative energy of nature to
+repair injury. No one would think of attempting to arrest and prevent
+disintegration in any other vital organ by abrasion. Why, then, in
+operation on the teeth, should we reverse the plain, simple teaching of
+nature? Placing cohesive gold against the dentinal walls by pounding it
+to heal a lesion is opposed to natural law. Cohesive gold will not be
+mastered by force; if compelled to yield by superior strength, it seeks
+a way to release itself; it is easily coaxed, but not easily driven.
+Cohesive gold will unite with tin at an insensible distance just as
+cohesive gold unites with itself; this union takes place without force
+or pressure. Exactly what takes place when gold and tin are brought in
+contact in the way described we do not know; we can only say that there
+appears to be a perfect union. When cohesive gold was introduced to the
+profession, while it was softer than non-cohesive foil, it was found to
+resist under manipulation. This resistance is in accordance with the
+well-known law that all crystalline bodies, when unobstructed, assume a
+definite form. With gold the tendency is to a spherical form. The
+process of crystallization is always from within outward. The mallet was
+introduced to overcome the resistance caused by the development of the
+cohesive property. Pounding gold with a mallet only increases its
+crystallization. A crystalline body coming in contact with a fibrous one
+can neither be antiseptic nor preservative; a filling-material which
+possesses these properties must be one that corresponds or is in harmony
+with tooth-substance.
+
+"In the interglobular spaces there is a substance which is called
+amorphous or structureless, and a filling to be in harmony with this
+substance should be amorphous or structureless in its composition. The
+only materials we have which meet these conditions are gutta-percha and
+tin. It is its structureless character that gives to tin its value.
+Coming in contact with the living dentin, it is easily adapted, and does
+not excite inflammation; it does not interfere with the process going on
+within the teeth to heal the lesion caused by caries. A wound from a
+bullet made of tin, unless it struck a vital part, nature would heal,
+even if the cause of the wound was not removed, by encysting the ball.
+This process of nature of repairing injury by encysting the cause is of
+interest to the dentist in the study of suitable filling-materials. Tin
+is very useful at the cervical margin of cavities; it acts as an
+antiseptic or preservative, and reduces the liability to subsequent
+decay. It is our endeavor to obtain a filling that will preserve the
+teeth and reduce the liability to, if not wholly prevent, secondary
+decay. The law of correspondence is of more consequence than the
+mechanical construction of the filling. Tin can be used without that
+rigid adherence to mechanical rule that is necessary to retain a filling
+of cohesive gold; thus less of the tooth needs to be sacrificed.
+
+"Gold will unite with tin under certain conditions so as to form
+apparently a solid mass. By a combination of these metals, not by
+interlacing or incorporating one in the other, but by affinity, secured
+by simple contact, we have all the preservative qualities of tin
+combined with the indestructible properties of gold. For the base of the
+filling we have a material in harmony with tooth-substance, introduced
+in a way that is in accord with the law that governs all living bodies,
+and for the outside a crystalline substance that corresponds to the
+covering of the teeth. This covering of gold is a perfect shield to the
+base, and the field for the display of artistic skill in restoring
+contours is as broad as though gold was used entirely. Will a filling of
+this kind withstand mastication? There is in the economy of nature a
+provision made to overcome the resistance of occlusion. The teeth are
+cushioned in the jaw and yield under pressure. The elasticity of the
+substance of which the teeth are made is well understood. Ivory is the
+most elastic substance known. The teeth coming together is like the
+percussion of two billiard balls. Now a filling to save the teeth should
+correspond as nearly as possible with the tooth-substance; it should not
+be arbitrary, but elastic and yielding. Tin is interdigitous; it expands
+laterally, and is almost as easily introduced as amalgam, and when put
+in place does not have to be bound to be retained. Tin, with an outside
+covering of gold to protect it, makes a filling to which amalgam bears
+no comparison. In the light of scientific investigation there can be but
+one method--a method based upon the recognized principle that the
+_filling-material_ and the _manner_ of _introducing_ it shall correspond
+to and be in harmony with the living, vital organism with which it comes
+in contact.
+
+"After excavating, the cavity is treated with absolute alcohol, as
+cleanliness and thorough dryness are absolutely essential.
+
+"The _tin_ is put in with steel pluggers, after the method of wedging;
+it must be thoroughly condensed, so as to leave a smooth surface, and
+enough used to come up to where the enamel and dentin join.
