Development of the periapical lesion: radiographic and histological analysis

Objectives: To compare the radiographic and histological aspects of periapical lesion development. Methods: The root canals from dogs' teeth were exposed to oral environment for seven days for contamination, then sealed for: GI- 7 days, GII- 15 days, GIII- 30 days, and GIV- 60 days. Immediately after the experimental periods, radiographs were taken to detect periapical lesion. The periapical radiographs were digitized and bone resorption areas were measured using the VIXWIN 2000 software. Also, it was obtained histological sections of the periapical region, stained with Hematoxilin and Eosin. The histological periapical osseous resorption area was measured using the software Image ProPlus. The examiners who evaluated the specimens were calibrated and blinded to the groups being evaluated. The radiographic and histological results were analyzed by ANOVA and Tukey test (p<0.05). The Wilcoxon and Pearson tests were also used for comparison and correlation analysis of radiographic and histological results. Results: The radiographic evaluation did not reveal periapical lesions at seven days. Lesions could be radiographically observed after 15 and 30 days, without significant difference (p>0.05). Lesions were detected in all cases at 60 days, with larger dimensions than those in the previous groups (p<0.05). It was possible to measure areas of histological osseus resorption after the period of 7 days. Major dimension of osseus resorption area was observed after 30 and 60 days (p<0.05). The Wilcoxon test showed difference between the used methods after 30 days, with major histological than radiographic areas. The Pearson test showed no correlation between the radiographic and histological results after the evaluated periods. Conclusion: The osseus resorption area is better observed by histological than radiographical analysis at the initial periods of the periapical lesion development. The methods are similar at the final stages, when the periapical lesion is radiographically visible.

Financial Support: Fapesp (05/04599-8), CNPq (151072/2005)