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IIO MECHANICAL DENTISTRY AND METALLURGY.
the latter to two of the former), with water. This invest-
ment is brought up over the teetli witli a spatula, so as to
protect them from the flame in the soldering process.
Attaching the Teeth.—When the investment has become
sufficiently dry and hard, the wax is removed, and boiling
water dashed freely over the exposed portion of the plate
and pins of the teeth, so as to thoroughly cleanse them for
soldering. A rim or strip of platinum is now fitted to the
plate and palatine surface of the teeth, below the pins. This
imparts additional strength to the teeth.
The pins of the teeth, which do not already touch the
plate (continuous-gum teeth having unusually long pins for
this purpose) should be bent down over this rim and on to
the plate. When it so happens that a pin will not touch, a
small piece of platinum scrap is folded beneath, so as to
make the connection complete.
With a small brush place borax on the pins and plate at
the points touching, and along the edge between the rim and
plate. Small pieces of pure gold are now placed at all these
points of union. It is all now slowly introduced into a
heated muffle, and brought gently up to a red heat ; then
withdrawn from the furnace and ])laced quickly under the
blowpipe to flow the gold.
After the case is thoroughly soldered and cooled, the in-
vestment is removed from the teeth, taking care to preserve
the base portion for the plate to sit upon during the subse-
cjuent bakings of the body and enamel. The case should
now, after being thoroughly cleansed, be tried in the mouth,
and if any changes have taken place they should be cor-
rected at this time. Everything being correct, the body
can be applied.
Preparing and Applying the Body.—The body, which is
supplied by dental dealers for this purpose, may be mixed
with water in a small porcelain dish to the consistency of