Color and shade selection


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Color and shade selection

  2. 2. ColorColor that is perceived is the result of alight source, the object that absorbs,transmits, reflects or scatters the lightfrom the source, and the interpretationof the result by the human visualsystem 10/08/12 2
  3. 3. LightForm of visible energy that is part of theradiant energy spectrum. Radiant energypossesses specific wavelengths, which maybe used to identify the type of energy 10/08/12 3
  4. 4. 10/08/124
  5. 5. Color MixingLight mixture- primary colors red, green, blueAdditive mixture system- mixing of two of thelight mixture primary colors red + blue = magenta red + green = yellow green + blue = cyanPigment mixture system yellow, cyan, magenta 10/08/12 5
  6. 6. Munsell Color SystemUsed to describe a definite color system in avisual order systemThree dimension or qualities of color 1.hue 2.value 3.chroma 10/08/12 6
  7. 7. Munsell color system 10/08/12 7
  8. 8. HueQuality by which we distinguish one colorfamily 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 10/08/12 8
  9. 9. ValueQuality by which we distinguish a lightcolor from a dark one (lightness ordarkness), Munsell color system extendsfrom zero to ten, black is zero and white isten 10/08/12 9
  10. 10. ChromaQuality of color by which we distinguish astrong color from a weak one. The degreeof departure of a color sensation from thatof white or gray; the intensity of adistinctive hue, color intensity 10/08/12 10
  11. 11. 10/08/1211
  12. 12. Guidelines for Clinical Shade Selection1.light 2.amount lighting3.location of lighting 4.restricting light5.surrounding colors 6.tone of selection7.patient position 8.tooth condition9.comparison prcds. 10.selectiodistance11.verification 12.diagram13.photograph 10/08/12 12
  13. 13. 1. Light – sunlight is the traditional source oflight for performing work involving colorsstandard daylight – northern exposure sunlightin the middle portion of the dayMetemerism – phenomenon occuring when thecolor of the two objects appear to match underone lighting source but not under a differentsource 10/08/12 13
  14. 14. 2. Amount of lighting – the recommendedminimal amount of room lighting for propercolor matching in the dental office is about 200feet candles when measured at 30 inches abovethe floor. This level of lighting is approximatelythe same as that from three ceiling fixture eachcontaining four 48 tubes installed in a 10ft. By10ft. room 10/08/12 14
  15. 15. 3. location of lighting 3.1 all luminous ceiling 3.2 open perimeter recessed fixtures 3.3 open perimeter surface mounted fixtures4. restricting light – light rays enter the eye, theystrike the retina, a layer of nerve fibers, thenpasses through several layers of cells, finally itreaches the rods and cones 10/08/12 15
  16. 16. 5. surrounding colors – light strikes an object,some wavelengths are absorbed by the objectand some are reflectedcolor of an object – light that is actually reflectedby the object6. tone of selection – procedure for shadeselection should be made at the onset ofdiagnostic appointment when it is determinedthat a ceramic restoration is necessary 10/08/12 16
  17. 17. 7. patient position – Clark stated for selecting ashade, it is extremely important that the patientbe in an upright position when the shade isselected so that the teeth may be viewed underthe same conditions which they will be seen inbusiness and social life8. tooth condition – true color characteristic andappearance of depth transluscency in a naturaltooth cannot be correctly perceived unless thetooth is free of plaque and surface stains. Toothmust be kept moist during shade selection 10/08/12 17
  18. 18. 9. comparison procedures-it is best to evaluateprospective colorspecimens one at a time byholding it next to the toothbeing matched. Holdingthe entire shade guide cancause confusion anddifficulty may beencountered indetermining the bestspecimen from such alarge group of samples. 10/08/12 18
  19. 19. 10. selection distance- aselection made at 3-6 feetfrom the oral cavity isoften more useful, since itis representative of the 3 ft.conditions under whichthe patient teeth will mostoften be observed. 10/08/12 19
  20. 20. 11. verification- theimportance of having theshade selection processperformed by a secondindividual such as a dentalassistant cannot beoveremphasized. Thisprocedure providesanother opinion and helpsto compensate forindividual eye fatigue andvisual color defects. 10/08/12 20
  21. 21. 12. diagram- thelocation of these tonesof color can bemeasured on the toothand the information canbe transferred to adiagram. The form andextent of transluscencyas well as other uniquecharacteristic such asenamel checks orstained areas can also beidentified andgeographically locatedin the diagram. 10/08/12 21
  22. 22. 13. photographs- these are not accuraterepresentations of clinical color, they can beuseful in showing the laboratory technicianthe extent of translucency and the magnitudeand location of surface characteristics 10/08/12 22
  23. 23. Dental Shade GuidesExamples of variouscolor combinationsavailable frommanufacturers ofdenture teeth,restorative resins andporcelains. Thesesamples are comparedwith the natural teethand the closest colormatch is determined 10/08/12 23
  24. 24. Color of the Human TeethClark was the first toaccurately describe thecolor of the human teeth in1931 10/08/12 24
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