Fluoxetine reduces periodontal disease progression in a conditioned fear stress model in rats

Background and Objective: Recent evidence suggests that the use of fluoxetine could reduce periodontal disease severity. However, the effect of fluoxetine on periodontal disease has not been tested in the context of conditioned fear stress (CFS). We hypothesized that inhibition of chronic stress by fluoxetine might decrease the levels of bone loss in periodontal disease. The aim of the present study was to analyze the effect of fluoxetine on bone loss in chronic periodontitis. Material and Methods: Fourteen Wistar rats were submitted to ligature-induced periodontal disease and divided into four groups (A-D). Groups A (n = 3) and B (n = 4) were not stressed, while Groups C (n = 3) and D (n = 4) were submitted to a CFS paradigm for 38 d. Daily fluoxetine (20 mg/kg) was administered to Groups B and D from day 20 to day 39, at which point the rats were submitted to an open field test and killed on day 40. Mandibles were removed for histological and immunohistochemical analyses. Results: Stress was associated with a higher level of bone loss in Group C compared with Group A. Additionally, no differences in bone loss were observed among Groups A, B and D. Conclusion: We showed that stress is associated with the progression of bone loss in a CFS model in rats and that fluoxetine treatment reduces the bone loss.