微种植体支抗即刻和早期加载的电镜观察

Scanning electron microscopic observation of immediate and early loading of mini-screw implants

目的研究不同加载时间及加载力值对微钛螺纹钉种植体-骨结合界面的影响。方法选取5只Beagle犬建立实验动物模型,分别在左、右两侧上颌牙槽骨内植入微钛螺纹钉种植体各9枚。采用恒定力值为100 g及300 g的镍钛螺旋拉簧,分别在即刻、第2、4、8周对两侧种植体加载,对照组不加力。于第20周处死动物,取含微钛螺纹钉及其周围2 mm组织块,采用扫描电镜观察骨结合的状态。结果分别对不同加载力值及加载时间各组的扫描电镜图片进行对比观察,各组种植体-骨结合界面在形态学上均无显著性差异,均表现为:种植体与周围骨质结合良好,表面有大量骨质覆盖。种植体与其周围骨质间存在微小间隙,间隙均小于0.85 mm。结论微钛螺纹钉种植体即刻加载300 g以内的水平力不影响支抗种植体的稳定性。

Objective To evaluate the effects of the various timing and loading force on osseointegration interface of titanium mini-screw implants. Methods In 5 Beagle dogs, 9 titanium mini-screw implants were installed on each side of maxilla. The implants were loaded by using NiTi-screw extension springs with 100 g or 300 g constant force immediately, and at week 2, week 4 and week 8, respectively. Control groups were unloaded. At week 20, animals were sacrificed and specimens were prepared containing the mini-screw implants and 2 mm surrounding tissue. Osseointegration was observed by scanning electron microscope （SEM）. Results A comparative analysis on SEM images from groups with different loading forces and time was performed. The implant osseointegration interface of different groups showed no significant morphological differences, demonstrating solidly the bonded interfaces of implants and surrounding bones, as well as bone covered surfaces of implants. Micro-gaps were less than 0.85 mm between mini-screw implants and bone tissue. Conclusion Immediate loading application of the titanium mini-screw implants with less than 300 g force does not influence the stability of implant anchorage.