Page 413 - My FlipBook

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ces, the dark colour of the plug formed of any of them is seen
through the enamel of the tooth. I could say a great deal
more upon this subject than I have, and detail a great many
cases, but I do not wish to swell this volume with matter that
must be self-evident to every reflecting mind. I will just men-
tion a composition which has been proposed to be used in plug-
ging the teeth. This is the fusible mixture spoken of by Mr.
Fox, formed by uniting bismuth, eight parts, lead, five parts,
and tin, three parts, which melts at the temperature of boiling
water. This in a state of fusion, has been recommended
after cleaning out the cavity, to pour a drop of it into the
cavity, so as to fill it. But this metal is as objectionable as
lead or tin, and at the temperature required it is apt to injure
the tooth, and lead either to farther decay or to active inflam-
mation of the membrane ; consequently, the practice has
been found pernicious, and is, as far as I know, entirely re-
jected by the profession. Gum mastick, &c. has been used.

Of the manner of Performing the Operation of Plugging
the Teeth.

The first step previously to performing this operation is to
clean out the cavity to be plugged, so that every particle of
decayed or diseased matter shall be removed, and a shape
wiven to the cavity, larger within or at the bottom than the
exteiml open ng, so that the metal may be confined within,
like a dove-tail in a mortise, if but slightly, so the plug may
be retained, or if the cavity is not smaller within than the
external opening, but if this is reversed and the external
opening is larger than the internal, and all the way so, a plug
cannot be retained. To clean and shape the cavity, the
scrapinw instruments and our pointed drills described before,
should be used, especially the drills to shape the cavity.
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