Page 17 - My FlipBook

7
REMO\ AL OF DECAY.
3
It has been claimed that decay covering a pulp may be left in place
and sterilized with safety and This
advantage. sterilizing is usually
done at the sitting at which the filling is placed. I have followed this
advice in a few cases, where, in the front of the mouth, it seemed best to
take every precaution to avoid destruction of the pulps and consequent
discoloration. In every case I have afterward removed the fillings,
because of a bluish appearance which subsequently presented, showing
that the fact that the were was
despite edges yet perfect, decay progress-
This shows that a will not
ing internally. perfect gold filling stop
decay if carious dentine is left in the cavity. P^ecent re^rts from
Professor Miller are in harmony with this experience, since he shows
that the germicides upon which most reliance has been placed are in-
effectual unless left in a cavity much longer and in greater quantity
than has been our practice. When our chemists shall have dis-
covered for us a sterilizing agent the use of which will assure us of a
discontinuance of carious action, in already carious dentine, then, and
not till then, will there be any argument worth listening to against the
assertion that it is malpractice to fell over decay .
There is, however, a delicate distinction to be made between dentine
which is carious, and that which may be slightly affected because of
its with caries. As fast as caries advances, the dentine
juxtaposition
suffers alteration. This action is physiological, and is nature's method
of defense against the inroads of the enemy. A retrogressive meta-
morphosis occurs. The lime-salts are partly dissolved out, the
dentine returning toward an embryonal condition. If the progress
of the disease be slow, a redeposition of lime-salts occurs, the new
tubuli being built up of a form better able to resist caries. Where
this is successful, we observe that condition which we term "arrested
decay." The surface is brownish in color, and flinty ; the tooth is
safe ; nature has cured the disease. *\Ve may therefore cut down to
a stratum of dentine which is undergoing this change, which is easily
cut, but not, strictly speaking, decayed. It is highly important in
these cases not to excavate deeply enough to expose the pulp. The
operator must have the knowledge to enable him to determine when
to stop. The experienced practitioner recognizes the condition by
sight and touch, but a definite description may serve to guide others.
The softening of non-carious dentine occurs most frequently in
those teeth from which we remove carious dentine in leathery layers.
To excavate such a cavity, use spoon excavators only. Never
unless needed for
employ a hatchet, or a hoe, or an engine-bur,
after the has been removed. With a at
shaping decay spoon begin
a farthest from the pulp, and gently lift the outer edge of
point away
a layer. Having thus disengaged it, proceed to lift it around its whole
circumference, and then work gradually toward the center till it can