Etiology of dental caries

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Etiology of dental caries

  1. 1. Etiology of Dental Caries 上海交通大学医学院 附属第九人民医院 黄正蔚 牙体牙髓病科
  2. 2. Etiology is the study of causation. Derived from the Greek αἰτιολογία "giving a reason for" 九院牙体牙髓病科 黄正蔚
  3. 3. 九院牙体牙髓病科 黄正蔚
  4. 4. What is this disease? Color form Texture 九院牙体牙髓病科 黄正蔚
  5. 5. To find the causes … 九院牙体牙髓病科 黄正蔚
  6. 6. Cause of dental caries? 九院牙体牙髓病科 黄正蔚
  7. 7. 虫 齿龋 = 齿 + 禹 (虫 ) 九院牙体牙髓病科 黄正蔚
  8. 8. Where arethose worms ? 九院牙体牙髓病科 黄正蔚
  9. 9. Other explanations ? Might erosion be one cause? 九院牙体牙髓病科 黄正蔚
  10. 10. Where isthe acid ? 九院牙体牙髓病科 黄正蔚
  11. 11. 17th Century Anton van Leeuwenhook 九院牙体牙髓病科 黄正蔚
  12. 12. 九院牙体牙髓病科 黄正蔚
  13. 13. Louis Pasteur九院牙体牙髓病科 黄正蔚
  14. 14. chemico-parasitic hypothesis —— WD. Miller(1890) 化学细菌学 说 九院牙体牙髓病科 黄正蔚
  15. 15. dietary carbohydrates oral bacteria acid production solubilizecalcium phosphate caries 九院牙体牙髓病科 黄正蔚
  16. 16. Bacteriafrom plaque Sugar Acid Acid Healthy Decay Tooth 九院牙体牙髓病科 黄正蔚
  17. 17. Miller’s experiments :teeth + bread/carbohydrates + saliva demineralizationteeth + meat/lipids + saliva non-demineralizationteeth + bread + boiled saliva non-demineralization 不脱矿 脱矿 九院牙体牙髓病科 黄正蔚
  18. 18. Evidences for caries as an infectious disease 1. No bacteria no caries germfree rats Sound teethBacteria seperated from caries inoculated ? 九院牙体牙髓病科 黄正蔚
  19. 19. Evidences for caries as an infectious disease 2. Caries developed with bacteria inoculated inoculatedStreptococci seperated from caries lesion caries 九院牙体牙髓病科 黄正蔚
  20. 20. Evidences for caries as an infectious disease 3. Antibiotics inhibited caries Penicillin caries McClure & Hewitt 1946 九院牙体牙髓病科 黄正蔚
  21. 21. Evidences for caries as an infectious disease 4. Bacteria found in all caries specimensCaries = lesion infected with bacteria microscopically 九院牙体牙髓病科 黄正蔚
  22. 22. Dentinal Liquefactiontubules focus 九院牙体牙髓病科 黄正蔚
  23. 23. Carious human molar infected affected 九院牙体牙髓病科 黄正蔚
  24. 24. 九院牙体牙髓病科 黄正蔚
  25. 25. 九院牙体牙髓病科 黄正蔚
  26. 26. Conclusiondental caries may be caused bymembers of the commensal oralmicroflora 九院牙体牙髓病科 黄正蔚
  27. 27. But …For any microbe to be consideredresponsible for a given condition Koch’s principles 郭霍原则 九院牙体牙髓病科 黄正蔚
  28. 28. Koch’s postulates The microbe should be found in all cases 九院牙体牙髓病科 黄正蔚
  29. 29. Koch’s postulates The microbe should be grown on artificial media 九院牙体牙髓病科 黄正蔚
  30. 30. Koch’s postulates A pure subculture should produce the disease 九院牙体牙髓病科 黄正蔚
  31. 31. And… A high antibody titre to the microbe should be detected 九院牙体牙髓病科 黄正蔚
  32. 32. What’s then? No single microbe has beenfound which completely satisfies Koch’s postulates for caries 九院牙体牙髓病科 黄正蔚
  33. 33. Hypothesis on caries ecological plaque hypothesis Caries is a result of a shift in the balance of the resident microflora 生态菌斑学说 九院牙体牙髓病科 黄正蔚
