Page 13 - My FlipBook

NOMENCLATURE. 9

Class 4.— Cavities in the proximate surfaces of the incisors
and cuspids which do require the removal and restoration of the
mesial or distal angle.
Class 5.— Cavities in the proximate surfaces of the bicuspids
and molars.
Class — Pit and fissure cavities. These cavities are
i.
located in the occlusal surfaces of the bicuspids and molars, in
the occlusal two-thirds of the buccal surfaces of the molars, in the
lingual surfaces of the upper incisors, and occasionally in the
lingual surfaces of the upper molars. They are all pit or fissure
cavities. They occur in surfaces of the teeth that are habitually
clean, except as imperfections of the enamel in the form of pits
or fissures afford an opportunity for the lodgment and fermenta-
tion of debris which causes the beginning of decay. Therefore,
the enamel surface immediately about the cavity being habitually
clean, none of them require extension for the prevention of the
recurrence of decay in their preparation for filling. All that is
required is to remove sufficient enamel to completely uncover
the carious area and to obtain margins sufficiently level and
smooth to give opportunity for a perfect finish of the filling.
Classes 2, 3, 4 and 5 are all smooth-surface cavities. They
all occur in positions in which the surfaces of the teeth are unclean
habitually, and usually have their beginnings in the central por-
tion of the unclean area, with a tendency of the carious action to
spread superficially upon the enamel surface. They, therefore,
all agree in requiring extension for the prevention of the recur-
rence of decay in such a way as to include within the lines of the
enamel margins of the prepared cavity all of that portion of the
surface especially liable to decay.
With respect to manipulative procedures, each of these
classes has its especial peculiarities. For instance. Class 2,
which includes all buccal, labial and lingual cavities, requires in
most cases the use of the Hatch clamp to extend the rubber
dam sufficiently to the gingival, and the method of instrumenta-
tion in their preparation is peculiar to them.
Classes 3, 4 and 5 all agree in requiring the use of the
separator to give room for finishing, because all are proximate
cavities, but each of these classes presents especial peculiarities
in manipulative procedure which will receive attention later.