Treatment outcome in endodontics - The Toronto Study. Phases I and II: Apical surgery

This study prospectively assessed the 4 to 8 yr outcome of apical surgery performed by graduate students in phases I and II of the Toronto Study. The study cohort included 155 teeth in 138 patients. Outcome was assessed by a blinded and calibrated examiner. Clinical and radiographic measures were used for a dichotomous outcome: healed (no signs and symptoms, Periapical Index score less than or equal to 2 or scar), or diseased (presence of signs and symptoms, or Periapical Index score greater than or equal to 3). The recall rate was 85% and the overall healed rate 74%. Healed rate was significantly higher for teeth with small (less than or equal to 5 mm) than larger preoperative lesions (chi(2), p = 0.02). Logistic Regression revealed an increased odds of disease persistence for teeth with larger preoperative lesions (OR = 3.81, Cl = 1.2-12.1), and preoperative root-filling of adequate length (OR = 3.7, Cl = 1.1-11.1). Preoperative lesion size and root-filling length were significant predictors of outcome of apical surgery.