Abstract: Objective: To retrospectively analyze the clinical efficacy of intentional tooth replantation in the treatment of refractory periapical periodontitis of molars, and to provide evidence for the preservation therapy of such affected teeth. Methods: Molar cases that underwent intentional tooth replantation in the General Dentistry Department of Peking University School and Hospital of Stomatology between 2012 and 2024 were selected. The procedure involved minimally traumatic extraction, microscopic assessment of the apical region, resection of the apical 3 mm, retrograde cavity preparation, and retrofilling, followed by replantation into the original socket and stabilization. Regular clinical follow-ups and X-ray examinations were performed postoperatively to evaluate the healing of periapical lesions and the pattern of periodontal ligament healing, and the tooth survival rate at 12 months after surgery was calculated. Results: A total of 18 cases were included, with a follow-up period ranging from 12 to 77 months. The tooth survival rate at 12 months postoperatively was 88.9%(16/18). Success rate was 61.1%(11/18) (asymptomatic with complete periapical lesion healing shown radiographically), while 27.8%(5/18) of cases exhibited no clinical symptoms with lesion size reduction. All periodontal healing patterns were periodontal ligament healing without ankylosis. 2 affected teeth were extracted due to furcation perforation or severe external root infection. Conclusions: Based on the concept of modern microscopic periapical surgery, intentional tooth replantation with strictly standardized operational procedures can serve as an effective supplementary method for the preservation therapy of teeth with periapical lesions.

Key words: intentional replantation, periapical periodontitis, endodontic microsurgery, survival rate, molar