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PIT AND FISSURE CAVITIES 55
ized and the same evaporated to dryness. The entire cavity outline
should be freshly planed, the margins slightly beveled and a posi-
tively determined cavo-surface angle established. The depth the
bevel angle is to be buried should be determined.
The cavity should be thoroughly swept with cotton, the dust dis-
sipated with a blast from the chip blower and the filling immedi-
ately placed.
Pit Cavities in Buccal and Lingual Surfaces of Molars.
Description. These cavities have their origin in defects in the
enamel on the buccal surface of lower molars and the lingual sur-
face of upper molars.
Instrumentation is the same for the same class and size of cav-
Fig. 21.—Lingual pit cavities.
ities just described on the occlusal surface, excepting perhaps it
may be necessary to use the engine burs in the contra-angle hand
piece, a necessity seldom met with on the occlusal surfaces.
Outline Form. The outline should be carried well out of the
pit or groove and sufficiently extended to meet the general rules
given in the chapter on this subject.
Resistance Form will come up for consideration only when the
outline approaches the occlusal marginal ridge. In such cases if
the occlusal wall is not made up of a sufficient bulk of dentine to
withstand the stress of mastication, the outline should be carried
over the marginal ridge to the occlusal surface, in which case rules
for the outline of this portion of the cavity will be the same as pre-
viously given and applicable to all cavities invading occlusal surfaces.
ized and the same evaporated to dryness. The entire cavity outline
should be freshly planed, the margins slightly beveled and a posi-
tively determined cavo-surface angle established. The depth the
bevel angle is to be buried should be determined.
The cavity should be thoroughly swept with cotton, the dust dis-
sipated with a blast from the chip blower and the filling immedi-
ately placed.
Pit Cavities in Buccal and Lingual Surfaces of Molars.
Description. These cavities have their origin in defects in the
enamel on the buccal surface of lower molars and the lingual sur-
face of upper molars.
Instrumentation is the same for the same class and size of cav-
Fig. 21.—Lingual pit cavities.
ities just described on the occlusal surface, excepting perhaps it
may be necessary to use the engine burs in the contra-angle hand
piece, a necessity seldom met with on the occlusal surfaces.
Outline Form. The outline should be carried well out of the
pit or groove and sufficiently extended to meet the general rules
given in the chapter on this subject.
Resistance Form will come up for consideration only when the
outline approaches the occlusal marginal ridge. In such cases if
the occlusal wall is not made up of a sufficient bulk of dentine to
withstand the stress of mastication, the outline should be carried
over the marginal ridge to the occlusal surface, in which case rules
for the outline of this portion of the cavity will be the same as pre-
viously given and applicable to all cavities invading occlusal surfaces.
