title: Treatment outcome in endodontics: the Toronto study--phases 3, 4, and 5: apical surgery.
abstract: BACKGROUND
  The long-term outcome of apical surgery performed on root-filled teeth presenting with post-treatment apical periodontitis has been the subject of debate; therefore, current evidence is required to support the prognosis of this important procedure. The objectives of this study were (1) to assess the long-term outcome of apical surgery and (2) to identify significant outcome predictors in Phases 3-5 of the Toronto Study, pooled with the previously reported Phases 1 and 2.
  
  
  METHODS
  The 4- to 10-year outcome of apical surgery was prospectively assessed by a blinded, independent, calibrated examiner and dichotomized as "healed" (periapical index score <or=2 or scar; no signs or symptoms) or "diseased." Teeth presenting without signs or symptoms were classified as "functional." Multivariate analysis was performed to investigate outcome predictors, pooling Phases 3-5 (n = 40) with Phases 1 and 2 (n = 94) for improved power.
  
  
  RESULTS
  Of 261 treated teeth in the pooled sample, 96 were lost to follow-up, and 31 were extracted. Of the remaining 134 teeth (85% recall, excluding 66 teeth that could not be recalled) examined for outcome, 99 teeth (74%) were healed, and 126 teeth (94%) were functional. Three significant (P < .05) outcome predictors were identified: age (odds ratio [OR], 2.5; confidence interval [CI], 1.01-6.00; healed: >45 years, 84%, <or=45 years, 68%), preoperative root-filling length (OR, 3.4; CI, 1.34-8.76; healed: inadequate, 84%; adequate, 68%), and size of the surgical crypt (OR, 1.9; CI, 1.19-3.16; healed: <or=10 mm, 80%; > 10 mm, 53%).
  
  
  CONCLUSIONS
  In this 4- to 10-year cohort study, the outcome was better in subjects >45 years old, teeth with inadequate root-filling length, and crypt size of <or=10 mm.
authors.affiliation: Discipline of Endodontics, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Carmina
authors.initials: C
authors.lastname: Barone
authors.forename: Thuan T
authors.initials: TT
authors.lastname: Dao
authors.forename: Bettina B
authors.initials: BB
authors.lastname: Basrani
authors.forename: Nancy
authors.initials: N
authors.lastname: Wang
authors.forename: Shimon
authors.initials: S
authors.lastname: Friedman
mesh_terms: D000328:Adult; D000367:Age Factors; D001047:Apicoectomy / Q000706:statistics & numerical data; D015331:Cohort Studies; D019232:Dental Restoration Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009864:Ontario; D010485:Periapical Periodontitis / Q000209:etiology* / Q000601:surgery*; D011379:Prognosis; D012184:Retrograde Obturation / Q000706:statistics & numerical data; D019227:Tooth Apex / Q000601:surgery*; D019553:Tooth, Nonvital / Q000150:complications* / Q000601:surgery; D016896:Treatment Outcome