Ivanoff C J, Sennerby L, Lekholm U
Brånemark Clinic, Public Dental Health Service and Faculty of Odontology, University of Göteborg, Sweden.
Clin Oral Implants Res. 1996 Jun;7(2):120-7.
In the present study, the influence of initial instability on the healing of titanium implants was studied in 9 lop-eared rabbits. Titanium implants (Brånemark System) were inserted in the tibiae, a location with cortical bone only, in such a way that they were either stable (control), rotation-mobile, or totally mobile. Implants were also inserted in the distal femoral condyles, representing an implantation bed with mainly cancellous bone, so they either showed no initial mobility (control) or were rotation-mobile. After 12 weeks of healing, the implants were retrieved, together with surrounding bone, fixed, dehydrated, and embedded in plastic resin. About 10 micron thick ground sections were prepared for light microscopic morphometry. The mineralized bone to titanium contact, and the amount of bone occupying the threads, were calculated, whereafter the outcome of the different locations were compared. All retrieved implants were clinically stable at the of the experiment. For the tibia sites, a statistically significant less bone to titanium contact, and a less amount of bone in the threads, were found for the totally mobile implants, as compared to the corresponding initially stable controls. Moreover, a statistically significant higher amount of bone was found in the threads of the rotation-mobile implants inserted in the femoral condyle as compared to their initially stable controls. The study indicated that initial rotation-mobility, independent if it occurs in cortical or trabecular bone, does not necessarily lead to an inferior integration of unloaded implants. However, initial total implant mobility within the cortical layer results in a statistically significant less amount of bone around the implants, as compared to stable controls.
在本研究中，在9只垂耳兔身上研究了初始不稳定性对钛植入物愈合的影响。将钛植入物（Brånemark系统）植入胫骨，该部位仅有皮质骨，植入方式使其要么稳定（对照）、可旋转移动，要么完全移动。植入物也被插入股骨远端髁，代表主要为松质骨的植入床，因此它们要么没有初始移动性（对照），要么可旋转移动。愈合12周后，取出植入物连同周围骨组织，进行固定、脱水，并嵌入塑料树脂。制备约10微米厚的磨片用于光学显微镜形态计量学分析。计算矿化骨与钛的接触面积以及占据螺纹的骨量，然后比较不同部位的结果。在实验结束时，所有取出的植入物在临床上都是稳定的。对于胫骨部位，与相应的初始稳定对照相比，完全移动的植入物的骨与钛接触面积在统计学上显著减少，螺纹中的骨量也较少。此外，与初始稳定对照相比，插入股骨髁的可旋转移动植入物的螺纹中骨量在统计学上显著更高。该研究表明，初始旋转移动性，无论发生在皮质骨还是小梁骨中，不一定会导致无负载植入物的整合较差。然而，与稳定对照相比，皮质层内植入物的初始完全移动会导致植入物周围的骨量在统计学上显著减少。
