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.