Page 71 - My FlipBook

FLASKING, VULCANIZING AND FINISHING. —
59
tlie gum that the thin neck of riihber running from the plate
to the tooth or teeth would be too frail to support them,
teeth with gold backings and tongues should be used. In
preparing such a tooth, select a suitable plate tooth and
grind it to fit the plaster model ; then fit the backing and
tongue to the tooth, arrange them upon the cast to secure
the proper bend and angle for the tongue (see Fig. 31),
cement them together, invest, and solder.
That portion of the gold plate to be embedded in the
rubber should have small gold or platinum pin-heads
soldered to it, or it should be perforated in several places
as illustrated,—the latter is probably the best practice,
to secure a better union between the gold and the rubber.

Fig. 31. Fig. 32.

Gold Clasps.—In attaching gold clasps to rubber plates
the same method can be employed, that is, by either attach-
ing small pin-heads or perforating the gold tongue which
is to extend into the rubber. (See Fig. 32.) In making
these attachments they should be so arranged that they
will be well embedded in the rubber when the plate is fin-
ished. In such cases care must be taken in packing the
rubber about the clasps. The space between the pins or
tongue and the cast should be packed well with rubber, so
that when the flask is closed the force will not displace the
tooth or clasp.
Beaded or Grooved Dentures.—For the exclusion of air
and moisture from between the artificial denture and
mucous membrane of the mouth* a bead may be carried
* First recommended by Dr. W. Storer How, of Philadelphia.