+
+"The effect is not produced by incorporating or interlacing the gold
+with the tin; we rely upon the affinity of the two metals to retain the
+gold; no undercuts, angles, or pits are made in the tin, dentin, or
+enamel. The gold, extra cohesive from No. 4 to 40, is made to adhere to
+the tin by simple contact, without pressure or force; the union is not
+mechanical.
+
+"The instruments used for filling the remainder of the cavity with gold
+are Shumway's ivory points, which adapt the gold nicely to the margin.
+
+"The set consists of five and were patented in 1881, and have been used
+by me since that time for manipulating cohesive gold. One 'point' is for
+proximal cavities in the anterior teeth; three 'points' of different
+sizes are for occlusal cavities; one 'point' for proximal cavities in
+bicuspids and molars and labial and buccal cavities; the sides, edges,
+and ends of the 'points' are used, as the purpose is simply to obtain
+contact.
+
+"The 'point' shown full size in Fig. 8 is of more general application
+than any of the others, and is used for proximal cavities in bicuspids,
+also labial and buccal cavities. The handle is made of ebony, and has a
+silver ferrule, from which the ivory extends to the end and completes
+the instrument.
+
+"The metal pin in the end of the handle is for picking up and carrying
+the gold."
+
+[Illustration: FIG. 8.]
+
+Tin has been used successfully for completely lining cavities, filling
+the remainder with gold; it is also useful for repairing gold fillings.
+
+Two or three thicknesses of tin foil may be pressed into a cavity with a
+rubber point or hard piece of spunk, allowing it to come well out to the
+margin; filling the rest with amalgam.
+
+"As a lining it presents to dentin an amalgam of tin and mercury which
+does not discolor the dentin like ordinary amalgam, and helps do away
+with local currents on the filling, which is one cause of amalgam
+shrinkage in the mouth." (Dr. S. B. Palmer.)
+
+When caries extends to the bifurcation of roots, make a mat of two or
+three layers of tin, place it in the bifurcation and use it as a base in
+filling the rest of the cavity with amalgam.
+
+Tin is second in importance in alloys for amalgam, as it increases
+plasticity, prevents discoloration, reduces conductivity and edge
+strength, retards setting, favors spheroiding, therefore should not be
+the controlling metal.
+
+It will be noticed that when cavities are lined with tin foil, it only
+constitutes a small part of the filling, and that it has not been melted
+with the other metals in the alloy before being amalgamated.
+
+A thick mat of tin has been recommended as a partial non-conductor under
+amalgam fillings.
+
+Plastic tin can be made by pouring mercury into melted tin, or by mixing
+the fillings with mercury at ordinary temperatures; it has a whitish
+color, and if there is not too much mercury it occurs in the form of a
+brittle granular mass of cubical crystals. Generally amalgams of tin and
+mercury do not harden sufficiently, but forty-eight parts of mercury and
+one hundred of tin make a fairly good filling, said to have a
+therapeutical value; it should not be washed or squeezed before using,
+and "is not a chemical combination."
+
+"Tin unites with mercury in atomic proportions, forming a weak
+crystalline compound." (Dr. E. C. Kirk.)
+
+Mercury and tin readily unite as an amalgam under ordinary
+circumstances, and form a definite chemical compound having the formula
+Sn_{2}Hg. (Hodgen.)
+
+Another preparation of tin is known as stannous gold; it is manufactured
+in heavy sheets and used the same as cohesive gold foil, and can be
+easily manipulated, for it is rather plastic.
+
+Crystal tin for taking the place of tin foil:
+
+"Take chemically pure hydrochloric acid and dissolve tin foil in it
+until a saturated solution is obtained; this may be done speedily by
+heating the acid to a boiling point, or the same thing can be
+accomplished in a few hours with the acid cold; it is then chlorid of
+tin. It is then poured into a clean vessel and an equal quantity of
+distilled water added; then a clean strip of zinc is plunged into the
+solution, and tin crystals are deposited on the zinc; when there is
+sufficient thickness on the zinc, remove both, and slip the crystals off
+from the zinc into pure water, clean the zinc thoroughly, and reinsert
+for another coating. The character of the crystallization will be
+modified by the extent of the dilution of the solution in the first
+place. Wash the tin in pure water until all traces of the acid are
+removed, or a few drops of ammonia can be added to neutralize the acid.
