Page 164 - My FlipBook

148 THE TREATMENT OF TEETH
is easier to replace. Small pin-head holes on the
approximal surfaces of bicuspids and molars are
particularly suitable cases for gutta-percha—filled
with gold, decay will usually attack the margins
within a year or two. The writer would alwaj-s
expect a gutta-percha filling to last longer than a
gold one in these cases, and, if necessary to replace
it, it can be done in a shorter time.
Some authorities explain the rapid failure of these
small approximal gold fillings to want of extension for
prevention ; others put it down to imperfect manipu-
lation. But the most ardent contourist and believer
in the necessity for freely exposed margins would
not think it right to cut away all the side of a tooth,
and hollow out its interior, in order to convert a
minute cavity into a magnificent contour filling.
And even if the failure of minute gold fillings in
these positions is attributable to imperfect manipu-
lation, it must be admitted that not one dentist in a
thousand can do perfect gold work in the majority
of these cases.
Many labial and buccal cavities may also be
satisfactorily filled with gutta-percha. A cavity for
this material should have a general retaining shape,
and consequently a little more cutting away is
usually needed than for a white cement ; but owing
to the smallness of the cavities generally filled with