Abstract
A new bisphosphonate, disodium dihydrogen (cycloheptylamino) -methylene-1, 1-bisphosphonate (cimadronate, YM175) inhibits alveolar bone loss in experimental periodontitis in hamsters. The purpose effects of cimadronate on the morphology and the function of osteoclasts were examined. Hamsters were fed a powdered high-carbohydrate diet, and ligated with silk sutures at the lower first molar (M1) to induce periodontitis. The alveolar bone loss was estimated by measurement of the area between the cementoenamel junction and the crest of alveolar bone at the M1 by radiograph. Animals were administered cimadronate subcutaneously at the dose of 0 (control), 0.03, 0.1 and 0.3mg/kg×2times/week. The amount of the alveolar bone loss in the above groups (at the 4th week) was, 1.05±0.31, 0.95±0.25, 0.59±0.14 and 0.68±0.14 mmmm2, respectively. The number of osteoclasts 3-fold was higher in the 0.1 and 0.3mg/kg cimadronate administered groups (p<0.01), than the control at the 4th day after the ligation with silk suure. Electronmicroscopic examinations, of the osteoclasts revealed the deficiency in ruffled border formation in the cimadronateadministered groups. These findings suggest that cimadronate affects the function of osteoclasts.
In conclusion, the inhibition of alveolar bone loss by cimadromate might be due to the dysfunction of osteoclasts, although they increased in number.
