Survival and periapical health after root canal treatment with carrier-based root fillings: five-year retrospective assessment.

Abstract

This retrospective study explored survival and periapical healing outcomes in teeth root filled with Thermafil obturators. Root canals of 213 teeth (94 subjects, mean age 48±13years), 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±1years 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%). 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. In this 5±1year 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.