Page 456 - My FlipBook

454 THE TREATMENT AND FILLING OF ROOT CANALS.

Fig. 443.

Bulb syringe.
The toughness of these instruments is remarkable. They are so tem-
pered that they can be bent in any desired direction and when properly
manipulated will readily follow a small and crooked canal to the apex
without danger of breaking off. Two forms : with sharp hooks, for

Fig. 444.

Barbed puli)-extractors and holder.

removing the pulp ; and straight, with the ends slightly roughened,
for carrying a shred of cotton in cleansing out the canal or treat-
ing; alveolar abscess.
The next instruments employed in this connection are what are
known as Donaldson's pulp-canal cleansers (Fig. 446). The points of
these pulp-canal cleansers are reduced so as to enter the canal readily,
and the barbs, which are cut of just sufficient depth to accompli.-^h
their work, are arranged spirally around the shaft, in effect forming a
screw, so that no two cuts are exactly opposite each other (see enlarged
view, a, Fig. 446). With ordinarily careful usage these cleansers will
remove the pulp substance perfectly, without liability to be broken or
to become fastened in the canal. If at any time the instrument does
not withdraw readily from the root, a turn or two to the left (unscrew-
ing) will at once release it.
Made of tough steel piano-wire, with polished rubber handles ; also
without handles, to be used in broach-holder.
The enlarged view of the Gates-Glidden nerve-canal drill (Fig.
447) shows the peculiarity of the safety Glidden point, which will not