Bisphosphonate inhibits alveolar bone resorption in experimentally-inducedperi-implantitis in dogs

The purpose of this study was to determine the effect of bisphosphonate on alveolar bone resorption in experimentally-induced peri-implantitis in beag le dogs. Experimental peri-implantitis was induced by ligation around the a butments, 6 months after placement of a fixture. Pamidronate (0.6 mg/kg) wa s injected intramuscularly every 3 days into each of 5 dogs. Another 5 dogs served as the control group and were injected with saline only. Peripheral blood and urine samples were collected every week up to 12 weeks after pla cement of the ligature. Standard X-rays were taken every week. Urinary deox ypyridinoline (DPD) and serum osteocalcin (OC) were evaluated by ELISA as m arkers of alveolar bone remodeling. X-ray films were analyzed with a comput er image analyzer. After 12 weeks, the bone level was measured after remova l of the gingival flap. The distance between the top surface of the fixture and the fundus of the defect was significantly lower in the Pamidronate gr oup (1.59+/-0.55 mm, mean+/-SD) than in the control group (2.41+/-0.48 mm). Bone density analyzed from the X-ray films was significantly higher in the bisphosphonate group (69.2+/-8.7%, mean+/-SD) than in the control group (5 0.3+/-12.8%) after 2 to 8 weeks compared with the baseline value (100%). OC and DPD levels fluctuated during the experimental period. These findings s uggest that bisphosphonate inhibits the progression of alveolar bone resorp tion during ligature-induced peri-implantitis in dogs.