Du Jing, Lee Ji-Hyun, Jang Andrew T, Gu Allen, Hossaini-Zadeh Mehran, Prevost Richard, Curtis Donald A, Ho Sunita P
Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA.
Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA; Department of Oral and Maxillofacial Surgery, School of Dentistry, University of California San Francisco, CA, USA.
J Biomech. 2015 Sep 18;48(12):3486-94. doi: 10.1016/j.jbiomech.2015.05.014. Epub 2015 Jun 19.
The effects of alveolar bone socket geometry and bone-implant contact on implant biomechanics, and resulting strain distributions in bone were investigated. Following extraction of lateral incisors on a cadaver mandible, implants were placed immediately and bone-implant contact area, stability implant biomechanics and bone strain were measured. In situ biomechanical testing coupled with micro X-ray microscopy (µ-XRM) illustrated less stiff bone-implant complexes (701-822 N/mm) compared with bone-periodontal ligament (PDL)-tooth complexes (791-913 N/mm). X-ray tomograms illustrated that the cause of reduced stiffness was due to limited bone-implant contact. Heterogeneous elemental composition of bone was identified by using energy dispersive X-ray spectroscopy (EDS). The novel aspect of this study was the application of a new experimental mechanics method, that is, digital volume correlation, which allowed mapping of strains in volumes of alveolar bone in contact with a loaded implant. The identified surface and subsurface strain concentrations were a manifestation of load transferred to bone through bone-implant contact based on bone-implant geometry, quality of bone, implant placement, and implant design. 3D strain mapping indicated that strain concentrations are not exclusive to the bone-implant contact regions, but also extend into bone not directly in contact with the implant. The implications of the observed strain concentrations are discussed in the context of mechanobiology. Although a plausible explanation of surgical complications for immediate implant treatment is provided, extrapolation of results is only warranted by future systematic studies on more cadaver specimens and/or in vivo models.
研究了牙槽骨窝几何形状和骨-种植体接触对种植体生物力学以及由此产生的骨应变分布的影响。在一具尸体下颌骨上拔除侧切牙后,立即植入种植体,并测量骨-种植体接触面积、种植体稳定性生物力学和骨应变。原位生物力学测试与微型X射线显微镜(µ-XRM)相结合表明,与骨-牙周韧带(PDL)-牙齿复合体(791-913N/mm)相比,骨-种植体复合体的刚度较低(701-822N/mm)。X射线断层扫描表明,刚度降低的原因是骨-种植体接触有限。通过能量色散X射线光谱(EDS)确定了骨的异质元素组成。本研究的新颖之处在于应用了一种新的实验力学方法,即数字体积相关法,该方法能够绘制与加载种植体接触的牙槽骨体积中的应变。所确定的表面和亚表面应变集中是基于骨-种植体几何形状、骨质量、种植体植入位置和种植体设计,通过骨-种植体接触传递到骨的载荷的一种表现。三维应变映射表明,应变集中不仅限于骨-种植体接触区域,还延伸到未与种植体直接接触的骨中。在力学生物学的背景下讨论了观察到的应变集中的影响。尽管为即刻种植治疗的手术并发症提供了一个合理的解释,但只有通过对更多尸体标本和/或体内模型进行未来的系统研究,才能保证结果的外推。