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ARTIFICIAL DKNTIRICS; CONTINITOUS-GUM. Ill

cream; this is llicn applied in the plastic stale and is di*^-
tribiited the desired thickness over the surface of the plate
and around tlie necks of the teeth, a spatula or other small
instrument being used for the purpose. After the body
is on, tap the plate occasionally to bring the nmisturc tn the
surface, which should be absorbed with a soft clean napkin.
The body should then be carved with small instruments and
brush to represent the gum, giving the desired fulness, con-
tour, etc., and the roof and rugaj of the mouth should be
reproduced, taking care to keep the crowns and necks of
the teeth clean and well defined. Small, clean cuts with a
small knife blade should then be made, one between each of
the teeth. Commencing with the space between the molars,
the cuts should be made through the body to the rims and
the plate, and should be both external and internal. The
object of this is to prevent movement of any of the teeth
from contraction of the body during baking, compelling the
material to shrink toward the teeth, leaving smooth and
irregular openings where the incisions were made, into
which more of the body is packed and baked.
First Baking.—The plate should now be replaced upon
the base of in^•estment material, upon which it was soldered,
and placed in the upper muffle of the heating furnace. The
Sharp furnace is one of the latest and most approved appli-
ances for this work; it is illustrated both in sections and
complete in Figs. 63, 64. After the case has been placed
in the upper muffle, heat may be applied, slowly at first, but
gradually increased as the case is dried, until the muffle is
red hot, wdien it is removed to the low^er muffle in the fur-
nace, which by this time will be almost to a white heat.
Only a few minutes in this muffle is necessary to bake or
biscuit it. Continue to raise the temperature until the body
presents shining crystals, w'hen the heat may be turned ofi
entirely and the case withdrawn and placed in the upper