Page 136 - My FlipBook

;22 METHODS OF FILLING TEETH.

we should have been
slowly. Strictly speaking, using heavy foil only,
for some time previous to reaching this place. To fill the actual
corner we should select small pellets, and as soon as these have
brought the filling about half-way from the bottom of the cavity to the
margin, we should return to heavy foil, which because of its form
is peculiarly adapted to our needs here. With it, by proper manipu-
lation, a filing should result which would be without
FIG. 130. a flaw.
Fig. 130 shows a common form of cavity, such
as is sometimes termed a be-
compound cavity,
cause it occupies both crown and approximal sur-
faces. The arrangement for retention is precisely
similar to the last, except that, as we now have
an anchorage in the crown, we need not make
the deep undercut at b. As before, c becomes a
point of interest, greater here than in the last condition. If left as
pictured, with a narrow passage connecting approximal and crown,
the corner will considerable trouble. The
resulting sharp give
similar on the side will not be as bad, though even there
angle palatal
it may be trimmed down with advantage. At c, however, the labial
angle should be removed as indicated by the dotted line, which, if
studied, will be seen to follow the natural curve of the labial border
When
line. filling this cavity, as in the last case, this part will need
extra care. Supposing that all has advanced as in the last, the best
plan will be to give attention to the part of the cavity occupying the
crown, and fill that thoroughly without special reference to the approx-
imal portion. This done, we have reduced the case to exactly what
we had in the last cavity when we came to fill c, and consequently
can now as then. Should we to fill c before attend-
proceed attempt
ing to the crown, we would find it very troublesome. In fact, it would
be necessary to alternate between the approximal and the crown,
much as it often
causing annoyance, especially happens that the posi-
tion of the patient must be altered so as better to see one or the other.
To fill the crown first, simplifies the operation, and is therefore prefer-
able. In these extensive approximal cavities, the gingival border is
a most obstacle to success. To obtain a
always trying perfect margin
to these cases is as difficult as it is essential. I rarely make a deep
groove or undercut here, but rather aim to leave the margin strong
and very slightly beveled. More strictly speaking, instead of beveled
a word to the extreme edge of a I should
usually applied cavity
that I form it continuous with the floor of the This allows
say cavity.
the placing of a fairly large pellet of gold, which, attached to that
secured in the be laid
already palato-gingival extension, may against
and condensed hand
lapped over this gingival margin, and partly by