Abstract Aim. The purpose of this study was to investigate the scanning and segmentation precision of surface models of molars for the detection of small volumes, such as the reduced pulp cavity; formation of mineral deposits; detection of narrow root canals and to improve the clinical and morphological understanding of the number of root canals and their configuration. Methods. Eighteen human molars were scanned using X-ray micro-computed tomography. The reconstruction of the surface models had a precision of