Intentional replantation for refractory apical periodontitis in an adolescent mandibular first molar: a case report with 4-year follow-up

Background: Apical periodontitis develops when bacterial infection occurs within the root canal system or periapical tissues. In adolescents, immature permanent teeth often exhibit incomplete canal division and insufficient calcification, which may compromise root canal preparation and obturation. Moreover, when the infection originates from extraradicular biofilms rather than intracanal bacteria, nonsurgical endodontic treatment alone may not be sufficient. In such cases, intentional replantation can provide access for root-end management and removal of extraradicular biofilms, serving as a feasible treatment option when conventional retreatment fails. This report aims to present the clinical rationale, procedure, and long-term outcome of intentional replantation as a conservative management approach for refractory apical periodontitis in an adolescent mandibular molar. Case: A 13-year-old male was referred with a persistent sinus tract on the mandibular right first molar following root canal treatment. Retreatment revealed incomplete canal development with a middle distal canal communicating with the distobuccal and distolingual canals. The previously placed calcium hydroxide with iodoform paste was removed, and the canals were refilled with mineral trioxide aggregate (MTA) based materials. Despite initial resolution, recurrence of the apical lesion, accompanied by sinus tract formation, was confirmed at 9 months. Intentional replantation was then performed with extraoral root-end resection and MTA retrofilling. At the 4-year follow-up, clinical and radiographic evaluations demonstrated complete periapical healing, normal mobility and function, and no evidence of root resorption or ankylosis. Conclusions: Endodontic management of immature adolescent teeth requires particular caution due to anatomical complexities. When apical periodontitis persists despite conventional retreatment, intentional replantation may be considered a predictable and viable treatment option in selected adolescent patients.

Intentional replantation; Adolescent patient; Refractory apical periodontitis; Extraradicular biofilm; Mandibular first molar

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