A novel rat model of denture stomatitis and the role of antibiotics in the development of the disease.

This study compared different conditions to establish a rat model of denture stomatitis. Immunocompetent Wistar rats were divided into two groups (n = 35): Tetracycline = administration of 0.83 mg/ml of tetracycline hydrochloride 7 days before induction of denture stomatitis and amoxicillin = administration of 0.156 mg/ml of amoxicillin with clavulanic acid 4 days before induction of denture stomatitis. A suspension of Candida albicans was inoculated on the palate followed by the use of a palatal device contaminated with C. albicans inoculum for 4 days to induce denture stomatitis. As controls, some rats were not submitted to any procedure or used a sterile palatal device for 4 days. The development of denture stomatitis was confirmed by visual analysis, colony-forming units per milliliter (CFU/ml) count, histopathological and immunohistochemical analyses, and through myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) assays. Rats were euthanized right after device removal (T0), 4 (T4), or 6 (T6) days after device removal. Tetracycline improved the development of the disease, with more severe clinical signs at T0. Similar results were observed in the CFU/ml count and in the histometric and immunohistochemical analyses. Higher MPO expression was detected in the palates of the tetracycline group (P = .006). Despite the subtle differences between antibiotics, tetracycline showed better results in inducing and maintaining denture stomatitis for at least 4 days after device removal.