Immunohistochemical Detection of Factors Related to Cellular Proliferation and Apoptosis in Radicular and Dentigerous Cysts

Introduction: This study proposed to investigate aspects of cell proliferation and death in the epithelium of radicular (RCs) and dentigerous (DCs) cysts. Methods: Serial sections of 17 RCs and 9 DCs were prepared for immunohistochemical detection of caspase-3, BcI-2, and Ki-67 antigens. Results: Caspase-3 was detected mainly in the suprabasal and superficial epithelial cells of RCs and DCs, whereas Ki-67 was detected predominantly in the basal layer. Both markers had significant expression in hyperplastic epithelium related to an intense inflammation in the capsule. Immunoreactivity for BcI-2 was restricted to the basal layer and was significantly higher in atrophic epithelium of DCs than that of RCs. Conclusions: These results suggest that epithelial proliferation is balanced by apoptosis and that the presence of inflammation inhibits the BcI-2 expression. DCs and RCs have different formation mechanisms but have similar biological behavior in the presence of intense inflammatory infiltrate. (J Endod 2011;37:36-39)