Page 677 - My FlipBook

FILLING MATERIALS. 675

If the pulp is very nearly exposed apply Fletcher's carbolized resin
over the floor of the cavity. For this purpose remove the stopper of
the bottle till by evaporation the carbolized resin has thickened to the
consistence of molasses. Dip a small probe in this thickened mass, so
that a small drop will adhere to the end. This drop mav be then con-
veyed to and spread over the floor of the cavity. This will prevent
contact of the cement with the most sensitive dentin and lessen the
possibility of deleterious action on the pulp.
Where it is possible to apply the rubber dam and excavate thoroughly
the same excellent result with cement may be expected as when it is
used in permanent teeth, but often it is not possible to operate as
thoroughly.
By applying melted paraffin ^ or sandarac varnish to the cement the
rubber dam may be removed sooner than otherwise, and the cement
will be protected from moisture by the coating of paraffin or varnish.
As paraffin is insoluble in any agent that can attack it in the mouth,
the more it is absorljcd by the cement the longer it will protect it from
everything but wear ; therefore, do not be content to merely flow the
melted paraffin over the cement, but hold a heated instrument in contact
with the filling and keep the paraffin melted until all that is possible is
absorbed. If an approximal filling has been inserted pass a very thin
heated spatula between the cement filling and the adjoining tooth to
make sure that the paraffin covers it to its cervical margin.
When the rubber dam cannot be applied, cement may still be used
with success if the cavity can be kept dry with napkins or rolls of
cotton or spunk until it is inserted and quickly covered with melted
paraffin.
Deep cavities may be advantageously lined w itli cement and protected
with paraffin till the cement is hard, when the paraffin mav be removed
and gutta-percha or amalgam inserted.
Cavities ix Incisors.—Decay in deciduous incisors is much more
rare than in the other teeth, and they are lost so early in child life that
it is seldom necessary to fill them. Zinc phosphate cement is the best
filling material for these teeth, because they are so small that it is very
difficult to shape the cavities properly for retaining other materials.
If it is found that cement disintegrates rapidly in approximal cavities,
an attempt should be made to shape them so as to retain gutta-percha.
The first filling of cement may have removed the sensitiveness suf-
ficiently to allow deeper excavating at a subsequent sitting, or there
may have been a deposit of secondary dentin, thus removing the pulp
from danger of exposure in properly shaping the cavity.
Amalgam.—While amalgam is a valuable filling material, its use
' Dr. Bonwill's suggestion.