Page 426 - My FlipBook

424 CONSERVATIVE TREATMENT OF THE PULP.

tion of cocain, which may be conveniently conveyed forward by gentle
advancements and withdrawals of this instrument. The best form of
instrument for this purpose is the Swiss broach tempered a little beyond
a spring temper.
A matter of considerable importance in connection with the instru-
ments used in these manipulations is that they be either such as have
not been previously used or that they be thoroughly disinfected previous
to use. If an instrument of this kind is indiscriminately used, having
probably been infected by some purulent case, septic disturbance of the
tissues at the apex is brought about. The safest course is to use a new
broach suited in size and stiffness to the case in hand.
Since cataphoresis has been employed in dentistry it has been fre-
quently used to effect the anesthetization of the pulp by cocain. This
method has certain advantages. The time expended in the procedure
is from ten to thirty minutes. The requirements are that insulation be
perfectly secured ; that the selected voltage be low at the commence-
ment—in most instances from 5 to 10 volts—and be gradually increased
as the pain limit will permit.
The impediments are the usual small size of the foramina and the
density of the pulp walls. When the foramen is large the resistance is
less and the action prompt.
Cocain may be employed in this manner to obtund the parietes of the
cavity and the surface of the pulp, when after the removal of the carious
matter the pulp may be uncovered. The application can then be
renewed to complete the anesthetization of the pulp.
This procedure saves much time and discomfort and also avoids
pain as compared with devitalization by chemical means. It is indi-
cated in cases of severe congestion of the pulj), in M'hich arsenic usually
produces great pain and often is without satisfactory result.
In some instances complete obtundation is not effected throughout
the extent of the pulp. Here, after removal of the part anesthetized
the remainder may be devitalized easily by " White's fiber," which is
the safest arsenical preparation to use under these conditions.
Instillation of cocain by means of a broach may also be efficacious.
A further advantage in this method of treatment is that when the
anesthesia is completed the pulp may be entirely removed and the
canal be filled at the same sitting.
It is sometimes observed, as the result of forcing the current beyond
reasonable limits, that soreness of the peridental membrane follows.
AVhat effect has been produced in this instance is not clearly apparent.
AVhether it is a result of undue pressure of the current upon the apical
tissues or is caused by the interference of cocain with the nutrition of
the parts has not been determined. This effect is mentioned to induce