Page 36 - My FlipBook

32 THE TECHNICAL PROCEDURES IN FILLING TEETH.

the molars the rest will be upon the anterior teeth. When
operating upon the anterior teeth the rest will be found on either
side of the tooth operated upon. Any effort to use the teeth in
the opposite jaw for a rest will be found very unsatisfactory, on
account of the movements of the lower jaw changing the rela-
tion of the rest and the tooth operated upon. Rests upon the
soft tissues should be avoided as much as possible, because they
are unreliable at best, and always unsteady.
In the thumb and palm grasp the shaft of the instrument
is held in the palm of the hand in such manner as to oppose the
working point to the thumb, and the thumb of the same hand is
placed either upon the tooth upon which the operation is per-
formed, or upon an adjacent one, to steady the instrument and
to oppose a counter pressure. This grasp is not oft;^n useful,
except when unusual force is to be applied. Neither can it be
used successfully in very many positions. However, there are
certain operations in which its use is very desirable, and each
student should learn these by careful practice. It is especially
useful with the Case cleaver in removing the enamel from the
teeth for fitting bands for crowns, and may be used upon any of
the upper anterior teeth, and often upon the first and second
molars.
The thumb and palm grasp may be used very successfully
with the chisel in opening cavities in any of the upper anterior
teeth, and as far back as the first molars, though only in a limited
number of positions. The requirement is that when the chisel is
grasped in the palm of the hand and the thumb of the same hand
applied to the tooth operated upon, or the one next to it, the
instrument will come into position to be used effectively. When
these positions are found the chisel can be used much more
effectively than is possible with the pen grasp. It is therefore
desirable that this grasp be practiced at every opportunity, and
its use extended as much as possible.
Sharpening Instruments.

Nothing in dental practice is more important than the care
of the cutting edges of instruments. No man ever yet became
a good and effective dentist until after he had learned to keep his
cutting instruments sharp. It is simply impossible to effectively
prepare cavities for filling without sharp instruments. The dental