Page 425 - My FlipBook

DEVITALIZATION AND EXTIRPATION OF THE PULP. 423

of lymph or pus from the exposed surface, the pulp is bathed with a
strong solution of cocain and is then covered with a deep cap filled with
a paste of cocain and oil of cloves hermetically sealed in for several
days, when usually the arsenical paste may be used with much-lessened
danger of irritation.
In these cases, and indeed in all cases, an excellent formula for de-
vitalization will be found in the combination of 10 grams of arsenous
acid ground well with 20 grams of cocain. This is taken upon a minute
pledget of cotton previously charged with oil of cloves or carbolic acid,
which is laid upon the exposed point and then sealed in hermetically,
care being taken to avoid compression by arching over the dressing a
suitable cap, or by fiowing over the dressing a soft paste of one of the
mineral cements. Too much care cannot be taken concerniup: the
protection of the gum from escape of the arsenical preparation, since
serious destruction of the gum and alveolus may be produced by the
exuding of the arsenic.
When there is evidence of the exudation of pus, this is checked by
the application of deliquescent zinc chlorid or by washing with pyrozone.
Usually in such cases the surface of the pulp has become necrotic by
the suppurative process and will not be so repellant of the arsenic as in
ordinary cases.
The time usually required for the action of the arsenic to reach well
toward the apex of the roots is from four to six days. This, however,
depends upon the quantity of the preparation applied and the resistance
of the pulp tissue. As the aim should be to procure the nearly com-
plete death of the pulp l)y one a})plication, the longer period is preferable
as entailing less difficulty and the expenditure of less time than when
shorter intervals arc allowed.
When the application is made to an entirely quiescent pulp it will
often be found that at the end of one or two days a broach may be
passed to the end of single-rooted teeth, when the pulp may sometimes
be removed. In these cases, if the pulp be not then extracted, it will
be found in some instances that at a subsequent period the organ has
apparently recovered its sensitivity. The explanation of this is that the
arsenic apparently paralyzes the nerves of the pulj) without having acted
deeper than the surface. In this case the application should be repeated
for a lengthened period without disturbing the tissue. On removing
the dressings if the broach cannot be passed to the end of the canal
either of two courses may be pursued ; the application may be repeated
without removing the devitalized portion, or a strong solution of cocain
may be carefully instillated until it is conveyed to the apex of the canal
by means of a broach. This procedure is best effected by isolating the
tooth with rubber dam and then filling the pulp chamber with the solu-