Minimally Invasive Endodontic Management Of Fused Teeth: A Case Report

This case highlights the management of acute pulpitis in a fused mandibular molar using minimally invasive endodontic access, ultrasonic-activated chemomechanical preparation, and bioceramic material. A 23-year-old female presented with a 6-month history of thermal sensitivity in tooth 37(lower left second molar), progressing to spontaneous and radiating nocturnal pain. Intraoral examination revealed a supernumerary cusp fused to the mesiobuccal surface of 37 with grayish discoloration at the fusion line. The tooth had positive percussion tenderness but no thermal sensitivity, mobility or periodontal pocketing. Cone-beam computed tomography (CBCT) revealed a fused supernumerary cusp with pulpal communication, a radiolucent area involving the pulp, apical radiolucency, and a distobuccally merged single root canal near the inferior alveolar nerve canal. A customized access cavity was made through the fused cusp to preserve marginal ridge and occlusal surface, followed by chemomechanical preparation using 3% sodium hypochlorite with ultrasonic activation. The canal system was obturated with iRoot SP (Innovative BioCeramix, Canada), activated ultrasonically to eliminate voids. Postoperative radiographs confirmed a compact filling, with minimal extrusion that did not affect the inferior alveolar nerve canal. Three days later, composite resin restoration was applied. Preoperative CBCT imaging, minimally invasive endodontic access and ultrasonic-activated chemomechanical preparationin were crucial in managing this case. iRoot SP demonstrated excellent adaptability to canal irregularities. Care must be taken to avoid overextension into critical anatomical structures. The integration of CBCT diagnostics, ultrasonic disinfection, and bioactive sealers enhances precision endodontics.