title: Characterization of an ex vivo model for the assessment of root canal disinfection.
abstract: Root canal bacteria in teeth with apical periodontitis were enumerated after extraction and incubation. Canals in 36 teeth were sampled after: S1, incubation for 2 hours (group A), 2 days (group B), 4 days (group C), and 6 days (group D); S2, subsequent incubation for 1 week; S3, canal disinfection; and S4, final incubation for 1 week. Bacterial concentrations were determined by culture (colony-forming unit [CFU]) and epifluorescence-microscopy (EFM) and compared by using pairwise and exact-permutation tests (p < 0.05). CFU counts were lower than EFM counts. CFU counts in S1 were higher in Gp(A) than in Gp(C) (p < 0.004) and Gp(D) (p < 0.02). EFM counts in S1 were higher in Gp(A) than in Gp(C) (p < 0.02). Both enumeration methods showed bacterial counts decreasing from S1 to S2 (p < 0.04). EFM was superior to culture in this ex vivo model. The indigenous flora survived incubation for 6 days, but the adverse effect of initial access would preclude testing of disinfection protocols that require two sessions.
authors.affiliation: Discipline of Endodontics, University of Toronto, Ontario, Canada.
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Villette
authors.forename: Sheela
authors.initials: S
authors.lastname: Manek
authors.forename: Milos
authors.initials: M
authors.lastname: Legner
authors.forename: Edward D
authors.initials: ED
authors.lastname: Fillery
authors.forename: Calvin D
authors.initials: CD
authors.lastname: Torneck
authors.forename: Bettina R
authors.initials: BR
authors.lastname: Basrani
authors.forename: Shimon
authors.initials: S
authors.lastname: Friedman
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000254:growth & development; D015169:Colony Count, Microbial; D019551:Dental Disinfectants / Q000627:therapeutic use*; D003786:Dental Pulp Cavity / Q000382:microbiology*; D003789:Dental Pulp Exposure / Q000382:microbiology; D003804:Dentin / Q000382:microbiology; D006801:Humans; D008422:Materials Testing; D008856:Microscopy, Fluorescence; D010485:Periapical Periodontitis / Q000382:microbiology; D012388:Root Canal Irrigants / Q000627:therapeutic use*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D013997:Time Factors
chemical_list: D019551:Dental Disinfectants; D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite