re 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