Regenerative endodontic treatment of a necrotic immature taurodont mandibular second molar with endodontic infection

Regenerative endodontic treatment (RET) is a promising alternative to conventional apexification for managing immature permanent teeth with necrotic pulp. This case report describes the successful RET of a mandibular second molar with taurodontism and a C-shaped canal configuration in the mesial root, highlighting the challenges in treating complex anatomical variations. A 12-year-old female presented with spontaneous pain in the left mandibular second molar which had undergone initial root canal therapy previously. Clinical and radiographic examinations, including cone-beam computed tomography (CBCT), confirmed the diagnosis of a previously initiated root canal treatment with symptomatic apical periodontitis, incomplete root development, an elongated pulp chamber consistent with taurodontism, and a C-shaped root canal configuration. A two-visit RET procedure was performed in accordance with the guidelines of the European Society of Endodontology. During the first visit, disinfection was achieved using 1.5% sodium hypochlorite, followed by the placement of calcium hydroxide. At the second visit, the canal was irrigated with 17% ethylenediaminetetraacetic acid, and apical bleeding was induced to form a blood clot scaffold. A collagen matrix was then placed, followed by mineral trioxide aggregate, which was subsequently covered with a glass ionomer liner and finalized with a composite restoration to achieve a coronal seal. At 6-month and 1-year follow-ups, the patient was asymptomatic, with radiographic evidence of apical closure and no periapical pathosis. RET is a viable treatment option for immature molars with anatomical complexities such as taurodontism, with CBCT providing valuable support for accurate diagnosis and treatment planning.