Detection of periapical lesion development by radiography and computed tomography

Objectives: The aim of this study was to detect the development of experimentally induced periapical lesions using conventional radiography and computed tomography. Methods: The root canals from dogs' teeth were exposed to the oral environment for seven days for contamination, and then sealed for: GI- 7 days, GII- 15 days, GIII- 30 days, and GIV- 60 days. Immediately after each experimental period, radiographs and tomograms were taken in order to detect periapical bone resorption. The periapical radiographs were digitized and bone resorption areas were measured using the VIXWIN 2000 software. The tomograms were assigned scores based on the evolution of periapical bone resorption. The examiners who evaluated the specimens were calibrated and blinded to the groups being evaluated. The radiographic results were analyzed by ANOVA and Tukey's test (α=0.05) and the tomography results were analyzed by Kruskal-Wallis and Dunn's test (α=0.05). Results: The radiographic evaluation did not reveal periapical lesions after 7 days. Lesions could be radiographically observed after 15 and 30 days (47.4% and 77.8% of the cases, respectively) and presented similar dimensions (p>0.05). Lesions were detected in all cases at 60 days, with larger dimensions than those in the previous groups (p<0.05). Tomography evaluation detected lesions at 7 and 15 days (32.5% and 83.3% of the cases, respectively). Lesions were detected in all cases at 30 and 60 days, when the greatest values of bone resorption were observed (p<0.05). Conclusions: Tomography evaluation detected periapical lesion development in its initial stages, even when those lesions were undetectable by radiographic analysis.

MSc scholarship granted by CAPES/Brazil