Page 213 - My FlipBook

PROTECTION OF THE VITAL PULP 209

and this layer of coagulation is very thin. Again, with this third
class, it will be noted that in addition to the use of the phenol the
eavit.y is given a coat of varnish before applying the oxyphosphate
of zinc cement. This procedure is to prevent the irritating effects
of the phosphoric acid, particularly while the cement is setting.
Again, should the zinc contain any impurities their action on the
pulp is prevented.
* One of the impurities of zinc is arsenic and some
cements are thought to contain traces of this devitalizing agent. The
cavity varnish given above is quite impervious to this element when
it has been thoroughly hardened, a fact which should not be over-
looked when it is desired to prevent the action of arsenic trioxide in
a particular direction in a dental wall.
Fourth Class. In deep-seated cavities Avhere there is a slight
pulp complication from thermal shock and where the thin overljdng
layer of dentine is probably infected to some depth and more deeply
affected in the process of caries, the dentine should be subjected to
quite a continued disinfecting process and a portion of the lost den-
tine restored with a non-conducting material to shield the pulp from
sudden thermal changes.
The Treatment in the Fourth Class of cases is as follows: The
cavity should be flooded with a non-irritating antiseptic, as campho-
l^henique, pure beechwood creosote or oil of cloves. If sealed in the
cavity for twenty-four hours the result will be much better. The
cavity should be then wiped dry with absorbent cotton and a thin
paste of a cement containing sulphate of zinc spread over the den-
tine overlying the pulp. This paste should be thin enough to floAV
to position when coaxed with a small instrument, yet thick enough
to prevent its spreading to surfaces not needed. Over this spread
a layer of oxyphosphate of zinc cement and allow this to set hard be-
fore completing the filling.
In very questionable cases, the entire cavity may be completed
with the cement and the patient dismissed for six months, at the end
of which time, if the pulp is found to be normal, a portion of the ce-
ment may be removed and replaced with a more permanent ma-
terial.
Pulp Preservers and So-Called Mummifiers should be avoided.
Even their name is misleading and such preparations are used with-
out permanent success in the majority of cases. Their use simply
proclaims their users as unskilled laggards who will accept an un-
certainty to avoid a little honest labor in pulp extirpation and root
filling. The entire procedure is diabolical and cannot be condemned