Page 112 - My FlipBook

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108 INSTRUMENTS FOR FILLING.

In No. 10 the point has the same shape as .in Nos.
8 and 9. The cutting edge is transverse to the shaft,

and rises by a small neck at a right angle from it.
Six sizes.
Such are the most important forms of excavators
though modifications will be required for particular
cases. While Nos. 8, 9, and 10 are not in extensive
use, a few operators have used them for some years,
and prize them very highly. In many difficult cases
they are far more applicable than any other instru-
ment we have. For instance, in the formation of the
cervical wall of a proximal cavity in any of the teeth,
but particularly in the superior bicuspids and molars,

there is no other instrument so applicable and efficient
as No. 9 : with it, that part of the cavity, so fre-
quently neglected, is just as easily formed as any
other.
Cases will occasionally be presented, in which some
curvature of the shaft of the instrument will be requi-
site. But no more curve should be given to any in-
strument than may be absolutely necessary, for it is
impossible to manipulate with the same precision and
delicacy with curved as with straight instruments.
The degree of curve necessary in any given case will
be determined by the position of the decay on the

tooth, and the location of the latter in the mouth.
Since the first edition of this work was written,