[论文解读] The interplay between tissue healing and bone remodeling around immediately loaded tooth replacement implants

Soroush Irandoust, Sinan Müftü|arXiv (Cornell University)|Jul 18, 2019

Dental Implant Techniques and Outcomes参考文献 49被引用 9

一句话总结

本研究采用一种机械调节性多孔弹性模型，模拟即刻负重牙科种植体周围组织的愈合与骨改建过程，结果表明：受控的微动可优化骨形成：微动较小则促进初始骨分化，随后发生骨吸收；微动较大则增加软组织形成，同时提高剩余骨组织的密度，提示存在一个最佳微动范围以实现功能整合。

ABSTRACT

Long-term bone healing/adaptation after a dental implant treatment starts with diffusion of mesenchymal stem cells to the fracture callus and their subsequent differentiation. The healing phase is followed by the bone-remodeling phase. In this work, a mechano-regulatory cellular differentiation model was used to simulate tissue healing around an immediately loaded dental implant. All tissue types were modeled as poroelastic in the healing phase. Material properties of the healing region were updated after each loading cycle for 30 cycles (days). The tissue distribution in the healed state was then used as the initial condition for the remodeling phase during which regions healed into bone adapt their internal density with respect to a homeostatic remodeling stimulus. The short- and long-term effects of micro-motion on bone healing and remodeling were studied. Development of soft tissue was observed both in the coronal region due to high fluid velocity, and on the vertical sides of the healing-callus due to high shear stress. In cases with small implant micromotion, tissue between the implant threads differentiated into bone during the healing phase, but resorbed during remodeling. In cases with large implant micromotion, higher percentage of the healing region differentiated into soft tissue resulting in less volume available for bone remodeling. But, the remaining bone region developed higher density bone tissue. It was concluded that an optimal range of controlled micromotion could be designed for a given implant in order to achieve the desired functional properties.

研究动机与目标

• 理解即刻牙科种植体负重后组织愈合与骨改建之间的相互作用。
• 识别不同水平的种植体微动对组织分化与骨适应的影响。
• 确定促进功能骨形成与长期种植体稳定性的最佳微动范围。

提出的方法

• 应用多孔弹性模型模拟愈合阶段，每完成30个加载循环后更新组织特性。
• 细胞分化由基于机械刺激（如流体速度和剪切应力）的机械调节模型控制。
• 愈合后组织分布作为骨改建阶段的初始条件。
• 在改建阶段，基于稳态改建刺激模拟骨密度适应。
• 系统性地改变微动水平，以评估其对组织类型分布与骨密度的影响。

实验结果

研究问题

• RQ1 微动如何影响即刻负重种植体周围愈合阶段的组织分化？
• RQ2 微动对愈合区域软组织与骨组织分布有何影响？
• RQ3 微动如何影响长期改建阶段的骨密度适应？
• RQ4 能否识别出一个最佳微动范围以最大化功能骨形成？
• RQ5 哪些机械因素（如流体速度、剪切应力）驱动愈合区域的软组织发育？

主要发现

• 冠状区域的高流体速度因血流动力学力促进软组织发育。
• 愈合骨痂垂直侧壁的高剪切应力促进软组织形成。
• 微动较小时，愈合阶段种植体螺纹间的组织分化为骨组织，但在改建阶段发生吸收。
• 微动较大时，愈合区域中更高比例的组织转化为软组织，减少了可用于骨改建的体积。
• 剩余骨组织区域因机械刺激增强而发展出更高的密度。
• 存在一个最佳微动范围，可在组织分化与骨密度之间实现平衡，从而改善种植体整合。