Retreatment of a Tooth With Calcified Canals Using Cold Ceramic: A Case Report.

Root canal treatment (RCT) has high success rates; however, failures may occur when chemo-mechanical preparation or obturation are inadequate, leading to persistent infection and periapical lesions. Calcification of the root canal system may obstruct effective canal negotiation and preparation, increasing the risk of under-debridement and treatment failure. When calcified canals cannot be fully managed, the prognosis is typically poor, necessitating extraction or apical surgery. This case report presents nonsurgical retreatment of a symptomatic mandibular left first molar with partially calcified canals. Despite careful negotiation, apical patency could not be safely achieved. Chemo-mechanical debridement with copious irrigations was performed, and the canals were obturated with cold ceramic (CC), a hydraulic calcium silicate-based cement, to establish a corono-apical seal. Symptoms resolved, and radiographs showed near-complete periapical healing maintained at four years. Within the limits of a single case, the favorable outcome is most likely to reflect effective disinfection combined with a secure seal. CC was selected for its biocompatibility, alkaline pH-associated antibacterial effect, and sealing capacity, and it may serve as a pragmatic obturation alternative to gutta-percha when full-length instrumentation is not feasible. A conservative, tooth-preserving approach can be appropriate in similar calcified cases. Further studies are needed to explore CC's potential and long-term outcomes.