Finals lecture amalgam

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Finals lecture amalgam

  1. 1. DENTAL AMALGAM
  2. 2. Terminology Silver paste an alloy, one of the constituent of which is mercury an alloy made by mixing Hg with Ag-Sn dental amalgam alloy
  3. 3. Components 1. Silver ( Ag) -increase expansion - retards setting time - enhances strength - decrease flow - resist tarnish/corrosion
  4. 4. 2. Copper (Cu)- unites with Hg with difficulty
  5. 5. 2. Copper- unites with Hg with difficulty - reduces setting time
  6. 6. 2. Copper- unites with Hg with difficulty - reduces setting time - increases expansion
  7. 7. 2. Copper- unites with Hg with difficulty - reduces setting time - increases expansion - increases strength and hardness
  8. 8. 2. Copper- unites with Hg with difficulty - reduces setting time - increases expansion - increases strength and hardness - reduces flow
  9. 9. 2. Copper- unites with Hg with difficulty - reduces setting time - increases expansion - increases strength and hardness - reduces flow -tarnishes readily
  10. 10. 3. Tin (Sn)
  11. 11. 3. Tin - unites readily with Hg
  12. 12. 3. Tin - unites readily with Hg -retards setting time
  13. 13. 3. Tin - unites readily with Hg -retards setting time -improves plasticity
  14. 14. 3. Tin - unites readily with Hg -retards setting time -improves plasticity -reduces expansion
  15. 15. 3. Tin - unites readily with Hg -retards setting time -improves plasticity -reduces expansion -increases flow
  16. 16. 4. Zinc
  17. 17. 4. Zinc (Zn)- combines readily with Hg
  18. 18. 4. Zinc - combines readily with Hg -causes expansion
  19. 19. 4. Zinc - combines readily with Hg -causes expansion -increases setting time
  20. 20. 4. Zinc - combines readily with Hg -causes expansion -increases setting time -increases flow
  21. 21. 4. Zinc - combines readily with Hg -causes expansion -increases setting time -increases flow -inhibits oxidation
  22. 22. 4. Zinc - combines readily with Hg -causes expansion -increases setting time -increases flow -inhibits oxidation -decreases porosity
  23. 23. Classification
  24. 24. Classification1. Amalgam alloy particle geometry and size
  25. 25. Classification1. Amalgam alloy particle geometry and sizee.g. Lathe-cut – regular, fine microfine cut,
  26. 26. Classification1. Amalgam alloy particle geometry and sizee.g. Lathe-cut – regular, fine microfine cut, Spherical
  27. 27. Classification1. Amalgam alloy particle geometry and sizee.g. Lathe-cut – regular, fine microfine cut, Spherical2. Copper Content
  28. 28. Classification1. Amalgam alloy particle geometry and sizee.g. Lathe-cut – regular, fine microfine cut, Spherical2. Copper Contente.g. Low Copper (conventional amalgam),
  29. 29. Classification1. Amalgam alloy particle geometry and sizee.g. Lathe-cut – regular, fine microfine cut, Spherical2. Copper Contente.g. Low Copper (conventional amalgam), High Copper
  30. 30. Classification1. Amalgam alloy particle geometry and sizee.g. Lathe-cut – regular, fine microfine cut, Spherical2. Copper Contente.g. Low Copper (conventional amalgam), High Copper3. Zinc Content
  31. 31. Classification1. Amalgam alloy particle geometry and sizee.g. Lathe-cut – regular, fine microfine cut, Spherical2. Copper Contente.g. Low Copper (conventional amalgam), High Copper3. Zinc Contente.g. Zinc,
  32. 32. Classification1. Amalgam alloy particle geometry and sizee.g. Lathe-cut – regular, fine microfine cut, Spherical2. Copper Contente.g. Low Copper (conventional amalgam), High Copper3. Zinc Contente.g. Zinc, Zinc-free
  33. 33. Alloy- Mercury Ratio
  34. 34. Alloy- Mercury Ratio irregular particle pack poorly and require a large amount of Hg (50%-60%)
  35. 35. Alloy- Mercury Ratio irregular particle pack poorly and require a large amount of Hg (50%-60%) precapsulated amalgam (spherical)has 42%- 45% mercury