  34. 34. Reevaluation of the microbial aetiology of dental caries S. oralis Re-Fermentable Neutral S. sanguis mineralization sugar pH Enviromental Ecological Change Change S. mutans De- Low Acid Lactobacilli mineralization pH 九院牙体牙髓病科 黄正蔚
  35. 35. Stephan curve 九院牙体牙髓病科 黄正蔚
  36. 36. multifactorialdental caries disease 九院牙体牙髓病科 黄正蔚
  37. 37. Introduction Host“Plaque-Host-Substrate” theory 九院牙体牙髓病科 黄正蔚
  38. 38.  Factor 1 Microbiota not only Bacteria 九院牙体牙髓病科 黄正蔚
  39. 39. Definitions Dental plaque ( 菌斑 ) Materia alba ( 软垢 ) Pellicle ( 获得性膜 ) Calculus ( 牙结石 ) 九院牙体牙髓病科 黄正蔚
  40. 40. Dental plaqueDental plaque is the soft, nonmineralizedbacterial deposit which forms on teeth anddental protheses that are not adequatelycleaned. ------ LÖe 1965 九院牙体牙髓病科 黄正蔚
  41. 41. Dental plaqueMicroscopically, plaque is simply confluentcolonies of microorganisms connected by amatrix consisting predominantly ofbacterial and salivary polymers. 九院牙体牙髓病科 黄正蔚
  42. 42. What is dental plaque…  Bacteria deposit  On hard surfaces  Bacteria + matrix 九院牙体牙髓病科 黄正蔚
  43. 43. 九院牙体牙髓病科 黄正蔚
  44. 44. erythrosin stained 九院牙体牙髓病科 黄正蔚
  45. 45. Materia albabacterial aggregations, leucocytes anddesquamated oral epithelial cellsaccumulating at the surface of plaque andteeth, but lacking the regular internalstructure observed in dental plaque. 九院牙体牙髓病科 黄正蔚
  46. 46. Differences betweenmateria alba and plaque  Bacteria composition  Internal structure  Adherence strength 九院牙体牙髓病科 黄正蔚
  47. 47. Pelliclean organic film derived mainly from thesaliva and deposited on the tooth surface. 九院牙体牙髓病科 黄正蔚
  48. 48. Calculuscalcified dental plaque, it is always covered with a superficial layer of noncalcified plaque. 九院牙体牙髓病科 黄正蔚
  49. 49. Chemical composition of dental plaque (biofilm) 11 microorganisms > 2X10 per gram per wet weightDental plaque (biofilm) extracellular matrix 九院牙体牙髓病科 黄正蔚
  50. 50. Function of extracellular matrix  carbohydrate reserve  framework of the biofilm  inflammation-inducing, toxic substances 九院牙体牙髓病科 黄正蔚
  51. 51. Chemical composition of dental plaque (biofilm) microorganisms Protein 45%Dental plaque Organic Carbohydrate 15% (biofilm) content extracellular matrix Lipid 12% Inorganic content (Ca, P) 九院牙体牙髓病科 黄正蔚
  52. 52. Formation of dental plaque 九院牙体牙髓病科 黄正蔚
  53. 53. Formation of dental plaque1 hr 30 d 九院牙体牙髓病科 黄正蔚
  54. 54. Influence factors  Diet  Age  Salivary factors  Oral hygiene  Tooth alignment  Systemic disease  Host factors 九院牙体牙髓病科 黄正蔚
  55. 55. Acquired enamel pellicle Initial colonization九院牙体牙髓病科 黄正蔚
  56. 56. Micro-colonies 九院牙体牙髓病科 黄正蔚
  57. 57. Microcolonies coalescing 九院牙体牙髓病科 黄正蔚
  58. 58. 九院牙体牙髓病科 黄正蔚
  59. 59. Filamentous bacteria九院牙体牙髓病科 黄正蔚
  60. 60. “corn-cob” associations九院牙体牙髓病科 黄正蔚