+It was suggested that it would be desirable to have some acid remain in
+the tin for filling teeth in which there is no sensitive dentin. We have
+put in a few fillings, and it works beautifully, and makes firmer
+fillings than foil. It must be kept in water (probably alcohol is
+better). It is pure tin, unites perfectly, and works easier than foil."
+(Dr. Taft, _Dental Register of the West_, 1859.)
+
+For some years it was considered the best practice to enlarge all
+root-canals and fill them with gold; in many of these cases the crown
+cavities were filled with tin.
+
+Tin has been used for filling root-canals, but should there happen to be
+any leakage through the foramen or tooth-structure, the tin will
+discolor, and there may be infiltration into the crown, thus causing
+discoloration, which might be objectionable if the crown was filled with
+gold. Chloro-percha, gutta-percha, and oxychlorid of zinc are much
+better for this purpose.
+
+The apical quarter of a canal has been filled with tin, and the
+remainder with cement. Tin can be used for filling root-canals. Roll on
+a broach small triangular pieces of the foil into very small cone-shaped
+cylinders, carry to place, then withdraw the broach, and force in the
+cylinder with the same or a larger broach; sometimes it is necessary to
+use another broach, to push the cylinder off from the one on which it is
+rolled. Another method is to carry and pack into the canal by means of a
+broach, very narrow strips of No. 10 or 20 foil; or the apical third of
+the canal could be filled with gold and the rest with tin.
+
+"About four years ago I concluded to try tin for filling root-canals;
+then I began to look for patients whose general health was good, who had
+strong, hardy-looking teeth, and kept their mouths in good condition. I
+found one who answered all my requirements, with a molar to be filled,
+and they would not have it filled with gold, or could not, on account of
+the expense. I filled the canals with tin and the crown with amalgam.
+After filling thirty-eight molars in this way I stopped for
+developments. In six or seven weeks a lady returned with an inferior
+molar abscessed, but at the time it was filled the circumstances were
+such that it could not be properly treated. In nine months a gentleman
+for whom I had filled four molars returned with an inferior one
+abscessed. This is the sum-total of abscessed teeth where tin was used
+in the root-canals, at the end of four years. The others are in good
+condition, as I have seen them every six months. The roots were treated
+from four to six weeks with carbolic acid before filling." (Dr. A. W.
+Harlan, _Missouri Dental Journal_, 1872.)
+
+"Tin foil is just as good as gold for filling root-canals, as it is
+entirely innocuous and sufficiently indestructible, while its softness
+and pliability commend it. Where gold is to be used for the crown, it is
+better to fill the bulbous portion of the pulp-cavity with gold also, so
+as to weld these portions of gold together. The success of Dr. Harlan's
+treatment was about equal to what might be expected from the same number
+of teeth where the canals had been filled with gold." (Editor, _Missouri
+Journal_.)
+
+Shavings turned from a disk of pure tin have been used in combination
+with Watts's sponge gold for filling teeth, either by making a portion
+of the filling from each metal or using them indiscriminately.
+
+A mat of tin foil dipped in chloro-percha can be used to cap an exposed
+pulp, or a concave tin disk can be used for the same purpose. A mat of
+tin has been used over a slight exposure of the pulp, because of its
+slight conduction of heat and cold, thus avoiding much thermal
+irritation and stimulating recuperation.
+
+Some use Robinson's fibrous material as a surface for tin fillings,
+thinking that it is harder and will wear longer because of the erroneous
+notion that it has platinum in it.
+
+
+
+
+CHAPTER IX.
+
+
+Tin has been recommended for temporary fillings in sensitive cavities,
+because it is soft and easily packed in contact with the walls, has
+therapeutic value, and after a time, when the temporary filling is
+removed, the cavity is not as sensitive as formerly.
+
+It has been observed that starting gold in a sensitive cavity causes
+pain, but starting tin in the same place seldom does.
+
+As long as tin preserves its integrity it preserves the tooth, therefore
+tin fillings should not be repaired with amalgam, as their integrity may
+be destroyed. Cavities can be partly filled with tin and completed with
+sponge, fibrous, or crystalloid gold, after the manner described for
+beginning with tin and finishing with gold foil.
