A STUDY OF THE NEW INHIBITORY DRUG FOR BONE RESORPTION, BISPHOSPHONATES, ON THE ALVEOLAR BONE RESORPTION PROCESS.

双膦酸盐是近年来开发的抑制骨吸收的新药物。为了研究这种药物在牙科领域的可能作用，我们进行了初步的研究，以阐明双磷酸盐对牙槽骨吸收过程的影响。本实验采用低钙日粮诱导骨吸收动物模型，观察组织学变化。30日龄雄性Wistar大鼠，平均体重70 ~ 85 g，试验开始时分别饲喂正常钙饲粮（0.5% Ca, 0.35% P，对照组）和低钙饲粮（0.05% Ca, 0.35% P，低钙组）。各组大鼠再分为两组，每日皮下注射1-羟乙基二烯-1,1-二膦酸酯（HEBP），剂量为4 mg/kg/d，连续6 d。对照组大鼠给予等量生理盐水。第7天处死大鼠，取下颌骨未钙化地面切片。接触x线摄影显示，低钙组与对照组相比，位于磨牙和门牙之间的骨小梁骨被明显吸收。HEBP抑制低钙饮食引起的骨质流失，增加了牙槽骨面积和平均骨宽度。骨的这些变化可能是由于骨矿物质溶解的抑制作用，部分是由于HEBP对骨吸收的抑制作用。本研究结果表明，双膦酸盐将是未来牙科领域防止牙槽骨吸收的一种新型药物。

Bisphosphonates are recently developed new drugs for the inhibition of bone resorption. In order to study the possible role of this drug in the dental field, a preliminary investigation was performed to clarify the effects of bisphosphonates on alveolar bone resorption process. For the experiments, an animal model for bone resorption induced by the low Ca diet was used and the histological changes were observed. Thirty days old male Wistar rats, mean body weight 70-85 g, were fed either normal calcium diet (0.5% Ca, 0.35% P, controls) or low Ca diet (0.05% Ca, 0.35% P, low Ca group) at the beginning of the experiment. These groups of rats were further divided into two groups and received daily by the subcutaneous injection of 1-hydroxyethyliedene-1,1-bisphosphonate (HEBP) at a dose of 4 mg/kg/day for 6 days. Control rats were received the same amounts of physiological saline. The rats were sacrificed at day 7 and undecalcified ground section of mandibular bone was examined. Contact microradiogram showed that trabecular bone located between the molar and incisor tooth were markedly resorbed in the low Ca group compared with the control group. HEBP inhibited the bone loss induced by the low Ca diet and the bone area and the mean bone width of alveolar bone increased. These changes of bone may be due to the inhibitory effects of dissolution of bone mineral and partially due to the inhibitory effects of bone resorption of HEBP. The present result suggests that bisphosphonates will be a novel drug for preventing the alveolar bone resorption in the dental field in future.