Page 32 - My FlipBook

IS METHODS OF FILLING TEETH.

written than is the method practiced. It is preferable to extend
toward the buccal surface, so that the operator may see his work.
Fig. 27 shows such a cavity in a bicuspid, and the dotted line indicates
the extension advised.
Where the approximal surface is decayed, presenting a large saucer-
of a form most difficult to make retentive without en-
shaped cavity
croaching upon the pulp or producing weak surrounding walls, it
is wise to extend the cavity toward the crown and well across that
the sulci and a at the end.
surface, following making deep pit opposite
Fig. 28 shows a section through a tooth so prepared, a being the pit
depended upon to retain the filling.
A very serious condition is occasionally seen, which has been pro-
duced Under the delusion of saving a tooth from the
artificially.
of being filled, some dentist has filed a "V-shaped self-
necessity
between two teeth, and then inserted a flat, or
cleansing (?) space"
such as is shown in The
flush, filling Fig. 29. patient complains
of constant after meals, caused by the of food into
pain impaction
this "self-cleansing" space, and the removal of the meat-shreds
with a the constant use of which has on a
tooth-pick, brought highly
congested state of the gum. It is plain that the only remedy is to
insert a contour This cannot be done in the small cavity
filling.
surrounded by thick flat-faced walls, as figured. Therefore the cavity
must be extended till the walls are thinned at their
edges, assuming
the shape shown in Fig. 30. A properly contoured filling may then
be made with the assurance that there will be no further complaint after
the gum has healed, which will occur very soon.
FORMATION OF CAVITY BORDERS.
In considering the edge-line of cavities, I shall make a distinction
between the general outline and the actual edge, nominating the one
" "
cavity border" and the other enamel margin." Both are subjects
requiring discussion from different stand- points.
As a general principle, the cavity border must be free from angles,
must be curved. More than this, it should be a continuous curve
rather than a succession of curves. From an esthetic
stand-point,
nothing is more essential than that the eye should rest upon a gently
curving line, rather than upon an angular or scalloped one. Many
operators in their efforts to economize tooth-substance make the mis-
take of results which are A small with
producing unsightly. filling
an odd border is more than one which may be but
conspicuous larger,
which has been placed in a cavity correctly formed. These rules, of
course, apply more especially to such fillings as reach the labial sur-
faces of the anterior teeth. to the molar
They apply, however,
region also, because in this instance esthetics and durability go hand