Effect of guided tissue regeneration on the outcome of surgical endodontic treatment of through-and-through lesions : a retrospective study at four year follow-up

Purpose: The main purpose of this retrospective cohort study was to evaluate the 4-year success rate of endodontic surgery in combination with a collagen resorbable membrane for the treatment of through-and-through periradicular lesions. Materials and methods: Patients with one or more teeth with a through-and-through periradicular lesion in need of endodontic surgery were treated. A clinical and radiographic evaluation was performed at 3, 6, 12, 24, 36, and 48 months. The outcome was categorized at 1 and 4-year follow-up as success, failure, and doubtful depending on clinical signs and symptoms and radiographic evaluation. Fisher's exact test was used to evaluate differences between successful and failed cases (P < 0. 05). Results: Forty-three teeth in 33 patients were radiographically and clinically evaluated after 4 years. Thirty-eight teeth were classified as success, 4 teeth as failure, and 1 tooth as doubtful. No statistically significant differences were found in results related to tooth type, tooth location, and presence of post. Conclusions: The association of endodontic surgery and guided tissue regeneration for the treatment of through-and-through periapical lesions leads to excellent outcomes up to 4 years. Standardized criteria are needed to determine the treatment outcome.