  36. 36. Mercury rich mixtures – uses squeeze cloth to remove excess mercury
  37. 37. Mercury rich mixtures – uses squeeze cloth to remove excess mercury1960 -Eames technique or no squeeze cloth technique
  38. 38. Trituration
  39. 39. Trituration process of manual mixing of alloy with Hg
  40. 40. Trituration process of manual mixing of alloy with Hg done by proportioning mercury and Hg into a mortar and grinding the mixture with a pestle
  41. 41. Trituration process of manual mixing of alloy with Hg done by proportioning mercury and Hg into a mortar and grinding the mixture with a pestle mixing of alloy with mercury
  42. 42. Types of Trituration
  43. 43. Types of Trituration1. Hand
  44. 44. Types of Trituration1. Hand2. Mechanical
  45. 45. Types of Trituration1. Hand2. Mechanical –use of Amalgamator
  46. 46. Types of Trituration1. Hand2. Mechanical –use of Amalgamator reusable capsule
  47. 47. Types of Trituration1. Hand2. Mechanical –use of Amalgamator reusable capsule – a hallow tube with rounded ends constructed as two pieces that could be friction fit or screwed together
  48. 48.  precapsulated (preproportioned)-
  49. 49.  precapsulated (preproportioned)- the components are separated in the capsule by a special diaphragm that is broken when the capsule is placed in an amalgamator.
  50. 50. Reaction
  51. 51. ReactionMercury+Silver-Tin
  52. 52. ReactionMercury+Silver-Tin Silver-Tin phase+ Silver-mercury phase + Tin- mercury phase
  53. 53. ReactionMercury+Silver-Tin Silver-Tin phase+ Silver-mercury phase + Tin- mercury phase Silver-tin phase is called the gamma phase, composed of unreacted alloy particle
  54. 54.  Silver-mercury phase is called the gamma one
  55. 55.  Silver-mercury phase is called the gamma one Tin-mercury phase is called the gamma two
  56. 56.  Silver-mercury phase is called the gamma one Tin-mercury phase is called the gamma two amalgam can be thought of as particles of gamma surrounded by or bonded together by a matrix of gamma1 and gamma2
  57. 57. Hardening of amalgam
  58. 58. Hardening of amalgam2 Phenomena
  59. 59. Hardening of amalgam2 Phenomena1. Solution
  60. 60. Hardening of amalgam 2 Phenomena1. Solution2. Crystallization
  61. 61. Hardening of amalgam 2 Phenomena1. Solution2. Crystallization when Hg comes in contact with amalgam alloy, the particles (gamma) are wet by mercury and begins to absorb it.
  62. 62.  the solution of mercury into silver-tin particles leads to the formation of the surface of Ag-Hg and Sn-Hg phases
  63. 63.  the solution of mercury into silver-tin particles leads to the formation of the surface of Ag-Hg and Sn-Hg phases the crystallization of the gamma1 and gamma2 phases and their subsequent growth leads to hardening of amalgam
  64. 64. Mercury Management
  65. 65. Mercury Management Sources of Mercury Hazards
  66. 66. Mercury Management Sources of Mercury Hazards1. Mercury vapors released from stored materials
  67. 67. Mercury Management Sources of Mercury Hazards1. Mercury vapors released from stored materials2. Amalgamator aerosols
  68. 68. Mercury Management Sources of Mercury Hazards1. Mercury vapors released from stored materials2. Amalgamator aerosols3. Spillage during restoration procedure
  69. 69. Mercury Management Sources of Mercury Hazards1. Mercury vapors released from stored materials2. Amalgamator aerosols3. Spillage during restoration procedure4. Amalgam removal and replacement
  70. 70. 5. Amalgam waste on cotton rolls
  71. 71. 5. Amalgam waste on cotton rolls6. Amalgam and mercury in plumbing and sewer system
  72. 72. 5. Amalgam waste on cotton rolls6. Amalgam and mercury in plumbing and sewer system7. Amalgam scrap container
  73. 73. 5. Amalgam waste on cotton rolls6. Amalgam and mercury in plumbing ans sewer system7. Amalgam scrap container8. Mercury trapped in tiles and carpeting
  74. 74. THATS ALL FOLKS

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