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Colour and Shade Selection in dental practise

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Shade selection is an extremely important aspect of aesthetic dentistry.One must have thorough knowledge of colour and shade selection before carrying out any restorative procedures in patients mouth. A brief seminar on colour and shade selection has been penned down here. Hope it helps u fetch some information regarding shade selection and colour in dentistry.

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Colour and Shade Selection in dental practise

  1. 1. 07/13/18 1
  2. 2. 07/13/18 2 COLOR ANDCOLOR AND SHADESHADE SELECTIONSELECTION - DR. SNEHA RATNANI
  3. 3. Contents • Introduction • Colour • Nature of light • Eye and color perception • Understanding the color of teeth • Shade guide • Sequence of shade selection • References 07/13/18 3
  4. 4. 07/13/18 4 introductio n
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  6. 6. 6 ColorColor Color that is perceived is the result of aColor 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 lighttransmits, reflects or scatters the light from the source, and the interpretation offrom the source, and the interpretation of the result by the human visual systemthe result by the human visual system
  7. 7. 07/13/18 7 “Color is the result of the physical modification of light by colorants as observed by the human eye and interpreted by the brain” (Billmeyer and Saltzman) "Color is the sensation resulting from stimulation of the retina of the eye by light waves of certain lengths” (Webster)
  8. 8. 07/13/18 8 You must have light to see color. If an object absorbs certain light waves, you do not see these as colors If an object reflects certain light waves, you see these as colors Colour is light and light is color
  9. 9. 07/13/18 9 LightLight • Light is a visible electromagnetic energy measured in nanometers or billionth of a meter. • The eye can only see part of the electromagnetic spectrum (wavelengths) • That part 380-750 nanometers (nn) • Pure white light when passed through a prism is broken down into its component wavelength (colors)
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  11. 11. 07/13/18 12 Color MixingColor Mixing Light mixture- primary colorsLight mixture- primary colors red, green, bluered, green, blue Additive mixture system- mixing of two of theAdditive 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 = cyangreen + blue = cyan Pigment Or subtractive mixture systemPigment Or subtractive mixture system yellow, cyan, magentayellow, cyan, magenta
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  13. 13. Munsell system 07/13/18 14
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  17. 17. 07/13/18 18 HueHue Quality by which we distinguish one color family from another.Quality by which we distinguish one color family from another. Referred to as the basic colour.Referred to as the basic colour. Ten hue color familiesTen hue color families 1.R-red 6.BG-bluegreen1.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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  19. 19. It depends on the wave length of the reflected and/ or transmitted light. Short wave length = violet hue Long wave length = red hue Studies show that most natural teeth fall in a hue range between yellow and yellow red. 07/13/18 20
  20. 20. 07/13/18 21 ChromaChroma Degree of saturation of hue. Munsell- “That quality by which we distinguish a strong color from a weak one” High chroma = High amount of hue with little dilution Low chroma= small amount of hue with large amount of dilution. Studies have shown that teeth have a chroma range of 0-7.
