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COLOR AND COLOR AND SHADE SHADE SELECTIONSELECTION

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ColorColor

Color that is perceived is the result of a Color that is perceived is the result of a light source, the object that absorbs, light source, the object that absorbs, transmits, reflects or scatters the light transmits, reflects or scatters the light from the source, and the interpretation from the source, and the interpretation of the result by the human visual of the result by the human visual systemsystem

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LightLight

Form of visible energy that is part of the Form of visible energy that is part of the radiant energy spectrum. Radiant energy radiant energy spectrum. Radiant energy possesses specific wavelengths, which may possesses specific wavelengths, which may be used to identify the type of energybe used to identify the type of energy

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Color MixingColor Mixing

Light mixture- primary colorsLight mixture- primary colors red, green, bluered, green, blueAdditive mixture system- mixing of two of the Additive mixture system- mixing of two of the light mixture primary colorslight mixture primary colors red + blue = magentared + blue = magenta red + green = yellowred + green = yellow green + blue = cyan green + blue = cyan Pigment mixture systemPigment mixture system yellow, cyan, magenta yellow, cyan, magenta

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Munsell Color SystemMunsell Color System

Used to describe a definite color system in a Used to describe a definite color system in a visual order systemvisual order system

Three dimension or qualities of colorThree dimension or qualities of color 1.hue1.hue 2.value2.value 3.chroma3.chroma

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Munsell color systemMunsell color system

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HueHue

Quality by which we distinguish one color Quality by which we distinguish one color family from anotherfamily from another Ten hue color familiesTen hue color families 1.R-red 6.BG-bluegreen 1.R-red 6.BG-bluegreen 2.YR-yellowgreen 7.B-blue2.YR-yellowgreen 7.B-blue 3.Y-yellow 8.PB-purpleblue3.Y-yellow 8.PB-purpleblue 4.GY-greenyellow 9.P-purple4.GY-greenyellow 9.P-purple 5.G-green 10.RP-redpurple5.G-green 10.RP-redpurple

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ValueValue

Quality by which we distinguish a light Quality by which we distinguish a light color from a dark one (lightness or color from a dark one (lightness or darkness), Munsell color system extends darkness), Munsell color system extends from zero to ten, black is zero and white is from zero to ten, black is zero and white is tenten

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ChromaChroma

Quality of color by which we distinguish a Quality of color by which we distinguish a strong color from a weak one. The degree strong color from a weak one. The degree of departure of a color sensation from that of departure of a color sensation from that of white or gray; the intensity of a of white or gray; the intensity of a distinctive hue, color intensitydistinctive hue, color intensity

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Guidelines for Clinical Shade SelectionGuidelines for Clinical Shade Selection

1.light 2.amount lighting1.light 2.amount lighting3.location of lighting 4.restricting light3.location of lighting 4.restricting light5.surrounding colors 6.tone of selection5.surrounding colors 6.tone of selection7.patient position 8.tooth condition7.patient position 8.tooth condition9.comparison prcds. 10.selectiodistance9.comparison prcds. 10.selectiodistance11.verification 12.diagram11.verification 12.diagram13.photograph13.photograph

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1. Light – sunlight is the traditional source of 1. Light – sunlight is the traditional source of light for performing work involving colorslight for performing work involving colorsstandard daylight – northern exposure sunlight standard daylight – northern exposure sunlight in the middle portion of the dayin the middle portion of the dayMetemerism – phenomenon occuring when the Metemerism – phenomenon occuring when the color of the two objects appear to match under color of the two objects appear to match under one lighting source but not under a different one lighting source but not under a different sourcesource

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2. Amount of lighting – the recommended 2. Amount of lighting – the recommended minimal amount of room lighting for proper minimal amount of room lighting for proper color matching in the dental office is about 200 color matching in the dental office is about 200 feet candles when measured at 30 inches above feet candles when measured at 30 inches above the floor. This level of lighting is approximately the floor. This level of lighting is approximately the same as that from three ceiling fixture each the same as that from three ceiling fixture each containing four 48 tubes installed in a 10ft. By containing four 48 tubes installed in a 10ft. By 10ft. room10ft. room

