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.