Page 175 - My FlipBook

FESTOON CAVITIES. 161

reference to Fig. 15 will show has no undercut. The absence of an
undercut allows the use of a foot-plugger, and the pellet may be
packed against and over the upper border. A second and third
pellet similarly packed will avoid the danger of slipping of the clamp.
Besides, by this method the most important part of the cavity is filled
early, before any moisture may have crept in, and the continuance
of the is made For foil should be relied
filling easy. this, heavy
upon exclusively, and fine points with a hand-mallet make the densest
filling.
The most difficult festoon cavity is such as is shown at Fig. 185,
where we see a cuspid, the root of which has been exposed by the
recession of the gum, and subsequent caries has encroached upon it
to the gum-margin. Because of the extensive recession at the labial
side, with possibly no recession at the palatal, it will be difficult to fit
a clamp so that it will not slip. With one or other of the various
forms, however, it may be done. The retentive arrangement is dif-
ferent here. It consists of extensions at a, a, as before, but less deep.
Grooves are to be made along the borders b, b, growing shallower as
they meet at c. The filling is begun in the distal pit, and extended
along one groove toward the point c, then down the next groove,
and into the at c, pellets may be
opposite pit. Then, starting employed
'across from to until the
to cover the floor, building groove groove
bottom of the cavity is completely covered. Then resort to heavy
foil, and work from the point c toward completion. Use fine points
and the hand-mallet, to obtain the densest surface.
FIG 18^
Perhaps I should explain why I prefer the hand-
mallet to the engine or electric mallet in these
cavities. It is because the best results are attain-
able with these power- mallets only when a rest for
the hand holding them can be had. When working
in the crowns of the superior teeth, the hand rests
upon the chin. In the lower jaw the power-mallet
is less convenient, yet a finger of the left hand
be made to serve as a rest or to
may usually guide
the mallet-point. This is still more difficult in festoon cavities, for
which reason I recommend the hand-mallet. The others will make
good fillings where the operator has acquired the skill to manage
them, but where he finds their use awkward he will probably get a
poor result if he persists in using them with the erroneous idea that
they make better fillings. Once more I say it is not the instrument,
but the man, who accomplishes success.
The of festoon cavities in does not vary from
preparation bicuspids
that in the cuspids. In the superior jaw they should, in my opinion,
always be filled with gold ; but in the lower, though gold is prefer-