Effect of a new bisphosphonate, YM175, on experimental periodontitis in hamsters

Abstract

A new bisphosphonate, disodium dihydrogen (cycloheptylamino) methylene-1, 1-bisphosphonate (YM175) i s a potent inhibitor of bone resorption. The purpose of this study was to evaluate the effect of bisphosphonates, including YM175, on alveolar bone loss in experimental periodo ntitis using Golden hamsters. Hamsters were fed powdered high-carbohydrate diet (30% sucrose) to induce periodontal disease, andr eceived subcutaneous injections of either saline, YM175 (0.001-0.3mg/kg) or 1-hydroxyethylidene-1, 1-bisphosph onate (HEBP, 1-10mg/kg), which has been previously shown to regulate bone metabolism. Thef ollowing results were obtained: 1. In the control group (saline), the number of osteoclasts on the mesial side of the alveolar bone of the lower first molar was increased on the s econd week of the experiment.H owever, in the experimental group that was administered YM175, the number of osteoblasts on the distal side of the alveolar bone was increased on the first week, and no increase in the number of osteoclasts was observed, even on the second week. 2. Alveolar bone loss at the lower first molar, decreased with the consecutive administration of bisphosphonates. 3. The inhibitory effect of HEBP on alveolar bone loss was weaker than that of YM175. 4. Weight loss of mandibular bone was inhibited by the ad ministration ofYM175. 5. The levels of plasma calcium, inorganic phosphate and alkaline phosphatase were not affected b ythe administration of YM175.
In conclusion, YM175 significantly inhibited alveolar bone resorption in experimental periodontitis, andmay, therefore, offer a new approach to the treatment of periodontal disease.