Evaluation of Root Canal Curvature by Different Imaging Method

Objectives: The aim of the present study was to compare the use of X-ray and microcomputed tomography (microCT) imaging to determine the degree of curvature of root canals of the mesial root of mandibular molars.
Methods: For this, 30 mandibular molars were selected. For the radiographic method, the teeth were submitted to an ortho-radial digital radiography. These images were evaluated using ImageJ software regarding the angle of curvature of the root canals and their severity according to the classification proposed by Schneider (1971) and Cabrales et al. (2006). For the microtomographic method, the teeth were scanned in 1176 microCT. In DataViewer software, alignment changes were made until it was possible to visualize the mesial root canal from its orifice to the apical foramen in the longitudinal plane. Then, the images were evaluated in the same way as performed by the radiographic method.
Results: The quantitative results of the angle of curvature showed no statistically significant difference between the methods (p>0.05). The data obtained by the microtomographic method showed excellent reproducibility compared to the radiographic method to determine the angle of curvature (ICC=0.735). For radiographic method, severe curvature was observed in all samples evaluated according to the Schneider classification and only 6.25% according to the classification of Cabrales et al. For microtomographic method, all the samples presented severe curvature according to Schneider and moderate curvature according to Cabrales et al.
Conclusions: From the results obtained in the present study, it can be concluded that the evaluation of the angle of curvature by means of microtomographic images presents excellent reproducibility in relation to the radiographic images which is used as reference standard, which makes possible the use of microCT in the evaluation of curvature severity, with the advantage of to be faster and to make dispensable the radiographic shots during the sample selection.