Microscopic Retreatment Of Mandibular Molar With C-Shaped Canal Configuration

C-shaped root canals predominantly occur in the mandibular second permanent molars, characterized by their C-shaped cross-sectional anatomy. The complex root canal system increases the risk of incomplete debridement and inadequate obturation. This case report presents the microscope-assisted retreatment of a mandibular second molar with a C-shaped canal configuration. A 27-year-old female patient presented to our hospital due to discomfort in the bite of the posterior teeth for several days. The affected tooth had previously undergone root canal treatment (RCT) and full-coverage restoration at an external clinic. Clinical and radiographic examination revealed underfilled canals in tooth #47. Under dental operating microscope (DOM), the pre-existing obturation material was removed, and the working length was re-determined. The canals were prepared according to four identified canal orifices, followed by root canal obturation using iRoot SP bioceramic sealer in combination with warm vertical compaction . The C-shaped canal has complex anatomical morphology, including intercanal communication branches and root canal curvature. Ni-Ti with good flexibility should be used to prepare the root canal to prevent incomplete preparation and missing root canal during root canal treatment. The mandibular second molar has a high prevalence of C-shaped canals, often presenting with tortuous and concealed configurations, posing significant clinical challenges. Conscious exploration and microscopic visualization enhance the detection rate and treatment success of C-shaped canal systems.