Page 130 - My FlipBook

126 THE TECHNICAL PROCEDURES IN FILLING TEETH.

than five-eighths of an inch in diameter, in the engine. The
disks should never be allowed to pass the point of con-
tact, as they would quickly ruin the filling by cutting
away the contact point, but should be confined to the
embrasures and the buccal and lingual margins. When this has
been completed satisfactorily, a very fine tape may be passed
a few times over the contact point, rounding it and completing
the polish.
The importance of the form of fillings will be consid-
ered more fully when the causes of caries and the conditions
of its occurrence have been presented.
Filling with Amalgam.
I will preface the consideration of the manipulative proced-
ures in filling with amalgam by saying that every detail of the
cavity preparation should be the same as for filling with gold,
except that convenience points for starting the filling need not
be made. Neither is it quite so explicitly required that conven-
ience forms of the walls for access be so rigidly observed,
though there should not be much difference. If possible, the
anchorage should be stronger than for gold, and as amalgam is
so much used for very badly decayed teeth, especially in bicuspids
and molars from which the pulps have been removed, advantage
should be taken of the pulp chamber to strengthen the anchor-
age. The pulp chamber should be filled solidly with amalgam
to the pulpal orifice of the root canals when using it in pulpless
teeth. With the amalgam we are using nowadays the teeth will
not be discolored if the filling is properly made. The amalgam
exposed upon the surface will discolor up to the margins, but
the amalgam that is in contact with the walls of the
cavity will not discolor, and consequently will not discolor
the tooth. It is only when the amalgam filHng leaks about the
margins that the tooth is discolored by it, and as we can now
use amalgams that do not shrink, discolorations of the teeth will
occur only through imperfect manipulation. The fact that
amalgams used in the past and until very recently would shrink,
causing leakage, is the reason why teeth filled with it have been
so generally discolored. It is not easy, however, to make
mechanically perfect amalgam fillings, and for one to succeed
uniformly requires skill and the utmost care in every detail.