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METHODS OF FILLING TEETH.
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the of have not at the
is exposed throughout, pedicles gum yielded
but retain a normal The
buccal and labial angles, position. gum being
it is evident that if the rubber-dam be
firmly attached at other points,
stretched over such a tooth, it will in consequence of the pedicles
0, a span across, and occupy the line b, b, so that the cavity border
will be below the dam. In many cases it is not only impossible to
force the dam down with a ligature and keep it there, but the effort
the abandonment of the
to do so, by causing hemorrhage, compels
Even where one succeeds in the
operation at that sitting. pressing
rubber and ligature below the border, it rises again when tied, because
if it is not made
becoming taut it must assume the straight line b, b ;
taut, leakage will occur. To overcome this difficulty, it has been
suggested to use copper wire as a ligature.
In a few mild cases this works very well.
The wire ligature is applied about the neck
of the tooth, and the ends twisted till tight.
As with the silk or flax, it follows the line
^' ^> kut with a suitable instrument it may
now be forced below the border of the
cavity, carrying the dam with it, and, being
metallic, it will retain its position.
Where this cannot be accomplished, it becomes impossible to fill
the entire cavity with gold. Two courses are open, either amalgam
alone must be or
depended upon, amalgam may be used up to, and
above the line b, b, the rest of the filled with
slightly cavity being gold
at a In either case a more
subsequent sitting. margin nearly perfect
will be obtained if the napkin is used instead of the rubber-dam, the
gum being occasionally mopped with bibulous paper or spunk during
This will be more
the operation. alluded to in
specially discussing
the manipulation of amalgams.
When it has been decided to employ the dam, it is requisite that it
should be so placed that the patient may suffer least, and the operator
have the for access to all of the
greatest facility obtaining parts cavity.
The first desideratum is that a sufficient number of teeth should be
embraced so that all folds of the rubber shall be well out of the
way.
There should be at least two teeth on each side of the space between
the teeth which are to be filled. This as a general rule will answer
in most cases. It sometimes happens, however, that much will be
gained by embracing five, six, seven, or even more teeth. Cavities
in the posterior surfaces of bicuspids and molars are usually trying
cases, wherein accessibility and good light are essentials best obtained
by stretching the rubber over several teeth. It is usually sufficient
to include the central on the side of the mouth where the
operation is
to be performed.