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78 THE TECHNICAL PROCEDURES IN FILLING TEETH. ;

backwai'd. This grasp is very convenient for placing the rubber
on the lower bicuspids and first molars, the operator standing
to the right and in front of the patient. For this position, the
head of the patient should be upright.
The fifth grasp is used for placing the dam on the second
and third molars, or where it is necessary to reach far back into
the mouth ; and particularly for placing the rubber over the bow
of a clamp previously placed on either one of these teeth, upper
or lower. In doing this, the dam is first taken between the first
and second fingers of each hand, with the forefuigers and thumbs
on the occlusal side. Then the second, third and fourth fingers
are closed, or nearly closed, and the dam grasped between the
thumbs and second fingers, with the thumbs placed opposite the
second joint of the fingers, or between the first and second joints,
as in Figure 80. Notice that the first fingers are free. With
this grasp, stretch the dam a little and engage the two forefingers
in it close on either side of the hole to be used, and with them
stretch the hole open, as in Figure 81. To the beginner it is
generally necessary that the hole be opened sufficiently wide so
that the tooth to which it is to be applied can be seen through it
but when its use is well learned, the tooth will be found by the
sense of touch. Carry the rubber back into the mouth and pass
it over the tooth with the forefingers, the one on the buccal, the
other on the lingual, and engage one edge of the hole between the
teeth, preferablj' the mesial first, and cause it to pass the contact
by a sawing motion. When tlus has passed into the interproxi-
mal space, throw the rubber over the distal surface, and, if it is
a second molar, pass the contact in a similar way. Then carry
each of the finger-ends hard against the gums on either side,
buccal and lingual, of the tooth, completing the first movement.
While holding the forefingers firmly in position, release the dam
with the thumbs and second fingers. The dam will now close
around the tooth, or else it will be felt drawing on the ends of the
forefingers. In the latter case, a little motion of the ends of the
fingers will allow the dam to slide by them and close firmly
around the tooth. Then, and not until then, the fuigers may be
removed, completing the second movement. It often happens
that beginners make this application of the rubber correctly to
the completion of the first movement and then pull the dam off
the tooth in removing the fingers. The dam may now be grasped
again in the same way and the forefingers engaged on either
side of the next hole to be used and it brought over the next tooth
in a similar manner. Notice particularly that the grasp on the