Igarashi K, Adachi H, Mitani H, Shinoda H
Department of Orthodontics, School of Dentistry, Tohoku University, Sendai, Japan.
J Dent Res. 1996 Sep;75(9):1644-9. doi: 10.1177/00220345960750090501.
Root resorption associated with tooth movement is an unsolved problem in orthodontics. If such root resorption could be prevented, it would be an important contribution toward reducing risk factors in orthodontic treatment. The purpose of this study was to examine the effects of the topical administration of a bisphosphonate, risedronate, which is known to be a potent blocker of bone resorption, on root resorption during tooth movement and on the repair of the resorbed root surface after tooth movement in rats. In the first experiment, both the right and left upper first molars were moved buccally with a standardized expansion spring under administration of risedronate. After day 7, extensive root resorption had occurred on the control side, and the area of root resorption reached a maximum on day 14. The topical administration of risedronate caused a significant and dose-dependent inhibition of root resorption after the orthodontic force was applied. In the second experiment, the right and left upper molars were first moved buccally for 3 weeks. Risedronate treatment began on the day the spring was removed. After the force was withdrawn, the resorbed root surfaces on both the control and risedronate-treated sides were gradually restored by apposition of repair cementum (cementoid). The topical administration of risedronate did not appear to inhibit the repair process of root resorption. These results suggest that the topical administration of risedronate may be useful in preventing root resorption of teeth during orthodontic treatment.
与牙齿移动相关的牙根吸收是正畸学中一个尚未解决的问题。如果能够预防这种牙根吸收，将对降低正畸治疗中的风险因素做出重要贡献。本研究的目的是研究局部应用双膦酸盐利塞膦酸钠（已知是一种有效的骨吸收阻滞剂）对大鼠牙齿移动过程中牙根吸收以及牙齿移动后吸收牙根表面修复的影响。在第一个实验中，在给予利塞膦酸钠的情况下，用标准化的扩弓弹簧将左右上颌第一磨牙颊向移动。7天后，对照侧出现广泛的牙根吸收，牙根吸收面积在第14天达到最大。正畸力施加后，局部应用利塞膦酸钠对牙根吸收产生了显著的剂量依赖性抑制作用。在第二个实验中，首先将左右上颌磨牙颊向移动3周。在拆除弹簧当天开始给予利塞膦酸钠治疗。撤去力后，对照侧和利塞膦酸钠治疗侧吸收的牙根表面通过修复牙骨质（类牙骨质）的沉积逐渐恢复。局部应用利塞膦酸钠似乎并未抑制牙根吸收的修复过程。这些结果表明，局部应用利塞膦酸钠可能有助于预防正畸治疗期间牙齿的牙根吸收。
