Effects of Tacrolimus and Nifedipine, Alone or in Combination, on Gingival Tissues

Background: The aim of this study is to compare gingival changes induced by short‐ and long‐term tacrolimus and nifedipine administration, alone or in combination, and evaluate the expression levels of tumor suppressor phosphatase and tensin homolog (PTEN) in drug‐induced gingival overgrowth. Methods: Eighty rats were equally divided into eight groups: 1) tacrolimus for 8 weeks; 2) nifedipine for 8 weeks; 3) tacrolimus and nifedipine for 8 weeks; 4) 8‐week control; 5) tacrolimus for 24 weeks; 6) nifedipine for 24 weeks; 7) tacrolimus and nifedipine for 24 weeks; and 8) 24‐week control. Histomorphometric analyses included measurements of epithelial thickness, connective tissue thickness, and height. Stereologic analyses included measurements of volumetric densities of fibroblasts (Vf), collagen fibers (Vcf), and blood vessels (Vbv). In addition, PTEN expression was analyzed using immunohistochemistry. Results: Epithelial thickness and connective tissue thickness were significantly increased in groups 5, 6, and 7 compared to group 8 (P