Correlation Between Stress Distributions and Biological Reactions in Bone Surrounding Implants That Support Cantilevers in Supraocclusal Contact in Rats
Correlation Between Stress Distributions and Biological Reactions in Bone Surrounding Implants That Support Cantilevers in Supraocclusal Contact in Rats
复制标题
大鼠咬合上接触中支撑悬臂的骨周围植入物的应力分布与生物反应之间的相关性
DOI：
10.1097/id.0000000000000369
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发表时间：
2016
影响因子：
--
通讯作者：
Uoshima K
中科院分区：
文献类型：
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作者：
Takano R;Nagasawa M;Kitami M;Rosales Rocabado JM;Kaku M;Stegaroiu R;Uoshima K
目的：探讨上颌种植体在咬合上接触时支撑悬臂的应力分布与种植体周围骨反应的关系。材料与方法：16只Wistar大鼠拔牙后单侧种植钛。愈合后处死8只大鼠（对照组），其余大鼠在咬合上放置种植体支撑的悬臂结构（加载组）。5天后，他们被杀了。采用微计算机断层扫描（μ-CT）对各组大鼠上颌进行扫描。根据μ-CT图像测量骨体积。加载组分别在竖向20 n和侧向5 n荷载作用下建立三维有限元模型并进行分析。μ-CT扫描后，制备切片并进行组织学观察。结果：与对照组相比，负重组骨体积有减小的趋势，但差异无统计学意义。平均而言，在悬臂臂上闭塞的2只大鼠的边缘骨吸收和应力往往高于在种植体上闭塞的2只大鼠，但计算出的应力没有超过大鼠骨的最大弹性应力（屈服强度）。然而，在这些样品的种植体-骨界面，组织学上发现部分骨吸收周围有主动吸收的迹象。结论：本研究结果提示，在封闭负荷大鼠模型中，应力分布与骨体积及显微组织切片观察到的形态学变化有一定的相关性。
Purpose:To investigate the relationship between stress distributions and peri-implant bone reactions around maxillary implants that support cantilevers in supraocclusal contact.Materials and Methods:After molar extraction, 16 Wistar rats received a titanium implant unilaterally. After healing, 8 rats (control group) were killed and the others received implant-supported cantilever superstructures in supraocclusion (loaded group). After 5 days, they were killed. The maxillae of all rats were scanned by microcomputed tomography (μ-CT). Based on the μ-CT images, bone volumes were measured. For the loaded group, 3D finite element models were created and analyzed under 20-N vertical and 5-N lateral forces, successively. After μ-CT scanning, sections were prepared and observed histologically.Results:When compared with the controls, the bone volume tended to decrease in the loaded group, but the difference was not statistically significant. On average, marginal bone resorption and stresses tended to be higher in 2 rats that occluded on the cantilever arm than in the others, which occluded right on the implant, nevertheless, calculated stress did not surpass the maximum elastic stress (yielding strength) of rat bone. However, at the implant-bone interface of these samples, partial bone resorption surrounded by signs of active resorption was histologically found.Conclusion:These findings suggest that in this occlusally loaded rat model, the stress distributions correlated to some extent with bone volume and morphological changes observed on μ-CT images and histological sections.