RESUMO
OBJECTIVE: To investigate the effect of sildenafil citrate on the prevention and progression of experimental periodontitis (EP) in rats. MATERIALS AND METHODS: Thirty-six male Wistar rats were randomly assigned into two groups: Group 1 (preventive) and Group 2 (progression). In Group 1, the animals received daily doses of sildenafil (10 mg/kg) or vehicle for 30 days, and EP was induced on the 15th day. In Group 2, the EP was induced on the first day, and the animals received daily doses of sildenafil (10 mg/kg) or vehicle from the 15th day. For EP, ligatures were placed around the right first mandibular molars. Microtomographic, histomorphometric and histological analyses were carried out to evaluate the alveolar bone loss and inflammatory degree. For statistical analyses, t test and the Mann-Whitney test were used, considering a level of significance of 95%. RESULTS: In Group 2, the animals treated with sildenafil showed a significantly lower bone resorption (p = .05). Similarly, the subgroup treated with sildenafil displayed a significantly lesser degree of inflammation (p = .01). No significant differences were observed between the subgroups of the Group 1. CONCLUSIONS: Sildenafil decreased the inflammatory process, as well as the alveolar bone loss when used to modulate the progression of experimental periodontitis.