  21. 21. 07/13/18 22 ValueValue Value or the brilliance is the relative darkness or lighting of color Value is the only dimension of color that can exist by itself. Value differences are more noticeable and this may have more significance in dental restoration than hue or chroma -tooth with high value looks vital (alive) -tooth with low value looks gray (lifeless)
  22. 22. TRANSLUCENCY Considered as fourth dimension of colour. Human teeth characterised by varying degrees of translucency. Can be defined as gradient between transparent and opaque. Translucency of enamel varies with angle of incidence,surface texture, lustre, illumination. 07/13/18 23
  23. 23. Color ( hue) relationship. PRIMARY HUE: Red, yellow and blue. It is the basis of dental color system. SECONDARY HUE: Any two primary hue, when mixed form a secondary hue. when red and blue are mixed—violet blue and yellow—green yellow and red ---orange 07/13/18 24
  24. 24. COMPLIMENTARY HUE: Colors directly opposite to each other in the color wheel. 07/13/18 25
  25. 25. CEILAB COLOUR SYSTEM • In 1976 the Commission Internationale De I’ Eclairage, an international color research group founded in 1931, published the CEILAB COLOR SYSTEM. In this three dimensional color system, l refers to brightness 07/13/18 26
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  27. 27. MAVERICK COLORS • Color or colors found in dentin but not directly responsible for the dentin color. • Maverick colors combine with basic dentin color and project their resultant effect through the enamel as composite tooth color. • Appear in different areas of dentin • The range of family colors is rather narrow.(yellow , honey yellow , light and dark brown). • Influencevery subtle to extensive depending on their saturation. 28
  28. 28. The eye and color perception • Light enters the eye through the lens and acts on the retina.  RODS: These are located on the edges and few towards the center of the retina. • They are activated more in low light. • They see value and not chroma or hue • This is called scotopic vision. • Rods outnumber cones 19-1
  29. 29.  CONES: These are concentrated near the center of the retina at the fovea. • These are the principal mediators of color • Cones function only in higher light levels which is called photopic vision. • They are more highly innervated for more accurate detail and transmission. • So for shade selection, should be directly in front of the object and looking straight at it to get full color effect.
  30. 30. Perception of color depends on • Observer • Environment • Object.
  31. 31. Observer • The stimulus of light travels through cornea, lens, aqueous and vitreous humors and reaches the cones and rods of the eye. • The cones function for daylight vision and color perception whereas rods are sensitive to the quantity of light perceived. • These stimulus are then sent to the brain where they are computed and interpreted as color.
  32. 32. • Different individuals will make different interpretations of the same stimulus and hence, shade selection is highly dependent on subjective assessment.
  33. 33. Color vision confusion • Genetic. (affects 8% males and 2% females) Absence of cones Shift in the spectral sensitivity Loss of color difference signals _ they have difficulty in discrimination red –green or blue-yellow hue contents of color
  34. 34. • Acquired (any one) FACTORS AFFECTING . -Emotions : affects papillary diameter -Aging: yellowing of cornea affects blue and purple discrimination -Chronic diseases: leukemia, multiple sclerosis, liver disease, alcoholism, diabetes. -Medications: analgesics and antibiotics alters the ability to distinguish colors.
  35. 35. • Therefore dentists should have their color perception tested periodically. • In case of a severe deficiency, assistance from a well trained assistant should be observed for color matching.
  36. 36. Shade selection environment • A full spectrum of light is needed to elicit all the color a tooth is capable of reflecting. • The standard is “summers noon with clear sky daylight” • Hence a need for standardized light source is required resembling standard daylight. -C.R.I >90 is ideal -Color temperature of 5500k • Light source should have a near U.V component
  37. 37. • A 3:1 task to ambient light has been recommended • Intensity should be comfortable to eyes ,too much compromises the ability to discriminate small color differences. • The operatory ceilings, walls, cabinets are reflectors and contribute to intensity and color of ambient lighting must have high munsell value and low chroma. • Neutral grays have been suggested for walls, staffs, clothing and patient drape.
  38. 38. Object and background • The quality of the color of an object (tooth) depends on its ability to absorb, reflect, transmit or refract the light energy falling on it. • Contrast effects: the background considerably affects the perception of color. -simultaneous contrast -actual contrast -spatial contrast
  39. 39. Simultaneous contrast - The light and dark contrasts can be correlated to the surrounding environment like skin tone, hair color and brightness of adjacent soft tissues and teeth -hence brighter shades should be selected for light toned patients and darker shades for pigmented – toned patients -since tooth shades fall in orange hue family , blue or neutral grey back ground should be chosen to precondition the eye.
