Page 268 - My FlipBook

114 THE TECHNICAL PBOCEDUEES IN FILLING TEETH.

cavity better or at a more available angle, enabling the operator
to pack gold more certainly and more securely in certain impor-
tant parts of the cavity. Also such cutting may render the fill-
ing so much more convenient as to save time and much wear and
tear upon both patient and operator.
A second order of convenience form consists of slight under-
cuts situated in angles or other parts of the cavity as starting
points in packing gold, or that will hold the first portions of the
filling material while other portions are being packed, or until
the true retention form of the cavity has been filled. The study
of the use of these conveniences and the wise placing of them, is
especially important, as it assists in starting the filling and
securing the first portions. These pits and grooves are usually
placed in the axio-linguo-gingival and axio-buceo-gingival angles
of proximal cavities, and in similar positions in other cavities.
Removal of eemaining caeious dentin. Generally when the
cavity has been cut to form, no carious dentin will remain. But
in the larger decays it will often be a question whether or not
the pulp will be exposed when all decayed dentin overlaying it
is removed. It is especially an object that we do not cut toward
the pulp until the ca\aty is otherwise well prepared, for the rea-
son that if a pulp exposure is found, the cavity shall be fully
cleaned and ready for the immediate treatment of the pulp in any
way indicated. Then when this stage in cavity preparation has
been reached, the remaining softened dentin is carefully and com-
pletely removed with broad spoon excavators, usually with the
20-9-12. It will often be required that the pulp of a tooth be
exposed for the purpose of making an application to destroy it.
In all of these cases, the overhanging enamel should be removed
and the walls of the cavity completely cleaned and so formed as to
safely hold the temporary filling, before cutting toward the pulp.
In many cases in which pulp exposure is expected, where it is in
doubt, or where a knowledge of the extent of the depth of the
decay seems necessary to the completion of the resistance form
and retention form, it is best to remove the decay at once after
the outline form has been satisfactorily completed. This must
be conditioned, however, on having obtained, in getting the out-
line form, such conditions as will allow immediate treatment of
a possible pulp exposure and the sealing of the cavity without
any considerable further excavating. When all of this has been
done and after the rubber dam is securely in place, lift off the
remaining decay with a large spoon excavator, laying the pulp
bare. If this is properly done, very little pain is induced.