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26 MECHANICAL DENTISTRY AND METALLURGY.
perfect adliesion between the denture and the mucous mem-
brane of the palate—the cast or model should be so carved
that the pressure will be equally distributed. Before dis-
missing- the patient after taking the bite, the mouth, there-
fore, should again be closely examined, and the cast scraped
or carved where additional pressure will be required; that
is, wherever the tissues of the palate are found to be softer
and more yielding than at other pointy For instance, take
a case that is not unusual, where a prominent, hard ridge
is found in the center of the palate. Here it would be
necessary to carve away considerable of the plaster on either
side where the tissues are softer in order to equalize the
pressure, otherwise the finished denture would rock upon
the hard point and thus practically prove a failure. In
nearly all cases a little carving at the posterior edge, from
the plate line forward, will prove advantageous, and in some
cases a groove should be cut around the outside of the ridge
where the parts are yielding, which will form a raised line
or " bead " on the plate just under the margin of the rim.
Also when plain teeth are to be placed directly upon the
gums, as shown in Fig. 21, the cast should be carved at the
points where the teeth are to rest, so that they may set firmly
upon the natural gum, and in fact become slightly imbedded
in the gum tissue when the denture is completed.
The shade of the teeth should also be taken at this visit;
this, of course, should be to match the natural teeth—where
any remain—as accurately as possible; but where all are
missing, a tooth most suitable in shape, size, and color
should be selected. This will be more fully dwelt upon in
the following chapter.