Page 45 - My FlipBook

LIGATURES.
31
hand, the tooth appearing between. The clamp may then be easily
with the other hand.
adjusted ,
This comes
Ligatures. subject up naturally in the consideration
of the dam, but I shall speak of it not only in this connection, but
from various other stand-points. Indeed, the ligature is more valuable
in other work than when used merely to force the dam into place and
hold it there.
To tie silk around the neck of a tooth is generally so painful that it
should be resorted to as infrequently as possible. Where it must be
done, the application of a four per cent, solution of cocaine, freshly
prepared, will do much to alleviate the suffering.
Ordinarily a ligature is not needed in placing the dam ; certainly
it is a rare case where more than two teeth need tying. In placing
the dam over teeth, the edge of each hole naturally turns toward the
incisive edges. If left so, leakage will result. By using a smooth
flat burnisher, or other dull instrument, these edges may be pressed
upward toward the gum till they become inverted. Immediately the
contraction causes the edge to slide up under the free margin of the
gum, so that unless the mouth is abnormally supplied with saliva the
parts will be kept sufficiently dry for all practical purposes. This is
a general principle, which, once noted, will cause the operator to use
ligatures less and less frequently, as he becomes more and more dex-
terous in inverting the edges of the dam around the tooth-neck.
When, because of the shape of the tooth or the superabundance of
saliva, this cannot be relied on, a ligature is essential. It might seem
to tell how to tie a but there are numerous in-
unnecessary ligature,
stances where a little more knowledge would benefit one who has but
one way of doing this seemingly simple thing.
In the first place, how can the cord be tied tightest? and where is
the best place to have the knot ? It is easiest to tie a tight ligature
around the central incisor, and the difficulty increases as the posterior
teeth are approached. This is presuming that the knot is placed
along the labial or buccal festoon. The reason is that while the hands
or molar the cheek
are free at the median line, in the bicuspid region
tension in one direction. There is a method, however, which
prevents
overcomes this. Suppose that the cavity be in the approximal sur-
In around the first
face of a second bicuspid. placing the ligature
then around the first
bicuspid, pass it first between the two bicuspids,
toward the buccal surface.
bicuspid so that the two ends protrude
Make a surgeon's double twist, and before drawing the knot tightly pass
the proper end between the cuspid and bicuspid. The two ends may
and the knot because both hands
now be grasped tightened readily,
have free play. The knot thus occurs between the cuspid and bi-
cuspid. The second tie is made in the same way, except that a single