目的:分析回收的正畸小窝的形态变化,并评估可能对小窝的重新定位产生不利影响的机械性能。
方法:根据尖端的形态变形程度,用扫描电子显微镜对检索到的小船进行分类。为了评估重新插入过程中机械特性的差异,插入扭矩的变化,在未使用的对照和检索到的小序列之间比较了插入时间和成功插入负荷的差异.此外,使用能量色散x射线光谱法对回收的微流进行表面成分分析。
结果:在大多数(>84.5%)的回收小体中,明显的尖端变形。诸如插入位点或插入持续时间的初始条件与尖端变形的存在无关。成功骨穿透的插入载荷与尖端变形程度成比例增加;然而,插入扭矩的连续变化与控制相似。沉积的碎片,如碳,钙,磷在取回的小船上被注意到。
结论:初次插入后取回的Miniscrews由于尖端结构的变形而表现出降低的切割能力,以及表面污染。
OBJECTIVE: To analyze morphological variations of retrieved orthodontic miniscrews and to evaluate the mechanical properties that may adversely affect
relocation of miniscrews.
METHODS: Retrieved miniscrews were classified with scanning electron microscopy according to the degree of morphological deformation of the tip. To evaluate the differences in mechanical characteristics during reinsertion, changes in insertion torque, insertion time and differences in successful insertion load were compared between unused controls and retrieved miniscrews. In addition, surface composition analysis of retrieved miniscrews was performed using energy-dispersive x-ray spectroscopy.
RESULTS: Significant tip deformation was evident in the majority (>84.5%) of retrieved miniscrews. Initial conditions such as insertion site or duration of insertion were not associated with the presence of tip deformation. Insertion load for successful bone penetration increased in proportion to the degree of tip deformation; however, serial changes in insertion torque were similar to those of the controls. Deposited debris such as carbon, calcium, and phosphorus was noted on the retrieved miniscrews.
CONCLUSIONS: Miniscrews retrieved after primary insertion exhibited decreased cutting ability due to deformation of the tip structure, as well as surface contamination.