  61. 61. Plaque formation Acquired enamel pellicle formation Initial adherence and subcequent proliferation Further aggregation 九院牙体牙髓病科 黄正蔚
  62. 62. Formation Mechanisms Co-aggregationReversible adhesion Irreversible adhesion ENAMEL 九院牙体牙髓病科 黄正蔚
  63. 63. Formation Mechanisms Plaque formation Detachment ENAMEL 九院牙体牙髓病科 黄正蔚
  64. 64. 九院牙体牙髓病科 黄正蔚
  65. 65. Remember… Attachment, growth, removal and reattachment of bacteria is a continuous and dynamic process Dental plaque will undergo continuous reorganization 九院牙体牙髓病科 黄正蔚
  66. 66. Biofilm ( 生物膜 ) 九院牙体牙髓病科 黄正蔚
  67. 67. Bacteria living in planktonic (free swimming) or in biofilm (dental plaque)? 九院牙体牙髓病科 黄正蔚
  68. 68. Batch culture Biofilm 九院牙体牙髓病科 黄正蔚
  69. 69. 九院牙体牙髓病科 黄正蔚
  70. 70. 九院牙体牙髓病科 黄正蔚
  71. 71. definition Surface-associated bacterial community-forming microcolonies surrounded by amatrix of exopolymers 九院牙体牙髓病科 黄正蔚
  72. 72. Dental plaque ? Biofilm 九院牙体牙髓病科 黄正蔚
  73. 73. Why study biofilm? Attached planktonicBiofilm cells (liquid phase) cells Biofilm Sum of constitutivecommunities populations 1 + 1 2 九院牙体牙髓病科 黄正蔚
  74. 74. Researches revealed …cells growing as biofilm haveunique properties, some of whichhave great clinical significance 九院牙体牙髓病科 黄正蔚
  75. 75. General propertiesProtection from host defense and predatorsProtection from desiccationProtection from antimicrobial agents Surface-associated phenotype Slow growth rate Poor penetration Inactivation/neutralizationNovel gene expression and phenotypePersistence in flowing systemsSpatial and environmental heterogeneitySpatial organization facilitating metabolic interactionsElevated concentration of nutrients
  76. 76.  Factor 2 Host 九院牙体牙髓病科 黄正蔚
  77. 77.  Tooth morphology 九院牙体牙髓病科 黄正蔚
  78. 78. caries susceptibility66
  79. 79. Tooth morphology  Pits & fissures  Irregularities in arch form  crowding  overlapping 九院牙体牙髓病科 黄正蔚
  80. 80. Tooth composition  Mineralization  Trace elements  fluoride 九院牙体牙髓病科 黄正蔚
  81. 81. Enamel surface is more caries-resistant than the subsurface 九院牙体牙髓病科 黄正蔚
  82. 82.  Host factor : Saliva 九院牙体牙髓病科 黄正蔚
  83. 83.  Effect of desalivation on incidence and extent of caries in animals caries 九院牙体牙髓病科 黄正蔚
  84. 84. Decreased salivary flow and caries in humans Xerostomia 九院牙体牙髓病科 黄正蔚
  85. 85.  Salivary flow rate Salivary composition and caries Salivary buffers Antibacterial factors of Glandular origin 九院牙体牙髓病科 黄正蔚
  86. 86.  Factor 3 Substrate: diet and caries 九院牙体牙髓病科 黄正蔚
  87. 87.  Epidemiological observations 九院牙体牙髓病科 黄正蔚
  88. 88.  Experimental caries of animals Caries susceptibility 九院牙体牙髓病科 黄正蔚
  89. 89.  Controlled human studies: VipeholmMental institution 九院牙体牙髓病科 黄正蔚
  90. 90. Toffee Chocolate Caramel 九院牙体牙髓病科 黄正蔚
  91. 91.  Factor 4 Time 九院牙体牙髓病科 黄正蔚
  92. 92. Thanks! 九院牙体牙髓病科 黄正蔚

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