  40. 40. Same shade is percieved differently due to inflamed gingiva
  41. 41. ACTUAL CONTRAST: Is influenced by the size and chroma . Brighter tooth looks larger while a darker tooth of the same dimensions looks smaller. Darker tooth appears smaller as compared to normal tooth
  42. 42. Spatial contrast • It is discerned when the tooth is observed in different positional relationships. • Recessed teeth look darker while overlapping teeth appear brighter and larger Overlapping tooth looks brighter and larger as Compared to tooth which is recessed
  43. 43. Flouroscense • Defined as the absorption of light by a material and the spontaneous emission of light in a longer wavelength ‘blue’. • Flouroscense in natural tooth occurs primarily in the dentin due to the higher amount of organic material present. • More the dentin flourosces lower is the chroma. • Flouroscense considered as subset of reflectivity. • Flouroscent powders are added to crowns to increase the quantity of light returned back to viewer, to block out discolourations and decrease chroma. 07/13/18 44
  44. 44. Opalescence • A phenomenon where a material appears to be one colour when you observe light reflected from it and looks another colour when you see light transmitted through it 07/13/18 45
  45. 45. Shade selection principles • The patient in upright position, mouth at dentist eye level • Selection should be made when subject tooth and adjacent teeth are clean. • Should be done before any intraoral procedures started. • Hold the shade tab as close to the tooth as possible. • Selection should be made at the start of the appointment.
  46. 46. • Cosmetics should be removed and bright colored clothes covered. • View in many light source as possible and from varying distances. • Do not stare for more than 5 seconds. • Move your eyes away and look at a neutral color (light blue or gray)
  47. 47. Commercial Shade GuidesCommercial Shade Guides • Most convenient and common method of making shade selections • Guides consist of shade tabs – Metal backing – Opaque porcelain – Neck, body, and incisal color • Select tab with the most natural intraoral appearance
  48. 48. Commercial Shade Guides • Vita Classic • Vitapan 3D –Master • Extended Range Shade Guides
  49. 49. Vita Classic Shade Guide A B C D • Very popular shade guide • Tabs of similar hue are clustered into letter groups – A (red-yellow) – B (yellow) – C (grey) – D (red-yellow-gray) • Chroma is designated with numerical values • A3 = hue of red-yellow, chroma of 3
  50. 50. Red/Yellow Yellow Grey Grey Red/Yellow
  51. 51. Vita Classic Shade Guide Manufacturer recommended sequence for shade matching 1. Hue Selection 2. Chroma Selection 3. Value Selection 4. Final Check / Revision
  52. 52. Vita Classic – Step 1 (Hue Selection) • Four categories representing hue – A, yellow-red – B, yellow – C, gray – D, red-yellow-gray • Operator should select hue closest to that of natural tooth • Use area of tooth highest in chroma for hue selection – Difficult to select hue for teeth low in chroma
  53. 53. Vita Classic – Step 2 (Chroma Selection) • Hue selection has been made (B) • Chroma is selected from gradations within the B tabs – B1, B2, B3, B4 • Several comparisons should be made – Avoid retinal fatigue – Rest eyes between comparisons (blue-gray)
  54. 54. Vita Classic – Step 3 (Value Selection) • Use of second, value ordered shade guide is recommended • Value oriented shade guide – B1, A1, B2, D2, A2, C1, C2, D4, A3, D3, B3, A3.5, B4, C3, A4, C4, • Value best determined by squinting with comparisons made at arms length – Decreases light – Diminishes cone sensitivity, increases rod sensitivity – Tooth fading first has a lower value
  55. 55. Vita Classic – Step 4 (Final Check / Revision) • Potential Problem – Following value selection, tabs selected for hue and chroma may not coincide with shade tab selected for value
  56. 56. Vita Classic – Step 4 (Final Check / Revision) • Possible Findings / Solutions – Value of shade tab < natural teeth • Select new shade tab with higher value • Cannot increase value of restoration with extrinsic staining • Will only increase opacity, light transmisison – Value of shade tab > natural teeth • Select new shade tab with lower value (or) • Bridge difference with intrinsic or extrinsic staining
  57. 57. VITAPAN 3D-MASTER Shade Guide
