Page 206 - My FlipBook

202 CLASSIFICATION OF DECAYED CAVITIES.

the form of a transverse groove, or along the vertical
depression on the buccal surface of the tooth, or at its
termination. These groove-like decays, extending
along the side of the tooth at or near the margin of the
gum, are ordinarily not very deep; but they burrow
considerably under the enamel, particularly at the side
next the grinding surface. In preparing these cavi-
ties, the projecting portion of the enamel must be
mostly cut away, leaving them but slightly larger

within than at the orifice. These grooves, at their
ends, are shallow; but in their preparation for filling;
they should be cut as deep at the ends as elsewhere,
and, when the main part of the cavity is comparatively
shallow, deeper. Much difficulty is often experienced
in protecting these cavities from moisture while being
filled. The rubber coffer-dam when well applied ac-
complishes the object better than any other appliance;
it is in such cases invaluable.

The method of introducing gold in the form of blocks
into these cavities, is, to set in the first block at the
posterior part of the cavity, and consolidate it, and so
one block after another till the cavity is nearly full;
and then proceed in like manner with the anterior end,
back toward the middle, the blocks, of course, being
permitted to protrude sufficiently for the purposes of
a finish. For filling with crystal gold or adhesive foil,
the method is, to form pits at the end of the groove,