Page 296 - My FlipBook

294 THE OPERATION OF FILLING CA V/TIh'S.

the clamp screw as the operation proceeds and the additional space is
needed.
The matrix is best snited to disto-occlusal cavities. It is sometimes
emj)loyed upon mesio-occlnsal cavities, but as a rule obstructs the lif^ht
and adds little to the convenience of the operatcjr.
Experience has demonstrated that the only satisfactory method of
filling cavities upon the approximal surfaces of the bicuspids and molars
is to restore, by means of fillino; material, the original outline of the
tootii. This is termed " restoration of contour." To do this success-
fully requires artistic sense and mechanical skill of a hitili order, and
an accurate knowledge of the topographic^al anatomy of the teeth. To
the man who has these the operation is easy, but otherwise persistent
efi'ort alone will enable him to ac(piire the ability, "^riie iiiexj)erienced
operator will often do better if he confine himself in the beginning to
but one kind of gold, and that of the cohesive variety. If this be done
he should start the filling in a well-defined groove at the cervical border
of the cavity, and then add, piece by piece, well-annealed foil until the
filling is completoKl. Such a procedure is of necessity slow, but excel-
lent operations can be made by this method. The beautiful and lasting
operations of Varney and Webb and others Avere made in this way.
Class R.— OccluHO-buccal cavities are usually confined to the lower
molars. If they be shallow it is better to fill throughout with ciohe-
sive gold. If, on the other hand, the cavity u]ion the occlusal surface
be deep, non-cohesive gold may be used in part and then cohesive gold
used to fill the channel connecting the two cavities. Such fillings are
subjected to great wear and should be solid (Fig. 2-58).
Class — Ocduso-Umpial.—These cavities are nearly always con-
^S'.
fined to the fii'd and second upper molars, and as a rule are best filled
Fig. 258. Fig. 259. Fig. 260.

Occluso-buccal lilling. Occluso-liugual filling. Mesio-occluso-dislal filling.
with cohesive gold. The channel running into the lingual aspect of
the tooth is not often deep, and non-cohesive gold is contra-indicated
(Fig. 259).
Class T.—Cavities upon the mesial and didal surfaces of the
bicuspids often become confluent with those upon the occlusal sur-
face, and it becomes necessary to fill them as one cavity. Such ope-