  58. 58. Vita-3D – Step 1 • Determine the lightness level (value) • Hold shade guide to patient’s mouth • Start with darkest group moving right to left • Select Value group 1, 2, 3, 4, or 5
  59. 59. Vita-3D – Step 2 • Select the chroma • From your selected Value group, remove the middle tab (M) and spread the samples out like a fan • Select one of the three shade samples to determine chroma
  60. 60. Vita-3D – Step 3 • Determine the hue • Check whether the natural tooth is more yellowish or more reddish than the shade sample selected
  61. 61. Vita-3D – Step 4 • For more precise shade, intermediate levels for hue, value, and chroma can be given – 2.5M2 = value between 2M2 and 3m2 – 3M1.5 = chroma between 3M1 and 3M2 – 3M2 / 3L2.5 = hue between 3M2 and 3L2.5
  62. 62. Vita-3D – Value Modification • For more precise shade, intermediate levels for value, chroma, and hue can be given – 2.5M2 = value between 2M2 and 3M2
  63. 63. Vita-3D – Chroma Modification • For more precise shade, intermediate levels for value, chroma and hue can be given – 3M1.5 = chroma between 3M1 and 3M2
  64. 64. Vita-3D – Hue Modification • For more precise shade, intermediate levels for value, chroma and hue can be given – 3M2 / 3L2.5 = hue between 3M2 and 3L2.5 2.5
  65. 65. 07/13/18 66
  66. 66. 07/13/18 67
  67. 67. 07/13/18 68 Guidelines for Clinical Shade SelectionGuidelines for Clinical Shade Selection 1.light 2.amount lighting1.light 2.amount lighting 3.location of lighting 4.restricting light3.location of lighting 4.restricting light 5.surrounding colors 6.tone of selection5.surrounding colors 6.tone of selection 7.patient position 8.tooth condition7.patient position 8.tooth condition 9.comparison prcds. 10.selectiodistance9.comparison prcds. 10.selectiodistance 11.verification 12.diagram11.verification 12.diagram 13.photograph13.photograph
  68. 68. 07/13/18 69 1. Light1. Light –– sunlight is the traditional source of lightsunlight is the traditional source of light for performing work involving colorsfor performing work involving colors standard daylightstandard daylight –– northern exposure sunlight innorthern exposure sunlight in the middle portion of the daythe middle portion of the day MetamerismMetamerism –– phenomenon occuring when thephenomenon occuring when the color of the two objects appear to match undercolor of the two objects appear to match under one lighting source but not under a differentone lighting source but not under a different sourcesource
  69. 69. 07/13/18 70 2. Amount of lighting2. Amount of lighting –– the recommendedthe recommended minimal amount of room lighting for properminimal amount of room lighting for proper color matching in the dental office is about 200color matching in the dental office is about 200 feet candles when measured at 30 inches abovefeet candles when measured at 30 inches above the floor. This level of lighting is approximatelythe floor. This level of lighting is approximately the same as that from three ceiling fixture eachthe same as that from three ceiling fixture each containing four 48 tubes installed in a 10ft. Bycontaining four 48 tubes installed in a 10ft. By 10ft. room10ft. room
  70. 70. 07/13/18 71 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 mounted3.3 open perimeter surface mounted fixturesfixtures 4. Restricting light4. Restricting light –– light rays enter the eye,light rays enter the eye, they strike the retina, a layer of nerve fibers, thenthey strike the retina, a layer of nerve fibers, then passes through several layers of cells, finally itpasses through several layers of cells, finally it reaches the rods and conesreaches the rods and cones
  71. 71. 07/13/18 72 5. Surrounding colors5. Surrounding colors –– light strikes an object,light strikes an object, some wavelengths are absorbed by the objectsome wavelengths are absorbed by the object and some are reflectedand some are reflected color of an objectcolor of an object –– light that is actuallylight that is actually reflected by the objectreflected by the object 6. Tone of selection6. Tone of selection –– procedure for shadeprocedure for shade selection should be made at the onset ofselection should be made at the onset of diagnostic appointment when it is determineddiagnostic appointment when it is determined that a ceramic restoration is necessarythat a ceramic restoration is necessary
