The aim of our study was to establish the role of sensory denervation on gingival epithelium proliferation. We investigated the effect of unilateral (right side) and bilateral neurectomy of inferior alveolar nerve on PCNA-positive (PCNA+) cell frequences in the basal layer of gingival epithelium in male Lewis rats. The samples were taken in each group both from left and right side of gingiva, and the PCNA+ cells were counted separately in the epithelium from both sides in all groups. The results of our study indicate that the proliferation of gingival epithelium, expressed as percentage of PCNA+ nuclei of basal layer keratinocytes of gingival squamous epithelium, is better correlated with the trauma than with denervation.