Microcomputed tomography evaluation of the root canals morphology of the mandibular first molars.

OBJECTIVE The knowledge of the internal anatomy of the root canal system and its variations has a significant impact on the quality and outcome of endodontic treatment. The aim of this study was to evaluate the three-dimensional anatomical features of the root canals of mandibular first molars by using micro-computed tomography. MATERIAL AND METHODS Sixty mandibular first molars were scanned using a high-resolution micro-computed tomography device. The 2- and 3-3-dimensional anatomical features of each root such as distance between anatomical apex and apical foramen, the number of the lateral canals and configuration of the isthmuses, were evaluated. RESULTS The average distance between the anatomical apex and the apical foramen was 1.047 mm. Lateral canals were present in 85% of the cases, while 76% of them were localized in the apical third of the root. 80% of the mesial roots had isthmuses and the configuration of Type I, according to the Fan classification, was the most prevalent (35%). CONCLUSION The results of this study revealed the wide variations of internal root canal anatomy in mandibular first molars, including lateral canals and isthmuses. A clinician should always consider the possible difficulties of anatomical variations before starting root canal treatment, to select the best and optimal treatment strategies.