  72. 72. 07/13/18 73 7. patient position7. patient position –– Clark stated for selecting aClark stated for selecting a shade, it is extremely important that the patientshade, it is extremely important that the patient be in an upright position when the shade isbe in an upright position when the shade is selected so that the teeth may be viewed underselected so that the teeth may be viewed under the same conditions which they will be seen inthe same conditions which they will be seen in business and social lifebusiness and social life 8. tooth condition8. tooth condition –– true color characteristic andtrue color characteristic and appearance of depth transluscency in a naturalappearance of depth transluscency in a natural tooth cannot be correctly perceived unless thetooth cannot be correctly perceived unless the tooth is free of plaque and surface stains. Toothtooth is free of plaque and surface stains. Tooth must be kept moist during shade selectionmust be kept moist during shade selection
  73. 73. 07/13/18 74 9. Comparison9. Comparison procedures- it is best toprocedures- it is best to evaluate prospective colorevaluate prospective color specimens one at a time byspecimens one at a time by holding it next to the toothholding it next to the tooth being matched. Holdingbeing matched. Holding the entire shade guide canthe entire shade guide can cause confusion andcause confusion and difficulty may bedifficulty may be encountered inencountered in determining the bestdetermining the best specimen from such aspecimen from such a large group of samples.large group of samples.
  74. 74. 07/13/18 75 10. Selection distance- a10. Selection distance- a selection made at 3-6 feetselection made at 3-6 feet from the oral cavity isfrom the oral cavity is often more useful, since itoften more useful, since it is representative of theis representative of the conditions under whichconditions under which the patient teeth will mostthe patient teeth will most often be observed.often be observed. 3 ft.
  75. 75. 07/13/18 76 11. Verification- the11. Verification- the importance of having theimportance of having the shade selection processshade selection process performed by a secondperformed by a second individual such as a dentalindividual such as a dental assistant cannot beassistant cannot be overemphasized. Thisoveremphasized. This procedure providesprocedure provides another opinion and helpsanother opinion and helps to compensate forto compensate for individual eye fatigue andindividual eye fatigue and visual color defects.visual color defects.
  76. 76. 07/13/18 77 12. Diagram- the12. Diagram- the location of these toneslocation of these tones of color can beof color can be measured on the toothmeasured on the tooth and the information canand the information can be transferred to abe transferred to a diagram. The form anddiagram. The form and extent of transluscencyextent of transluscency as well as other uniqueas well as other unique characteristic such ascharacteristic such as enamel checks orenamel checks or stained areas can also bestained areas can also be identified andidentified and geographically locatedgeographically located in the diagram.in the diagram.
  77. 77. 07/13/18 78 13. Photographs- these are not accurate13. Photographs- these are not accurate representations of clinical color, they can berepresentations of clinical color, they can be useful in showing the laboratory technicianuseful in showing the laboratory technician the extent of translucency and the magnitudethe extent of translucency and the magnitude and location of surface characteristicsand location of surface characteristics
  78. 78. • Color science is the key to solving the shade selection – color matching problem • Elecronic adjuncts will assist in objectifying observations, still it is the human eye which is most able to discern what is and what is not esthetic and who must ultimately be sattisfied. - Robert c. sproull. 07/13/18 79
  79. 79. REFERENCES  Vimal sikri -Text Book Of Operative Dentistry  Goldstein – esthetic dentistry  Sandesh m. mayker -D.C.N.A: vol 45, no:1,jan 2001:55  Sproull RC.color matching in dentistry. Part II .practical application of applying color.J Prosthetic Dent 1973;29:560  Douglas A.Terry – J Esthet Restor Dent 16:213-226,2004  Luis antonio - J Esthet Restor Dent 16:336-347,2004 • Andrew joiner –tooth color : A review of literature : journal of dentistry
  80. 80. THANK YOU

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