Microbiology aspect in endodontics

1. Microbiology aspect in endodontics

2. Terminology Colonization : the establishment of bacteria or orther microorganism in a living host. Infection : damage the host and produce clinical signs and symptom Pathogenicity : The capacity of organisms to produce disease within a particular host Virulence : the degree of pathogenicity in a host under defind circumstance

4. Entries of bacteria to the pulp system

6. Dental caries

7. DENTAL CARIES the most common pathway to the root canal system for microbes. When the tooth is intact, enamel and dentin protect it against invasion of the pulp space. As caries approaches the pulp, reparative dentin is laid down to avert exposure, but this rarely can prevent microbial entry without caries excavation

8. Dentinal tubules 1 to 4 µm in diameter, bacteria are less than 1 µm in diameter. the protective cementum layer is missing or if it has been lost through trauma, the dentinal tubules may be exposed and may serve as a pathway for microbial invasion of the pulp space. Bacterial movement is restricted by :outflow of dentinal fluid, : odontoblastic processes, : mineralized crystals : macromolecules, including immunoglobulins in the tubules.

16. Anachoresis

17. Polymicrobial Microorganism

18. Polymicrobial the number of microorganisms detected in endodontic infections increased to a range of three to 12 organisms per infected root canal associated with an apical lesion The number of colony forming units (CFU) is usually 102 to 108 A positive correlation exists between the number of bacteria in an infected root canal and the size of periradicular radiolucencies

19. Strict anaerobes: function at low oxidation-reduction potential and grow only in the absence of oxygen, but they vary in their sensitivity to oxygen. Obligate anaerobic bacteria lack the enzymes superoxide dismutase and catalase. Some species of bacteria are microaerophilic; they can grow in the presence of oxygen, but they derive most of their energy from anaerobic energy pathways. Facultative anaerobic bacteria :can grow in the presence or absence of oxygen. Obligate aerobic bacteria : have both superoxide dismutase and catalase and require oxygen for growth

20. Intact teeth with necrotic pulp : strict anaerobes more than 90% of the bacteria ( Sundqvist 1989) The apical 5 mm of carious exposed teeth : 67% of the bacteria were strict anaerobes ( Baumgaetner 1999) Gram-negative bacteria, especially species of Porphyromonas and Prevotella that are dark (black) pigmented, have been associated with endodontic infections.

22. Type of microorganisms found in endodontic Infections

23. Type of microorganisms found in endodontic Infections

25. Failed Endodontic Treatment complete periapical healing occurred in : 94% of roots with negative culture : 68% of cases with positive culture ( Sjogren 1997 ) Enterococcus faecalis has been the predominant microbe in canals undergoing retreatment E. faecalis was found in 77% of cases, confirming that this microbe is the most prevalent species in failed endodontic treatment

28. Bacterial virulence factors Bacteroides ?? polysaccharide capsule ???? virulence factor ???????? (Samaranayake 2002) Porphyromonas endodontalis ?? capsule ?????????????????? phagocytosis ???????? proteolytic capability ?????????????? immunoglobulin G ??? E ??? complement factors C3 ??? C5 ??? ?????????????? toxic metabolic products ???? butyrate ??? propionate ??????????????????????????? endodontic infection Porphyromonas gingivalis ???? collagenase gene, amplicon ?????????????????????????????????????? (Odell, Baumgartner et al. 1999)

29. Type of microorganisms found in endodontic Infections Aerobes Streptococcus sp.: S.mitis, S.salivarius Anaerobic streptococci : Peptostreptococcus Enterococci: E. faecalis Bacteroides sp.: Porphyromonas, Prevotella Provotella nigrescens Actinomyces Fungi: Candida albicans Fusobacteria Spirochetes Biofilm

30. Aerobes Beta hemolytic ??? non-hemolytic streptococci ?????????????? peptidoglycans ???????? lymphokine ???? osteoclast-activating factor, prostaglandin lipoteichoic acid ? ??????? complement?bone resorption S.mitis from root canal infection? bacterial endocarditis

31. Anaerobes: Enterococci ???? facultative bacteria, frequency in Endodontic failure (Ingle and K.Bakland 2002) Common in GI tract streptococcus faecalis ???????????????????????????(resistant to antibiotic) ?????????? benzylpenicillin, ampicillin, clindamycin, metronidazole ??? tetracycline

32. Anaerobes: Enterococci sensitive ??? erythromycin ??? vancomycin (Dahlen, Samuelsson et al. 2000) Molander and Dahlen 2003 :Tx with calcium hydroxide+ erythromycin / tetracycline

33. Anaerobes: Bacteroides ???? strictly anaerobes, short chain, gram negative rods and coccobacilli, common in dental plaque, non motile, no spore ?? polysaccharide capsule ???? virulence factor ? serious anaerobic infection ???? sepsis, abscess ???? endotoxin ??? proteases

