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THE WAX MODEL 1 99
are procured by obtaining a perfect fit of the inlay to the
cavity walls. The Cavo-surface Angle should be made
obtuse and the bevel angle should not be deeply buried,
thus resulting in a long, thin bevel and a feather edge
to the metal. The bevel should in most cases extend
one-fourth to one-third the thickness of the enamel and
range from 6 to lo Centigrades outward. Margins
over which the wax model has to travel during with-
drawal should be especially highly polished, to avoid
roughness and marring of the wax. Before setting
the inlay, the cavity should be given a bath, first in
chloroform to remove traces of wax and fatty matter,
and then in alcohol. A study of the additional cav-
ity preparations illustrated in Figs. 241 to 248 will be
helpful.
The Wax Model
On completion of the cavity preparation, a model
of the proposed inlay is carved in wax. Special waxes
used for this purpose are Taggart's, Kerr's, and Ransom
and Randolph's Standard. For obtaining the model,
heat the wax in water at a temperature of i38°F.
Mold into a cone (working between the thumb and
fingers until plastic), and force into the cavity until
overfull and perfectly adapted to the walls. Use a
lubricant in the cavity if necessary, such as olive oil
or liquid parafiin, to facilitate easy withdrawal. Have
the patient bite into the wax and chew on it, to ob-
tain the proper occlusal form. Then trim off excess
Fig. 249.
from the occlusal surface, and carve to proper con inlay
tour on approximal surfaces, with Taggart's, Roache's
or other inlay carvers (Fig. 249) until smooth, after which
put on a higher finish with chloroform. After completion of
are procured by obtaining a perfect fit of the inlay to the
cavity walls. The Cavo-surface Angle should be made
obtuse and the bevel angle should not be deeply buried,
thus resulting in a long, thin bevel and a feather edge
to the metal. The bevel should in most cases extend
one-fourth to one-third the thickness of the enamel and
range from 6 to lo Centigrades outward. Margins
over which the wax model has to travel during with-
drawal should be especially highly polished, to avoid
roughness and marring of the wax. Before setting
the inlay, the cavity should be given a bath, first in
chloroform to remove traces of wax and fatty matter,
and then in alcohol. A study of the additional cav-
ity preparations illustrated in Figs. 241 to 248 will be
helpful.
The Wax Model
On completion of the cavity preparation, a model
of the proposed inlay is carved in wax. Special waxes
used for this purpose are Taggart's, Kerr's, and Ransom
and Randolph's Standard. For obtaining the model,
heat the wax in water at a temperature of i38°F.
Mold into a cone (working between the thumb and
fingers until plastic), and force into the cavity until
overfull and perfectly adapted to the walls. Use a
lubricant in the cavity if necessary, such as olive oil
or liquid parafiin, to facilitate easy withdrawal. Have
the patient bite into the wax and chew on it, to ob-
tain the proper occlusal form. Then trim off excess
Fig. 249.
from the occlusal surface, and carve to proper con inlay
tour on approximal surfaces, with Taggart's, Roache's
or other inlay carvers (Fig. 249) until smooth, after which
put on a higher finish with chloroform. After completion of
