Effect of home bleaching and smoking on marginal gingival epithelium proliferation: a histologic study in women

Abstract

BACKGROUND: Animal studies have suggested that home bleaching agents can cause morphological alterations and changes in the proliferative rate of oral epithelium. METHODS: A bleaching agent containing 10% carbamide peroxide with carbopol was used in 11 women (five smokers and six non-smokers) during a 5-week period. Two biopsies were performed, one of them 15 days before the beginning of the home bleaching treatment and the other immediately after the 5-week bleaching treatment. Two analyses were performed in the histological sections obtained from the biopsies: epithelium morphometry and assessment of the epithelium's proliferative activity by proliferating cell nuclear antigen (PCNA) immunohistochemistry. RESULTS: The home bleaching agent increases epithelium thickness and the PCNA index in both smoker and non-smoker patients. CONCLUSION: Carbamide peroxide (10%) caused an augmentation in the proliferative activity within the basal and parabasal layers of the gingival epithelium, resulting in a change in this tissue's morphometry.