Aim: The purpose of this study was to investigate the expression of cyclooxygenase-2 (COX-2) in radicular cysts. Methodology: Thirty biopsy specimens of radicular cysts were examined using immunohistochemistry. A peroxidase-labelled streptavidin-biotin technique was used for identification of the COX-2. Fisher's exact test (two-tail) was used for statistical analysis of the results. Results: The result demonstrated that COX-2 expression was significantly higher in radicular cysts with higher levels of inflammatory infiltrates. COX-2 stain was detected in the lining epithelium, subepithelial fibroblasts, macrophages and endothelial cells in all specimens. Conclusions: COX-2 expression is significantly higher in radicular cysts. COX-2 may play an important role in the pathogenesis of radicular cysts.