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3. location of lighting3. location of lighting 3.1 all luminous ceiling3.1 all luminous ceiling 3.2 open perimeter recessed fixtures3.2 open perimeter recessed fixtures 3.3 open perimeter surface mounted 3.3 open perimeter surface mounted fixturesfixtures4. restricting light – light rays enter the eye, they 4. restricting light – light rays enter the eye, they strike the retina, a layer of nerve fibers, then strike the retina, a layer of nerve fibers, then passes through several layers of cells, finally it passes through several layers of cells, finally it reaches the rods and conesreaches the rods and cones

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5. surrounding colors – light strikes an object, 5. surrounding colors – light strikes an object, some wavelengths are absorbed by the object some wavelengths are absorbed by the object and some are reflectedand some are reflectedcolor of an object – light that is actually reflected color of an object – light that is actually reflected by the objectby the object6. tone of selection – procedure for shade 6. tone of selection – procedure for shade selection should be made at the onset of selection should be made at the onset of diagnostic appointment when it is determined diagnostic appointment when it is determined that a ceramic restoration is necessarythat a ceramic restoration is necessary

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7. patient position – Clark stated for selecting a 7. patient position – Clark stated for selecting a shade, it is extremely important that the patient shade, it is extremely important that the patient be in an upright position when the shade is be in an upright position when the shade is selected so that the teeth may be viewed under selected so that the teeth may be viewed under the same conditions which they will be seen in the same conditions which they will be seen in business and social lifebusiness and social life8. tooth condition – true color characteristic and 8. tooth condition – true color characteristic and appearance of depth transluscency in a natural appearance of depth transluscency in a natural tooth cannot be correctly perceived unless the tooth cannot be correctly perceived unless the tooth is free of plaque and surface stains. Tooth tooth is free of plaque and surface stains. Tooth must be kept moist during shade selectionmust be kept moist during shade selection

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9. comparison procedures- 9. comparison procedures- it is best to evaluate it is best to evaluate prospective color prospective color specimens one at a time by specimens one at a time by holding it next to the tooth holding it next to the tooth being matched. Holding being matched. Holding the entire shade guide can the entire shade guide can cause confusion and cause confusion and difficulty may be difficulty may be encountered in encountered in determining the best determining the best specimen from such a specimen from such a large group of samples.large group of samples.

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10. selection distance- a 10. selection distance- a selection made at 3-6 feet selection made at 3-6 feet from the oral cavity is from the oral cavity is often more useful, since it often more useful, since it is representative of the is representative of the conditions under which conditions under which the patient teeth will most the patient teeth will most often be observed.often be observed.

3 ft.

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11. verification- the 11. verification- the importance of having the importance of having the shade selection process shade selection process performed by a second performed by a second individual such as a dental individual such as a dental assistant cannot be assistant cannot be overemphasized. This overemphasized. This procedure provides procedure provides another opinion and helps another opinion and helps to compensate for to compensate for individual eye fatigue and individual eye fatigue and visual color defects.visual color defects.

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12. diagram- the 12. diagram- the location of these tones location of these tones of color can be of color can be measured on the tooth measured on the tooth and the information can and the information can be transferred to a be transferred to a diagram. The form and diagram. The form and extent of transluscency extent of transluscency as well as other unique as well as other unique characteristic such as characteristic such as enamel checks or enamel checks or stained areas can also be stained areas can also be identified and identified and geographically located geographically located in the diagram.in the diagram.

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13. photographs- these are not accurate 13. photographs- these are not accurate representations of clinical color, they can be representations of clinical color, they can be useful in showing the laboratory technician useful in showing the laboratory technician the extent of translucency and the magnitude the extent of translucency and the magnitude and location of surface characteristicsand location of surface characteristics

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Dental Shade GuidesDental Shade GuidesExamples of various Examples of various color combinations color combinations available from available from manufacturers of manufacturers of denture teeth, denture teeth, restorative resins and restorative resins and porcelains. These porcelains. These samples are compared samples are compared with the natural teeth with the natural teeth and the closest color and the closest color match is determinedmatch is determined

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Color of the Human TeethColor of the Human Teeth

Clark was the first to Clark was the first to accurately describe the accurately describe the color of the human teeth in color of the human teeth in 19311931

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