Investigating the Effects of Systemically Administered Strontium Ranelate on Alveolar Bone Loss Histomorphometrically and Histopathologically on Experimental Periodontitis in Rats

Background: The aim of this study is to investigate effects of strontium ranelate (SR) on alveolar bone loss (ABL) in rats with experimental periodontitis. Methods: Forty Wistar rats were randomly divided into five groups: 1) control (n = 8); 2) ligated (n = 8); 3) 300 mg/kg SR (SR300, n = 8); 4) 625 mg/kg SR (SR625, n = 8); and 5) 900 mg/kg SR (SR900, n = 8). To create experimental periodontitis, 4/0 silk ligatures were inserted submarginally around first molars at the right mandible. After 11 days, rats were sacrificed. ABL was calculated by measuring cemento-enamel junction and alveolar crest distance. Interleukin (IL)-1 beta, osteoprotegerin (OPG), and bone-specific alkaline phosphatase (BALP) serum levels were determined by enzyme-linked immunosorbent assay. Histopathologic analysis was used to evaluate inflammatory cell infiltration, numbers of osteoblasts and osteoclasts, and receptor activator of nuclear factor-kappa B ligand (RANKL) activity. Results: ABL was significantly lower in SR900 group than in the ligated group (P <0.05). Osteoclast numbers in ligated group were significantly higher than in the control, SR300, and SR900 groups (P < 0.05). In ligated, SR625, and SR900 groups, significantly higher osteoblast numbers were detected than in control group (P < 0.05). Osteoblast numbers in SR625 group were significantly higher than in the SR300 group (P <0.05). RANKL activities in SR900 and control groups were close to each other (P >0.05). Serum IL- 1 beta, OPG, and BALP levels revealed no significant difference (P >0.05). Conclusion: It can be concluded that SR can reduce RANKL activity and osteoclast numbers, as well as ABL.