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SINGLE PIVOT TEETH AND CROWNS 41

in the furnace. Polish the gold-plate close to the
tooth by means of cuttlefish discs.
In case a tooth is considered likely to be forced out
of its position by the strain of mastication, grind its
mesial and distal surfaces concave until it is embraced
by the neighbouring teeth.
If a single tooth has to be prevented from being
forced outwards, melt a prosthetic pivot to its palatal
surface, for fixing the tooth to both neighbours and
for supporting it. These jwrcelain pivots may be
reinforced by platinum wire when firing.
In case, a root is too thin for a pivot to be intro-
duced, cast both the root part and the pivot for the
artificial tooth in one piece.
This may be done quite as easily as making a
gold inlay.
Take an indirect impression, as commonly taken
for a pivot tooth, grind the tooth, try the prepared
wax-pin and the pivot made Tor receiving the crown
again in the patient's mouth, obtaining thus an exact
impression of the gold inlay which has to be made.
Taking an impression of the internal parts of a
root may frequently present difficulties, as the short
inlay wax cannot be pressed into all the grooves. An
exact impression may be obtained by placing gutta-
percha round a wire point and pressing it into the
root. Now add a little more gutta-percha, and ask
the patient to bite. On the following day the gutta-
percha filling shows the exact impression of the in-
terior of the root.