Pharmacological retention with Bisphosphonate after intrusion of molars using orthodontic implants

本研究的目的是探讨双膦酸盐局部给药对磨牙内缩后下垂运动的影响。实验动物为20周龄雄性Aprague-Dawle（SO）大鼠。将镍钛闭合螺旋弹簧用钛螺钉固定在上颌皮质骨上，压入双侧上颌磨牙。根据固位方式的不同将实验动物分组，即1组压入后不放置固位体，2组给予平板式固位体。在第1组中，自侵入开始14天后取出弹簧圈。然后在2周内每隔2天在右侧磨牙区骨膜下注射30μ ml双磷酸盐（Cl_2MBP20mMol）。左侧第一磨牙作为对照，注射0.9%NaCl溶液。另一方面，在第2组的每只动物中，在与第1组相同的时间停止侵入力，并随后 ...更多信息 术后2周，用咬板式固位体固定。保留后，以与第1组相同的方式局部给予双膦酸盐。在两组中，在0天、14天、28天以及仅在第2组中的42天获取上颌牙列的精确印模。然后制作上颌牙列的石制模型，并沿臼齿沿着向矢状修剪。为了评估牙齿移动，所有结石模型都在上磨牙的正中矢状面精确切割。在该平面上测量磨牙的侵入量。作为这项研究的结果。第1组和第2组的平均侵入量几乎相同（0.35 mm±0.06 mm）。第1组和第2组的复发率分别为88%和83%，两组之间也无统计学差异。总之，尽管双膦酸盐在水平面上预防移动牙复发的效果已被报道，但局部施用双膦酸盐对预防侵入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