Microcomputed tomography analysis of the root canal morphology of single-rooted mandibular canines

To investigate the anatomy of single-rooted mandibular canine teeth using microcomputed tomography (μCT).

One hundred straight single-rooted human mandibular canines were selected from a pool of extracted teeth and evaluated using μCT. The anatomy of each tooth (length of the roots, presence of accessory canals and apical deltas, position and major diameter of the apical foramen and distance between anatomical landmarks) as well as the two- and three-dimensional morphological aspects of the canal (area, perimeter, form factor, roundness, major and minor diameter, volume, surface area and structure model index) were evaluated. The results of the morphological analysis in each canal third were compared statistically using Friedman's test (α = 0.05).

The length of the roots ranged from 12.53 to 18.08 mm. Thirty-one specimens had no accessory canals. The location of the apical foramen varied considerably. The mean distance from the root apex to the major apical foramen was 0.27 ± 0.25 mm, and the major diameter of the major apical foramen ranged from 0.16 to 0.72 mm. Mean major and minor diameters of the canal 1 mm short of the foramen were 0.43 and 0.31 mm, respectively. Overall, the mean area, perimeter, form factor, roundness, major and minor diameters, volume, surface area and structure model index (SMI) were 0.85 ± 0.31 mm(2) , 3.69 ± 0.88 mm, 0.70 ± 0.09, 0.59 ± 0.11, 1.36 ± 0.36 mm and 0.72 ± 0.14 mm, 13.33 ± 4.98 mm(3) , 63.5 ± 16.4 mm(2) and 3.35 ± 0.64, respectively, with significant statistical difference between thirds (P < 0.05).

The anatomy and morphology of the root canal of single-rooted canines varied widely in different levels of the root.