+
+"I advocated tin at the cervical wall, cervico-lingual and
+cervico-buccal angles to the thickness of 24 plate. Then complete the
+filling with gold. Some of my most successful efforts in saving soft
+teeth have been made in this way. This method has great value over gold
+for the whole filling, but there are two objections to it: First, it
+imparts to the cervical border the color and appearance of decay, so
+that in three cases where an instrument passed readily into the tin I
+have removed the fillings, without any necessity for it, not even
+finding any softening of the margins. Second, its use requires the same
+conditions of dryness, shape of cavity, delicate manipulation,
+inconvenience to patient, and strain upon the operator as when gold is
+used alone." (Dr. D. D. Smith, _Dental Cosmos_, 1883.) He admits that
+this method saves _soft_ teeth and also cervical margins. Do not those
+two very important factors more than counterbalance the color, and
+oversight of the dentist?
+
+Dryness is an essential in making the best filling with any material,
+and the time and strain consumed by the majority of operators in filling
+with tin is not more than one-half what it is in using gold.
+
+"I use tin at the cervical margin of all proximal cavities in bicuspids
+and molars. I prepare a matrix of orange-wood to suit each case, letting
+it cover about one-third of the cavity, then fill with tin condensed by
+hand force and automatic mallet; now split the matrix and carefully
+remove it piece by piece, so as not to disturb the tin; then trim and
+finish this part of the filling. Make another wooden matrix, which
+covers the tin and remainder of the cavity, and fit it snugly to place.
+Use a coarsely serrated plugger and begin packing non-cohesive gold
+into the tin, letting it fill about one-third more of the cavity; then
+complete the last third (surface) with cohesive gold. I have tested this
+method for twenty years, and it has given me splendid results. I always
+tell patients that there will appear sooner or later a slight
+discoloration near the gum, which must not be mistaken for caries." (Dr.
+A. P. Burkhart.)
+
+Another use for tin in the operating-room is found in Screven's
+"Gutta-percha-coated Tin Foil," a cohesive, antiseptic non-conductor, of
+which the inventor says: "Cement fillings that have been kept dry for
+ten hours after mixing will be much harder than those soon exposed to
+moisture, and they will retain that hardness though exposed to moisture
+afterward. This preparation will keep a filling perfectly dry in the
+mouth, and when removed the filling will be found hard as stone. There
+is nothing better for lining cavities, holding nerve-caps in position,
+holding a preparation in place when devitalizing a pulp where the tooth
+is so much broken away as to make it difficult to prevent a filling
+showing through the enamel, and for many other purposes."
+
+High-heat gutta-percha has been used as a base in deep occlusal, buccal,
+and approximal cavities, completing the fillings with tin. Occlusal
+cavities may be filled with tin; then after the filling is condensed and
+finished, drill out the center and fill with cohesive gold, not cutting
+away the tin so as to expose the margin; such fillings wear well, as
+much of the attritial force comes on the gold portion of the filling.
+
+With the exception of the part in brackets, the following article is
+from the _British Journal_, May, 1887:
+
+"If a person eats an oyster stew at 130 deg. F., a gold filling would carry
+the difference between the temperature of the stew and that of the
+mouth, 130 - 98 = 32 deg., almost undiminished to the bottom of the cavity;
+allowing 2 deg. of diminution, then the cavity around the gold filling has
+assumed 128 deg.; now the person feels warm and drinks ice-water at 32 deg..
+Taking into consideration the specific heat of the gold filling, it will
+assume about 40 deg., which it carries with a diminution of the cold of
+about 4 deg.,--that is, as if it was 44 deg.,--into the interior of the cavity;
+then the cavity will assume 44 deg., the difference within one-tenth of a
+minute being 128 - 44 = 84 deg., a change which would produce a violent
+inflammation in any organ which was not accustomed to it. This
+derangement in the tooth means interruption of circulation, and young
+teeth will be most affected.
+
+"Thermal effect depends on heat-conducting power [gold is nearly four
+times as good a conductor of heat as tin] and also on specific heat, so
+the more the latter approaches that of the tooth the less it is liable
+to produce sudden changes [thus favoring tin]. Specific heat manifests
+itself by the speed of changes, while the heat-conducting power
+influences the intensity [then the intensity of heat in a gold filling
+would be three or four times as much as in a tin filling]. In speed gold
+produces this change in one-tenth of a minute" [tin in one-fifth,--that
+is, gold absorbs heat and expands about twice as fast as tin].
