Page 86 - My FlipBook

tints should be used on tlie labial or buccal surfaces in building tliat por-
tion of the inla}' which may extend rootward beyond the gingival line.
Yellow, the most luminous of the colors, is the one most closely
allied to light, and it is the one used most by the porcelain inlay worker.
It should be used to form the foundation of most inlays. It adds bril-
liancy to brown and gray when added to them. Yellows of a greenish
hue tend to lose their luminosity in yellow light, while yellows of a
reddish hue are most luminous. Two yellows in their deeper tones may
match each other perfectly, but when diluted to give lighter tints they
may differ quite widely ; one may be of a greenish hue, while the other
may tend toward a red.
Blue is used to build the body of the incisal and occlusal portion of
inlays for those teeth with blue incisal edges or cusps. It may be added
to grays with a bluish hue to intensify them. There is a variation in tone
from blues with a greenish hue to those with a reddish hue. The former
with a greenish hue are more luminous and appear to be more translucent.
Green is seldom used alone, but it may be added to yellow to give it
a greenish hue and to blue to increase its translucency. Browns should
be used to build the gingival portion of some inlays and also for the
body of inlays for discolored teeth having a brownish hue. Grays are
principally used to build the middle and incisal and occlusal portion of
these teeth with a grayish hue. They are also used to sadden yellows
and blues.
The various hues of colors are produced by mixing pigments in
various proportions or by superimposing a layer of one pigment upon
another. The intensity of a color is controlled by the intensity of the
pigments used and by the thickness of the layers of pigments. Two or
more shades of a color can be made of the same porcelain by varying
the thickness of the body. Knowledge of this fact is important in the
application of porcelain. For, after porcelain has been applied and fused,
is often found that the color is changed. The trouble may arise
it
from several causes. The layer of enamel may be so thin that it is
highly translucent and light from the underlying layers is readily re-
Hected through it. The underlying layers may be constructed of porce-
lain whose pigments are so intense that they cause the inlay to appear
too dark after the final layer of enamel has been applied.
If the beginner is not familiar with the forma-
^'"^'^ °^ colors, he should purchase a water color out-
JHcthOd of
Ecarning Golor fit. consisting of the three primary colors, red,
Gotnbinaiion. \elIow, blue, and a drawing book with white leaves.
He should first study the variations of a color pro-
duced by decreasing the thickness of the layer of pigment. This is done

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