Page 203 - My FlipBook

ARSENIOUS ACID. 201

into cavities, preferring a filling of denser material, such as soft-
ened gutta percha, chloro-percha and cotton, zinc cement, etc.,
to confine the arsenic more securely.
Dr. Chas. Truman suggests a mixture of iodoform and arsen-
ious acid as a painless devitalizer under all conditions. It is ap-
plied as follows : After placing the rubber dam in position, dry-
ing cavity, etc., the amount of the arsenious acid it is proposed
to employ is placed upon a glass slide and an equal quantity of
iodoform, or an excess is added and a paste made with a five per
cent, solution of carbolic acid, and the whole carried to the pulp
on a piece of cotton, the size of a pin's head. This is then
covered with a gutta percha cap, or one of platinum, and a tem-
porary filling introduced ; the latter may consist of softened gutta
percha or zinc filling material. Pressure upon the pulp must be
avoided.
Some prefer to wound the pulp, so as to draw blood, before
the application of the arsenical preparation is made, and thus
insure its speedy action. Care is necessary that the arsenic
should be completely secured in the carious cavity, and no por-
tion of it come in contact with the parts outside of the tooth.
In the case of proximal cavities, a roll of bibulous paper, saturated
with sandarach varnish, may be pressed between the teeth, be-
yond the cavity, and thus prevent the arsenical preparation from
coming in contact with the gum and cheek, or gutta percha may
be softened and packed against the margin of the gum in such a
quantity as will fill the interspace. Failure to observe such pre-
cautions may result in violent inflammation involving the alveoli
and causing necrosis of the bone. After the devitalization of the
pulp has been accomplished, it is necessary that every particle of
the arsenic should be removed from the tooth. The effect of
permitting the agent to remain in the tooth for a longer time than
is necessary for the devitalization of the pulp only, is peridental
inflammation. Where several applications of the arsenical prep-
aration fail to produce the desired devitalization, the resistance
thus offered to the influence of the agent may be owing to several
causes a granulated, protective covering, which is formed over
;
the surface of the exposed portion of the pulp, which defends it