34. Anaerobes: Bacteroides Polymicrobial infection (facultative anaerobes ? reduced oxygen? Bacteriodes growth) Sensitive to metronidazole ??? clindamycin Resistance to penicillin (beta-lactamase)

35. Anaerobes: Bacteroides 2 genera ??? Porphyromonas ??? Prevotella Porphyromonas ???? asacharolytic bacteria, short chain, gram negative rods, non motile, no spore P.gingivalis common in subgingival sulcus ? periodontal infection P.endodontalis (first from root canal infection) common in dental root canal, periodontal pocket, dental plaque ?endodontic abscess

36. Anaerobes: Bacteroides Prevotella ???? saccharolytic bacteria, gram negative rods, non motile Prevotella melaninogenica (Bacteroides melaninogenica)= black pigment (melanin) ?????????????? P.intermedia ??????? periodontal disease

37. Anaerobes: Prevotella nigrescens ????????????????? Prevotella intermedius, importance in endodontic infection (Shah (1992), Bae (1997), Dougherty (1998), Baumgartner (1999)) Endotoxin: lipopolysaccharide (LPS)? periapical lesion, pulp necrosis, inflammation, bone resorption, pain, edema (Schein and Schilder(1975), Yamasaki et.al.(1992), Horiba et.al.(1989))

38. Anaerobes: Prevotella nigrescens LPS+Peptidoglycans ???????? hormone-like cytokines? tisssue destruction (Henderson and Wilson (1998), Matsushita et.al. (1998)) ??????? B lymphocytes ??????? complement cascade collagenase and interleukin (macrophage cells) ???? pain mediators ???? histamine, bradykinin ??? prostaglandin

39. Anaerobes: Actinomyces ???? anerobic =microaerophilic gram-positive filamentous bacteria, ?????????????????? non motile, no spore Common in nasophalynx ??? gingival crevice ? 70-80% chronic infection, granulomatous ??? endogenous infection of oral cavity (Samaranayake 2002)

40. Anaerobes: Actinomyces found in endodoctic failure case (resistant to routine antibiotic) (Baumgartner 1991, Gohean 1990, Barnard 1996, Siqueira et.al.2002) sulfer granules exudates, in biopsy? branching filamentous form (acid-fast staining) Tx: surgical curettage or resurgical with long term antibiotic (Gohean, Pantera et al. 1990; Baumgartner and Falkler 1991; Barnard, Davies et al. 1996; Siqueira, Rocas et al. 2002)

41. Fungi Candida albicans Debelian, Olsen et al. 1997 ????? candida ???????????????????????????????? blastospores ??? hyphal structures ?????????????????? dentinal tubule ???

42. Fusobacteria: Fusobacterium nucleatum ???? a Gram-negative, non-spore-forming, non motile, obligatory anaerobic rod, primary root canal infections. (Moraes, Siqueira et al. 2002) All of F nucleatum associated with severe pain, swelling and flare-ups case (Chavez de Paz Villanueva 2002)

43. Spirochetes Oral spirochaete (????????????? ???????????? ???? ???????) non culturable Common in root canal infections, pericoronitis, gingivitis ??? periodontitis (10% in endodontic abscesses). (Dahle, Tronstad et al. 1993)

44. Primary endodontic infection

45. Primary endodontic infection

46. Black pigmented bacteria

47. Black pigmented bacteria

48. Black pigmented bacteria Prevotella P.intermedia P.nigrescense P.tannerae P.multisaccharivorax Porphyromonas P.endodontalis P.gingivalis

49. Fusobacterium nucleatum

50. Spirochete bacteria

51. Secondary endodontic infection

52. Secondary endodontic infection

53. Microbial in root filled teeth

54. Microbial in root filled teeth

55. Microbial in root filled teeth

56. E.feacalis in secondary infection

57. E.feacalis in secondary infection

58. E.feacalis in secondary infection

59. E.feacalis in secondary infection

60. E.feacalis in secondary infection

61. E.feacalis in secondary infection

62. E.feacalis in secondary infection

63. Fungi in secondary infection

64. Fungi in secondary infection

65. Fungi in secondary infection

66. Fungi in secondary infection

67. Biofilms

68. SEM of bacterial cells arranged in a biofilm

70. A cooperative “consortia” of species

71. Biofilms grow and spread

72. Cell-cell communication Communicate with one another in biofilm communities via small diffusible molecules. Adapt & survive various environment stresses. Regulate expression of gene Ability to cause disease

73. Benefits A broader habitat range for growth A more efficient metabolism Increased resistance to stress and antimicrobial agent Enhanced virulence

74. Microbial control in biofilm

75. Irrigants for microbial control

76. Er:YAG LASER

77. Photodynamic with methylene blue

78. Photodynamic with methylene blue

79. Treatment of endodontics infection Debridement of the root canal system Incision and drainage Intracanal medication Analgesics and antibiotics Follow up