Introduction: Alveolar bone destruction is associated with enhanced osteoclast activity; tumor necrosis factor receptor-associated factor 6 (TRAF6) is suggested to contribute to the differentiation of osteoclasts. The purpose of this study was to observe the immunohistochemical localization of TRAF6 and bone resorption in induced periapical lesions in rats.
Methods: Periapical lesions were induced by an occlusal pulp exposure in the mandibular first molars. Animals were randomly killed at 0, 7, 14, 21, and 28 days. Frontal sections were prepared for immunohistochemistry and enzyme histochemistry.
Results: A few TRAF6-positive cells and osteoclasts could be observed on day 7. Both climaxed on day 14. In the 21-day and 28-day samples, TRAF6 expression decreased, and fewer osteoclasts were observed. From day 7 to day 28, a significant positive correlation was found between TRAF6 expression and osteoclast numbers.
Conclusions: These findings showed that TRAF6 might be associated with osteoclast differentiation in periapical lesions.