Effects of Risedronate on Alveolar Bone Loss and Angiogenesis: A Stereologic Study in Rats

Background: The present study was designed to evaluate the effects of risedronate, one of the most potent bisphosphonates, on alveolar bone resorption and angiogenesis in rats with experimental periodontitis to identify dose-response curves and treatment durations that can be therapeutic for periodontal therapy versus those associated with osteonecrosis of the jaws.Methods: Thirty-five rats, 25 with experimental periodontitis (groups 1 through 5) and 10 with healthy periodontium (groups 6 and 7), were divided into seven equal groups: group 1 received no treatment; groups 2 and 3 received risedronate, 0.1 and 1 mg/kg, respectively, for 3 weeks; groups 4 and 5 received risedronate, 0.1 and 1 mg/kg, respectively, for 8 weeks; and groups 6 and 7 received 0.9% NaCl for 3 and 8 weeks, respectively. Animals in groups 2 through 7 were administered treatment 5 days per week. After histologic processing, histomorphometric and stereologic analyses were carried out to estimate the number of blood vessels (NBV) and th...