Intentional Replantation of a Hopeless Mandibular Molar with a Combined Periodontal–Endodontic Lesion: A Case Report

Intentional replantation (IR) is traditionally considered a last-resort procedure for teeth with an otherwise hopeless prognosis. Although advances in biomaterials have improved clinical outcomes, long-term evidence in teeth with combined periodontal–endodontic lesions (CPEL) and severe mobility remains limited. This case report describes a 12-year outcome of IR in a mandibular molar with a large CPEL, Grade III mobility, and persistent infection despite previous root canal therapy (RCT). A 45-year-old female presented with persistent pain and a draining sinus tract associated with tooth #36 one month after an RCT performed elsewhere. Clinical examination revealed Grade III mobility, probing depths >6 mm, bleeding on probing, and Class III furcation involvement. Radiography showed extensive periradicular and furcal radiolucency (PAI = 5). After obtaining written informed consent, an IR was performed. Atraumatic extraction was followed by root-end resection, retro-preparation using Gates-Glidden burs, and placement of calcium-enriched mixture (CEM) cement as a root-end filling material. The tooth was replanted within 9 minutes. No splinting was used. At two weeks, the infection had resolved, and mobility decreased to Grade II. Complete radiographic healing was observed at 3 years (PAI = 1). Probing depths normalized (