Endodontic Management Of C-Shaped Mandibular And Curved Maxillary Premolars

This case demonstrates a successful endodontic management of tooth 34 with a C-shaped configuration and tooth 15 with a curved root canal, suggesting that premolars have complex anatomy. A 36-year-old male presented with discoloration of bilateral posterior teeth. Clinical examination: Tooth 34: Buccal caries extending to the pulp, positive probing pain, percussion (±), thermal test (delay), mobility (normal). Tooth 15: Distal proximal caries approaching the pulp, positive probing pain, percussion (±), thermal test (sensitivity), mobility (normal). CBCT findings: Tooth 34: Coronal low-density area reaching the pulp chamber, C-shaped root apex, and apical third canal calcification. Tooth 15: Coronal low-density area near the pulp, no apical radiolucency. Diagnosis: Pulpitis (Teeth 15, 34). Treatment: Tooth 34: Microscope-assisted root canal therapy identified two canals (mesial and distal). Root canals were cleaned, shaped, and obturated with iRoot SP (Innovative BioCeramix Inc) and gutta-perchas, resin restoration. Tooth 15 exhibited a severely curved canal (Schneider’s α=45°) with a moderate curvature radius (r=3.5 mm, per Pruett et al.), obturation with iRoot SP and CAD/CAM restoration. Three-month follow-up, both teeth were asymptomatic, clinical and radiographic prognosis favorable. Microscopic visualization and radiographic analysis confirmed the presence of a C-shaped canal configuration. C-shaped roots occur in 24%–45% of mandibular first premolars. Root curvature increases risks of canal transportation and instrument separation. The angulated preoperative radiograph image and precise tactile examination of all canal walls can detect anatomical variations in premolar canals.