+
+In 1838 Dr. J. D. White introduced sharp-wedge-shaped instruments for
+filling teeth, and he claims to have been the first to use them; they
+pack laterally as well as downward, and present as small a surface to
+the filling as possible, so that the greatest effect may be produced
+upon a given surface with a given power. Rolls of either tin or gold are
+made by cutting any desirable portion from a sheet of No. 4 foil; cut
+this portion once transversely, place on a napkin or piece of chamois,
+then with a spatula fold a very narrow portion of the edge once upon
+itself; then with the spatula resting on the thickened edge draw the
+spatula away from it with gentle pressure, and the foil will follow in a
+roll.
+
+[Illustration: FIG. 9.]
+
+The old method of using rolls, ropes, and tapes or strips is the same,
+but we will describe one method of using tapes. (See Fig. 9.) A _strip_
+is a single thickness of foil in ribbon form; a strip folded lengthwise
+once, twice, or more forms a _tape_ of two, four, or more thicknesses of
+foil. The tin foil should be cut into strips and folded into tapes
+proportioned in width and thickness to the size of the cavity. One end
+of the tape is carried to the bottom of the cavity and then forced
+against the side opposite the point where we intend to finish; now
+remove the wedge-shaped plugger and catch the tape outside of the
+cavity, and fold another portion against that already introduced,
+letting all the folds extend from the bottom to a little beyond the
+margin. Proceed in this manner, with care and sufficient force, until
+the cavity is full, using for the last folds a small instrument.
+Condense the surface with a large plugger, then go over it carefully
+with a small instrument, and if any part yields, force in a wedge-shaped
+plugger and fill the opening in above-described manner; condense,
+burnish, and trim alternately until the surface is level with the
+cavity-margin. By extending the folds from the orifice to the base of
+the cavity, the liability of the tin to crumble or come out is
+effectually prevented, and by putting it in with a wedge-shaped plugger
+it is pressed out into all depressions of the walls.
+
+A later method of filling with tape or rope is to use wedge-shaped
+pluggers with sharp serrations, filling the _ends_ of the cavity, and as
+the two parts approach each other that next to the wall should be in
+advance of the rest, thus an opening will be left in the center which
+can be filled with a smaller tape or rope.
+
+Another old method: Take a piece of foil and roll it into a hard ball;
+then gradually work it into the cavity, being careful to have
+sufficient around the margin.
+
+Still another suggested method: Roll a piece of foil into a loose ball,
+place it in the cavity, and pass a wedge-shaped plugger into its center.
+This has the effect of spreading the tin toward the walls of the cavity,
+the opening to be filled with folds in a way already described. The
+wedge is used as often as it can be made to enter, filling each opening
+with folds; then condense the surface, trim, and burnish.
+
+[Illustration: FIG. 10.]
+
+The English give the Americans the credit of first using cylinders.
+Anyhow, Dr. Clark, of New Orleans, in 1855, used them made from
+non-cohesive gold, and also from gold and tin in alternate layers. (See
+Fig. 10.)
+
+Cylinders were used which were a little longer than the depth of the
+cavity, introduced with wedge-shaped pluggers around the walls, each one
+being closely adapted to the margin; then another row was added, which
+was forced firmly against the preceding, continuing this process until
+the cavity was full. The wedge, having a smooth end and sides, is forced
+into the center so as to drive the tin toward the sides of the cavity,
+being careful not to split the tooth; the opening is then filled with a
+cylinder. Now force a smaller-sized wedge into the center of the last
+cylinder, and into the opening introduce another cylinder, proceeding in
+this manner until the filling is solid. Then condense the ends of the
+cylinders, trim, and burnish. For the same operation more recent
+pluggers are wedge-shaped, with sharp, deep serrations. In these cases
+the filling is retained by the general form of the cavity and wedging
+within a certain limit, and not by cohesion of the different parts. For
+a time tin cylinders were prepared and put on sale at the dental depots.
+
+As far as we are aware, the first tin foil made use of in operative
+technics was by Dr. F. S. Whitslar, who removed a disk of German silver
+from an ivory knife-handle in 1845, then used hand pressure to fill the
+cavity with tin. In the college course of operative technics tin foil
+can be used, almost to the exclusion of gold foil, to demonstrate the
+manipulation of both cohesive and non-cohesive gold. Shavings scraped
+from a bar of tin are also useful in operative technics; they are more
+cohesive than foil.
+
+
+
+
+
+End of the Project Gutenberg EBook of Tin Foil and Its Combinations for
+Filling Teeth, by Henry L. Ambler
+
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