种植型弹性牵张器的初步实验研究

目的:探讨利用自主研发的种植型弹性牵张器增高下颌牙槽嵴的可行性。方法:选用6只成年杂种犬,随机分为实验组和对照组,拔除一侧全部前磨牙和第一磨牙。2个月后,每个传送盘内植入两枚自主研发的种植型弹性牵张器行下颌牙槽嵴牵张成骨,传送盘长3 mm,高6 mm。在牵张手术前和术后摄X片,利用X线根管测长的原理测量牵张的高度。分别在牵张完成后4周和10周处死动物,进行组织学研究。结果:下颌牙槽嵴被平均抬高4.7 mm,方向满意。X线显示牵张完成后4周牵张区骨密度增高,10周时新骨密度接近周围骨组织。组织学观察可见牵张区新骨形成良好。结论:具有自加载特性的镍钛形状记忆合金与纯钛部件相结合,为牵张器的开发提供了可尝试的新思路。

Mandibular Distraction Osteogenesis by an Elastic Implant-distraction Apparatus

Objective: To discuss the possibility of augmenting mandibular ridge by distration osteogenesis(DO) using an elastic implant-distraction apparatus.Methods: All the mandibular premolars and first molar were extracted from six adult mongrel dogs.Two months later,box-shaped osteotomies of the alveolar bone were performed out and elastic implant-distraction apparatus were buried in experimental group.The radiographs were taken before and after the operation.The bone height was measured by the principal of measuring the length of root canal on radiographs.The animals were killed at 4 or 10 weeks after distraction and examined histologically.Results: The bone segments were average lifted up 4.7mm.4 weeks after distraction,the radiographs showed that there was regeneration of bone in distraction gaps.The new bone and the normal bone could not be differentiated clearly 10 weeks after distraction.Histological sections showed that there was new bone formed in distraction gaps.Conclusion: It is a new tentative approach to develop distracter by TiNi shape memory alloy assembled with pure titanium apparatus.