Page 26 - My FlipBook

12 METHODS OF FILLING TEETH.
latter direction should be followed rigidly, except where the groove
is rather intimated than actually existent. It will sometimes happen
that the anterior and instead of being separated by a
posterior pits,
will be connected a across the In such
ridge, slightly by groove ridge.
a case two courses are open, dependent upon circumstances. Where
the cavities may be made separately of strong retaining shape, they
should be so formed, but in placing the gold the filling may be made
to the other across the This
continuous from one cavity groove.
accomplishes the object with the least loss of substance. Occasionally,
however, the filling would be better retained if the two cavities were
united, in which case the bur or drill may be used. I prefer an
inverted cone bur here, thus forming at once a slight but sufficient
undercut.
I said that the rule cannot be as adhered
prescribed dogmatically
to in the treatment of molars as in the case of bicuspids. This is
explained by the assertion that not infrequently cases present where
it would be useless to extend a fissure- cavity.
Fig. 19 shows a section through a molar. Where the sulci occur
the enamel is seen to have been formed separately over each cusp,
there being deep pits (a). This class of fissures is frequently found in
the mouths of children. To the eye there is no sign of decay, and
there may be none, but the fine probe will be caught all along the line of
the fissure, and These
especially where two sulci cro'ss. imperfections
(a) are not seen in adult mouths, because where they exist cavities
will be formed before These fissures should be and
puberty. opened
of the absence of as as when
filled, regardless decay, systematically
decay is present.
Fig. 19 is from a first superior molar, and the natural pits (a) are
seen and This
anteriorly posteriorly. imperfection more often occurs
in the inferior molars.
In 20 we see a section a molar which has
Fig. through superior
simply rounded grooves as sulci (a), and the enamel is thick over the
dentine at all This class of teeth is found in either jaw, though
points.
more commonly in the upper, and is usually associated with a strong,
fully-developed frame. The teeth are large and the enamel dense.
Should caries appear at one end of a sulcus, it would be unwise to
extend the as described. It is more than that
cavity probable decay
has supervened in consequence of some slight imperfection at the spe-
cial point attacked, to fill which is all that is needed.
To summarize as to crown cavities in molars and I would
bicuspids,
advise as a rule the of but one in the and
placing filling bicuspids
lower molars, cutting out the sulci In the superior molars two
fully.
are to be
fillings placed where a marked ridge separates the anterior
from the posterior pit. Where the intervening groove is fissured, the