COMPARISON BETWEEN PERIAPICAL LESIONS MEASURES BY THE DIFFERENTS PLANS OF THE CONE BEAM COMPUTED TOMOGRAPHY AND THE PERIAPICAL RADIOGRAPH.

Objectives: The aim of this study was to compare linears measures of endodontic lesions by periapical radiograph (PR) and cone beam computed tomography (CBCT), using the long axis of the teeth and upper jaw plan
Methods: Twenty four single root upper teeth with diagnostic of the pulpar necrosis and periapical lesion were selected. Periapical radiographs with film holder were realized for all teeth. After that, CBCT were made in specific locations for each tooth, that confirmed the rupture of cortical bone. For all cases, 2D segmentation measures of periapical lesion were performed to assess the difference between the two forms of analysis of the CBCT in comparison with the periapical radiographs. Depending on the dental arch, the positioning of the coronal and the sagittal slices are alternated due the elliptical shape of the arcade.The best slice plan that represented the region for these measures was used at the CBCT. The DICOM data which every scan were imported and evaluated in the Nemotec^® software. All measures were subjected to statistical analysis One-way ANOVA test and Pearson's correlation analysis.
Results: In the antero-posterior direction, the results showed that there was a good correlation when compared to RP with CBCT using the maxilla plan (r= 0 .832) and tooth long axis (r0 .917). For Supero-inferior direction, the results showed that there was a correlation acceptable both using the maxilla plan (r= 0 .794) as the long axis of the tooth (r0 .798).
Conclusions: When analyzed the image in 3D, teeth with relatively small periapical lesion in PR, may present a larger area of bone destruction when observed in 3 dimensions. Thus, it was possible to conclude that the PR can underestimate the periapical lesions in comparison with CBCT.