Three-dimensional modelling and concurrent measurements of root anatomy in mandibular first molar mesial roots using micro-computed tomography.

Abstract

To obtain concurrent radicular measurements in the mesiobuccal (MB) and mesiolingual (ML) canals of mandibular first molars using scanned data of micro-computed tomography (μCT) with novel software. The scanned data from 37 mandibular first molar mesial roots were reconstructed and analysed with custom-developed software (Kappa2). For each canal, three-dimensional (3D) surface models were re-sliced at 0.1-mm intervals perpendicular to the central axis. Dentine thicknesses, canal widths and 3D curvatures were measured automatically on each slice. Measurements were analysed statistically with anova for differences at each direction and at different levels of both canals. Lateral dentine thicknesses were significantly higher than mesial and distal thicknesses, at all the levels of both canals (P<0.001). Mesial thicknesses were significantly higher than distal thicknesses in the coronal third of both canals (P<0.001). Thinnest dentine thicknesses were mainly located on the disto-inside of both canals. Narrowest canal widths were 0.24±0.10 and 0.22±0.09mm in MB and ML canals, respectively. Canal curvatures were greatest in the apical third of both canals (P<0.001), and they were greater in the MB canals than in the ML canals (P<0.05). Micro-computed tomography with novel software provided valuable anatomical information for optimizing instrumentation and minimizing mishaps in nonsurgical root canal treatment.