Page 154 - My FlipBook

I 4 o METHODS OF FILLING TEETH.
so that the enamel thus undermined fractures under the force of mas-
tication and caves in. Frequently, however, the teeth come to us
thoroughly undermined, but with the enamel apparently intact except
at the small orifice along the sulcus. Thus the dentine just under the
cusps, though decayed, might be left in the cavity unless special care
be taken to remove it. A shepherd' s-crook excavator might accom-
plish this, but the result is scarcely desirable, as even where all the
carious dentine is successfully taken away the cusps, unsupported by
dentine, are likely to crush under mastication later on. I therefore
advise the free use of the chisel to thoroughly expose the cavity, and
reach strong borders. With a sharp chisel placed at the points a, a,
of a mallet will remove the enamel
gentle taps overhanging readily
and painlessly. Painlessly, because the enamel is taken off in the
line of fracture, so that the patient finds no concussion from the mallet-
blow. The final arrangement of the cavity is best shown by a
diagrammatic illustration, as seen in Fig. 156. This may be con-
sidered a section through the tooth, and shows first that the cusps
have been cut away so that the filling when inserted covers them suffi-
ciently to afford protection, and secondly we see that in finishing the
no the form of
filling attempt has been made to exactly reproduce
the surface. The is made to resemble a
masticating filling merely
crown in a left smooth and
bicuspid general way, being gently curved,
so that it is readily cleansed.
As to selection of I should lean toward
filling-material, certainly
unless contraindicated circumstances
gold, by peculiar to an individual
case. To pack the gold I should resort to the method of using
oxyphosphate in the bottom of the cavity, pressing in the first pellets
whilst the cement was still This I shall describe more
plastic. particu-
larly when I come to molars. Where a dentist prefers to use amalgam,
It will be seen that no alteration of the will be
cavity required. Neither
need I give any special directions for placing the amalgam, the cavity
being very simple. I should insist on the return of the patient for sub-
sequent polishing.
In Fig. 157 we have a bicuspid from which one cusp has been lost.
When this is the palatal cusp it would be as well not to attempt a full
restoration, but to be satisfied with an approximate contour, so that
the tooth when filled may appear as shown in Fig. 158. This is dia-
grammatic, giving a section through the filled tooth, and indicating
the outer form attained, as well as the relation of the gold to the cavity
itself. Where, however, the cusp which is absent is the labial, it will
not answer to so proceed, for by not reproducing the full cusp we leave
an as the occlusion
ill-shaped tooth to attract attention, especially
would not be reached. Of course the occlusion would not be reached
in the first case either, but being out of si^ht this would be of no im-