Page 142 - My FlipBook

128 METHODS OF FILLING TEETH.

covered, and the retaining-points connected, the filling must be
completed with heavy gold cut into very narrow strips, about as
long as the cavity. The finest-pointed plugger, and the hand-
us a which will
mallet, will give filling keep its density of surface
forever. It is the filling of such cavities as these which show whether
the dentist is an artist or merely a mechanic. They are so accessible,
and apparently so easy, that I have seen many men at clinics select
work. Yet work here means the
them for demonstrating rapid rapid
of and
use of too large pieces gold, imperfect condensation of the
with the result that after moderate the gold becomes
gold, usage rough.
The same system practiced where the enlire edge is covered brings
the filling back with a ragged edge turned up, as is seen on the ferrule
of a cane or umbrella.
Sometimes we find an incisor presenting with a brownish spot
which may occur so as to involve the incisive edge. Immediately
upon eruption, though the tooth-substance is imperfectly calcified,
yet it is protected to some extent by the fact that there is a superficial
crust which is more dense than what underlies it. After a few years
this crust may break down, and filling become necessary. It is wiser
to remove all of this imperfection, as the dentine.will be found to be
Where the labial of enamel involved, the
chalky. only plate is
presence of the palatal renders the cavity more simple. I will there-
fore choose for illustration such a cavity, the preparation of which
has required the removal of a part of both surfaces. Fig. 138 shows
the cavity in a central incisor prepared for filling. After removing
all of the defective dentine, the first step toward retention is to make
a rather shallow groove along the whole extent, nearly the full width
of the dentine and not encroaching upon the enamel. This direction
analyzed is found to indicate that this groove is narrower as it
approaches the incisive edge. It is at once seen that already the
shape is retentive, since the filling would be wedged in laterally. It
would be difficult, however, if not impossible, to successfully fill the
so formed, because there is no Moreover,
cavity starting-place.
should any accident in the future fracture either of the frail corners,
would be lost, and a difficult be entailed
the entire filling operation
for the restoration of the tooth. I have in mind a case where I filled
both superior central incisors, having cavities of this nature. Some
years later the lady called with the distal corner of one, lost by frac-
ture, and I was able to build on a contour without removing the
For a firm anchorage, therefore, form a dovetail
original filling. by
extensions in the directions indicated by a, a, in either of which the
filling may be readily started, the arrangement being of such form as
will retain the first
pellet.
It is opportune at this point to indicate how to proceed should the