2. Color
Color that is perceived is the result of a
light source, the object that absorbs,
transmits, reflects or scatters the light
from the source, and the interpretation
of the result by the human visual
system
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3. Light
Form of visible energy that is part of the
radiant energy spectrum. Radiant energy
possesses specific wavelengths, which may
be used to identify the type of energy
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5. Color Mixing
Light mixture- primary colors
red, green, blue
Additive mixture system- mixing of two of the
light mixture primary colors
red + blue = magenta
red + green = yellow
green + blue = cyan
Pigment mixture system
yellow, cyan, magenta 10/08/12
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6. Munsell Color System
Used to describe a definite color system in a
visual order system
Three dimension or qualities of color
1.hue
2.value
3.chroma
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8. Hue
Quality by which we distinguish one color
family from another
Ten hue color families
1.R-red 6.BG-bluegreen
2.YR-yellowgreen 7.B-blue
3.Y-yellow 8.PB-purpleblue
4.GY-greenyellow 9.P-purple
5.G-green 10.RP-redpurple
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9. Value
Quality by which we distinguish a light
color from a dark one (lightness or
darkness), Munsell color system extends
from zero to ten, black is zero and white is
ten
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10. Chroma
Quality of color by which we distinguish a
strong color from a weak one. The degree
of departure of a color sensation from that
of white or gray; the intensity of a
distinctive hue, color intensity
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12. Guidelines for Clinical Shade Selection
1.light 2.amount lighting
3.location of lighting 4.restricting light
5.surrounding colors 6.tone of selection
7.patient position 8.tooth condition
9.comparison prcds. 10.selectiodistance
11.verification 12.diagram
13.photograph
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13. 1. Light – sunlight is the traditional source of
light for performing work involving colors
standard daylight – northern exposure sunlight
in the middle portion of the day
Metemerism – phenomenon occuring when the
color of the two objects appear to match under
one lighting source but not under a different
source
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14. 2. Amount of lighting – the recommended
minimal amount of room lighting for proper
color matching in the dental office is about 200
feet candles when measured at 30 inches above
the floor. This level of lighting is approximately
the same as that from three ceiling fixture each
containing four 48 tubes installed in a 10ft. By
10ft. room
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15. 3. location of lighting
3.1 all luminous ceiling
3.2 open perimeter recessed fixtures
3.3 open perimeter surface mounted
fixtures
4. restricting light – light rays enter the eye, they
strike the retina, a layer of nerve fibers, then
passes through several layers of cells, finally it
reaches the rods and cones
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16. 5. surrounding colors – light strikes an object,
some wavelengths are absorbed by the object
and some are reflected
color of an object – light that is actually reflected
by the object
6. tone of selection – procedure for shade
selection should be made at the onset of
diagnostic appointment when it is determined
that a ceramic restoration is necessary
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17. 7. patient position – Clark stated for selecting a
shade, it is extremely important that the patient
be in an upright position when the shade is
selected so that the teeth may be viewed under
the same conditions which they will be seen in
business and social life
8. tooth condition – true color characteristic and
appearance of depth transluscency in a natural
tooth cannot be correctly perceived unless the
tooth is free of plaque and surface stains. Tooth
must be kept moist during shade selection
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18. 9. comparison procedures-
it is best to evaluate
prospective color
specimens one at a time by
holding it next to the tooth
being matched. Holding
the entire shade guide can
cause confusion and
difficulty may be
encountered in
determining the best
specimen from such a
large group of samples.
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19. 10. selection distance- a
selection made at 3-6 feet
from the oral cavity is
often more useful, since it
is representative of the 3 ft.
conditions under which
the patient teeth will most
often be observed.
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20. 11. verification- the
importance of having the
shade selection process
performed by a second
individual such as a dental
assistant cannot be
overemphasized. This
procedure provides
another opinion and helps
to compensate for
individual eye fatigue and
visual color defects.
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21. 12. diagram- the
location of these tones
of color can be
measured on the tooth
and the information can
be transferred to a
diagram. The form and
extent of transluscency
as well as other unique
characteristic such as
enamel checks or
stained areas can also be
identified and
geographically located
in the diagram.
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22. 13. photographs- these are not accurate
representations of clinical color, they can be
useful in showing the laboratory technician
the extent of translucency and the magnitude
and location of surface characteristics
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23. Dental Shade Guides
Examples of various
color combinations
available from
manufacturers of
denture teeth,
restorative resins and
porcelains. These
samples are compared
with the natural teeth
and the closest color
match is determined 10/08/12
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24. Color of the Human Teeth
Clark was the first to
accurately describe the
color of the human teeth in
1931
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