钛合金微型种植支抗即刻负重及离子释放的研究  

Titanium alloy mini-implants for orthodontic anchorage: Immediate loading and metal ion release

作　　者：许胜 柳忠豪 徐欣[2] 

机构地区：[1]烟台市口腔医院 [2]山东大学口腔医院

出　　处：《中国口腔种植学杂志》2011年第1期83-83,共1页Chinese Journal of Oral Implantology

摘　　要：纯钛种植支抗在正畸中已经被广泛应用。种植支抗的早期负重十分重要,他可以缩短正畸时间,但是相对也会增加支抗脱落的风险,因为此时骨整合尚不完善。钛合金由于具有更好的强度,被用来替代纯钛作为支抗材料。然而,由于钛合金材料的抗腐蚀性低,会存在金属离子的释放。本研究的目的是观察愈合阶段种植支抗即刻负重对骨结合强度的影响及钒离子的释放量。将钛合金种植支抗植入兔的胫骨内,第1、4、12周时分别做拔出力测试。在第1周和第4周时,负重与无负重相比较,拔出力没有明显的差异。第12周时,无负重组较负重组有更大的拔出力,差异明显。将兔子的肾脏、肝脏及肺脏切除,用分光光度计测原子吸光值。与空白对照组相比,1周后钒的量轻度增加,4周后明显增加,12周后钒的量较前有所降低,比1周后的值还要低。各个时间点钒的浓度值都没有达到动物模型的毒性值范围。应力分析显示钛合金及商业纯钛种植支抗都能满足临床上的力矩值。结果说明钛合金种植支抗可以用于正畸中早期负重的病例。Removable osseointegrated titanium mini-implants were successfully used as anchorage devices in orthodontics.The early load is necessary to simplify the mini-implant methodology,but can lead to failure during osseointegration.The Ti–6Al–4V alloy was used instead of commercially pure Ti due to its superior strength.However,the corrosion resistance is low,allowing for metal ion release.The purpose of this work was to analyze the immediately loaded mini-implant fixation and to gauge the vanadium ion release during the healing process.Titanium alloy mini-implants were inserted in the tibiae of rabbits.After 1,4 and 12 weeks,they were submitted to removal torque testing.There was no increase in the removal torque value between 1 and 4 weeks of healing,regardless of the load.Nevertheless,after 12 weeks,a significant improvement was observed in both groups,with the highest removal torque value for the unloaded group.The kidney,liver and lung were also extracted and analyzed by atomic absorption spectrometry.In comparison with the control values,the content of vanadium increased slightly after 1 week,significantly increased after 4 weeks and decreased slightly after 12 weeks,without reaching the 1 week values.A stress analysis was carried out which enables both the prediction of the torque at which commercially pure（CP） Ti and Ti–6Al–4V deform plastically and the shear strength of the interface.This analysis reveals that the removal torques for CP Ti dangerously approach the yield stress.The results of this rabbit model study indicate that titanium alloy mini-implants can be loaded immediately with no compromise in their stability.The detected concentration of vanadium did not reach toxic levels in the animal model.

关 键 词：钛合金材料 种植支抗 即刻负重 离子释放 骨结合强度 微型 商业纯钛 早期负重 

分 类 号：R783.5[医药卫生—口腔医学]