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 seven days before induction of denture stomatitis and Amoxicillin = administration of 0.156 mg/mL of amoxicillin with clavulanic acid four 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 four days to induce denture stomatitis. As controls, some rats were not submitted to any procedure or used a sterile palatal device for four days. The development of denture stomatitis was confirmed by visual analysis, CFU/mL count, histopathological and immunohistochemical analyses, and through myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) assays. Rats were euthanized right after device removal (T0), four (T4), or six (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 = 0.006). Despite the subtle differences between antibiotics, tetracycline showed better results in inducing and maintaining denture stomatitis for at least four days after device removal.