Pharmacological retention with Bisphosphonate after intrusion of molars using orthodontic implants

本研究的目的是探讨局部使用双膦酸盐对磨牙内嵌后复发运动的影响。以20周龄雄性apague - dawle （SO）大鼠为实验动物。双侧上颌磨牙内嵌镍钛封闭螺旋弹簧，用钛螺钉固定于上颌皮质骨。根据保留方法的不同，将实验动物分为不同的组；即组1侵入后不设固位器，组2为板式固位器。第1组在入侵开始14天后取出线圈。侵入后2周，每2天在右磨牙区骨膜下注射30μ ml双膦酸盐（Cl2MBP 20mMol）。左第一磨牙作为对照，注射0.9% Nacl溶液。另一方面，在第2组的每只动物中，与第1组相同的时间停止侵入力，因此，更多的咬板式保持器给予2周。留置后，以与第一组相同的方式局部给药双膦酸盐。两组分别在第0天、第14天、第28天、第42天分别对上颌牙列进行精确印模。然后制作上颌牙列的石头模型，沿磨牙矢状修剪。为了评估牙齿的运动，所有的石模型都精确地在上颌磨牙中矢状面切割。在这个平面上测量磨牙的侵入量。作为这项研究的结果。1组和2组的平均侵入量基本相同（0.35 mm±0.06）。组1和组2嵌套磨牙复发率分别为88%和83%，两组间无统计学差异。综上所述，虽然有文献报道了双膦酸盐对水平平面移动牙复发的预防作用，但局部应用双膦酸盐Less对防止嵌套磨牙复发可能并不有效

The purpose of this study was to investigate the effects of the topical administration of a bisphosphonete on rlapse movement after intsion of the molars. Male Aprague-Dawle (SO) rats of 20 weeks-old were used as expeimental animals. Bilateral maxillary molars were intruded with NiTi closed coil springs those were placed at the maxillary cortical bone with titanium screws. Experimental animals were divided into groups depending on the difference of retention methods; namely Group 1 had no retainer after intrusion and Group 2 was given plate type of retainer. In he Group 1, coil sings were removed after 14 days since intrusion began. then 30μ ml of bisphosphonate (Cl2MBP 20mMol) was injeded beneath the subperiosteum at the right molar area every 2 days during 2 weeks after intrusion. The left first molar served as a control with an injection of 0.9% Nacl solution. On the other hand, in each animal of Group 2, the intrusive force was discontinued at the same timing of Group 1 and thereaf … More ter biteplate type retainer was given for 2 weeks. After retention, the topical administration of a bisphosphonate was applied in the same manner as in Group 1. In the both groups, the precise impression of the maxillary dentition was taken at 0-day, 14-day, 28-day, and in addition at 42-day in Group 2 only. Then a stone model of the maxillary dentition was made and sagittally trimmed along the molars. To evaluate of tooth movement, all stone models were precisely cut at the midsagittal plane of the upper molars. The amount of intrusion of the molars was measured on that plane. As the result of this study. the average amount of intrusion in Group 1 and Group 2 was almost same (0.35 mm±0.06). The relapse rates of intruded molars in Group 1 and Group 2 were 88% and 83% respectively and there was also no statistical difference between those two groupsIn conclusion, although the effects of bisphosphonate to prevent relapse of moved teeth in the horizontal plane have been reported, it may not be useful to prevent relapse of intruded molars wlth the topical adiministration of a bisphosphonate Less