title: Survival and periapical health after root canal treatment with carrier-based root fillings: five-year retrospective assessment.
abstract: OBJECTIVE
  This retrospective study explored survival and periapical healing outcomes in teeth root filled with Thermafil obturators.
  
  
  METHODS
  Root canals of 213 teeth (94 subjects, mean age 48 ± 13 years), instrumented with a step-down technique, irrigated with 5% NaOCl and 10% EDTA and filled with Thermafil and AH Plus sealer, were involved in a recall programme. Teeth were retrospectively re-examined after 5 ± 1 years in a controlled environment. Clinical and radiographic data that were collected included the following: preoperative Periapical Index (PAI) score and signs/symptoms, treatment type, root filling length and presence/absence of voids, restoration type, follow-up PAI score and signs/symptoms. Teeth were considered 'healthy' (PAI ≤ 2, no signs/symptoms) or 'diseased' (PAI ≥ 3, signs/symptoms present, retreated, extracted for endodontic reasons). Two PAI-calibrated examiners assessed outcomes blinded to preoperative status. Bivariate and multilevel analyses were performed at level of patient and tooth (α = 5%).
  
  
  RESULTS
  Of 213 teeth treated, 187 (88%) survived and 26 were extracted, six (3%) for persistent endodontic infection (considered 'diseased'), and 20 (9%) for root fracture, periodontal disease or coronal fracture (excluded from analysis). Whilst survival was significantly associated with tooth type (P = 0.015), type of treatment (P = 0.012) and pulpal/periapical diagnosis (P = 0.035), none of these variables were substantiated as survival predictors by the multilevel analysis. A total of 164 of 193 teeth (85%) were assessed as 'healthy', with significantly higher (chi-square; P < 0.04) 'healthy' rates for teeth with PAI score ≤2 and root fillings of adequate length. Multilevel analysis identified PAI score ≤2 (P = 0.002) as the only predictor of periapical health.
  
  
  CONCLUSIONS
  In this 5 ± 1 year retrospective assessment, survival and healing rates after root canal treatment with Thermafil root fillings were comparable to those previously reported for conventional root filling techniques.
authors.affiliation: Endodontic Clinical Section, Department of Biomedical and Neuromotor Sciences (DIBINEM), School of Dentistry, Alma Mater Studiorum University of Bologna, Bologna, Italy.
authors.forename: C
authors.identifier: http://orcid.org/0000-0002-0245-3535
authors.initials: C
authors.lastname: Pirani
authors.affiliation: Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Friedman
authors.affiliation: Endodontic Clinical Section, Department of Biomedical and Neuromotor Sciences (DIBINEM), School of Dentistry, Alma Mater Studiorum University of Bologna, Bologna, Italy.
authors.forename: M R
authors.initials: MR
authors.lastname: Gatto
authors.affiliation: Endodontic Clinical Section, Department of Biomedical and Neuromotor Sciences (DIBINEM), School of Dentistry, Alma Mater Studiorum University of Bologna, Bologna, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Iacono
authors.affiliation: Endodontic Clinical Section, Department of Biomedical and Neuromotor Sciences (DIBINEM), School of Dentistry, Alma Mater Studiorum University of Bologna, Bologna, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Tinarelli
authors.affiliation: Endodontic Clinical Section, Department of Biomedical and Neuromotor Sciences (DIBINEM), School of Dentistry, Alma Mater Studiorum University of Bologna, Bologna, Italy.
authors.forename: M G
authors.initials: MG
authors.lastname: Gandolfi
authors.affiliation: Endodontic Clinical Section, Department of Biomedical and Neuromotor Sciences (DIBINEM), School of Dentistry, Alma Mater Studiorum University of Bologna, Bologna, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Prati
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010485:Periapical Periodontitis / Q000628:therapy*; D012189:Retrospective Studies; D012387:Root Canal Filling Materials; D012389:Root Canal Obturation; D012390:Root Canal Therapy; D019553:Tooth, Nonvital / Q000628:therapy; D016896:Treatment Outcome
chemical_list: D012387:Root Canal Filling Materials
keywords: Thermafil; clinical outcome; endodontics; prognosis; root canal treatment; survival