Taking shades for dentists

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A presentation looking at the problems with shade taking and some ideas on how to overcome them

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Taking shades for dentists

  1. 1. Mark Oborn RDT LBIDST Of all the things I’ve lost in life , the things I miss the most are my marbles
  2. 2. Shade Matching Subjectivity to Objectivity
  3. 3. We will look at… <ul><li>Colour Theory </li></ul><ul><li>Understanding how a crown is built </li></ul><ul><li>Computer assisted shade analysis </li></ul><ul><li>Practical techniques. </li></ul>
  4. 4. We will look at… <ul><li>Colour Theory </li></ul><ul><li>Understanding how a crown is built </li></ul><ul><li>Computer assisted shade analysis </li></ul><ul><li>Practical techniques </li></ul>
  5. 5. Colour doesn’t exist It is merely our brains interpretation of a series of effects and actions placed on a particular wavelength of light
  6. 6. Colour is affected by… <ul><li>Reflection </li></ul><ul><li>Transmission </li></ul><ul><li>Interference </li></ul><ul><li>Dispersion </li></ul><ul><li>Scattering </li></ul>
  7. 7. Reflection <ul><li>Some frequencies of light are reflected while some are absorbed </li></ul>
  8. 8. Transmission <ul><li>Some frequencies of light are transmitted through the tooth while others are absorbed </li></ul>
  9. 9. Interference <ul><li>certain frequencies are amplified while others are disrupted </li></ul>
  10. 10. Dispersion <ul><li>The separation of a polychromatic light wave </li></ul>
  11. 11. Scattering <ul><li>the redirection of certain frequencies of light striking small particles </li></ul>
  12. 12. Summary <ul><li>Reflection – Some frequencies of light are reflected while some are absorbed </li></ul><ul><li>Transmission - Some frequencies of light are transmitted through the tooth while others are absorbed </li></ul><ul><li>Interference - certain frequencies are amplified while others are disrupted </li></ul><ul><li>Dispersion - the separation of a polychromatic light wave </li></ul><ul><li>Scatterin g - the redirection of certain frequencies of light striking small particles. </li></ul>
  13. 13. This means that… <ul><li>One needs to take in to account these effects on a tooth when looking at colour. Otherwise you may THINK you see a colour, but really it is the effects of the interplay of reflection, transmission, dispertion, interferance and scattering. </li></ul>
  14. 14. Reflection Transmission Interference Dispersion Scattering Look at the water in this scene. We know water is a colourless liquid, yet due to these effects it looks everything from black to white and all shades of blue in this photo
  15. 15. We all also have preconceptions Picture a summers day?
  16. 16. Did your picture look anything like either of these?
  17. 17. Now picture the colour Orange?
  18. 18. Which shade of orange did you picture?
  19. 19. The Effects of the Gingiva Look at the dot in the centre, depending on the surrounding colour, the yellow bar at each end looks slightly different. Which is most representative?
  20. 20. Lighting prerequisites for the surgery to help overcome these problems <ul><li>5500-6500K (D65 light source) </li></ul><ul><li>Ra (Colour rendering index) >95 – 1A International scale </li></ul>
  21. 21. OSRAM TABLE OSRAM 965 is one of the best light bulbs to help overcome this
  22. 22. We will look at… <ul><li>Colour Theory </li></ul><ul><li>Understanding how a crown is built </li></ul><ul><li>Computer assisted shade analysis </li></ul><ul><li>Practical techniques </li></ul>
  23. 23. There are many depths of colour on a tooth
  24. 24. Dentine Colour Dentine Effects Enamel Colours Surface Effects
  25. 25. We try to match this with a crown, these are some of the colours we would use at different depths to get a C3
  26. 26. A3 Dark stain D2 White banding Feint orange flecks Translucent incisal This is how shades often are drawn by dentists and technicians alike
  27. 27. Dentine Colour Dentine Effects Enamel Colours Surface Effects But where do these colours all go? AT what depth?
  28. 28. A3 dentine White band on dentine D2 Dentine I recommend breaking the tooth down in to layers, look deep within the tooth. Then map it the DENTINE only.
  29. 29. Orange Enamel TOS10G Enamel TOS58 Opalescent blue TOS10B Surface stain neck and body white striations Next map the ENAMEL only, this avoids too much information on the prescription and gives us a 3D map of where to build the colours
  30. 30. This is how I do it
  31. 35. Images from digital systems
  32. 36. We will look at… <ul><li>Colour Theory </li></ul><ul><li>Understanding how a crown is built </li></ul><ul><li>Computer assisted shade analysis </li></ul><ul><li>Practical techniques </li></ul>
  33. 37. Communication must be taken seriously. Each person can interpret the last person differently with disasterous results Patient wants Dentist says Technician hears “ I want perfect teeth” “ Make the teeth white, symmetrical, straight and in line” Oops a disasterous case!
  34. 38. Use Contrastors for photos General Medical
  35. 39. With black contrasters the incisal architecture is easier to see
  36. 41. Photos to take Full arch in ICP
  37. 43. Photos to take Single tooth, Teeth apart
  38. 44. Notice how different the tooth looks when open and closed, take both images
  39. 45. Photos to take Lingual
  40. 46. This shows us how to map the incisal colours
  41. 47. Photos to take With shade tab
  42. 48. This gives the lab an idea of gradation of colour against a standard
  43. 49. Modify the image properties. Increase contrast and decrease brightness
  44. 50. The various effects then stand out which makes mapping easier
  45. 51. SBO Dental Laboratory 01707 663293 www.sbodentallaboratory.co.uk Precision meets Art Thank you for your attention

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