AO Research Institute Davos, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland.
ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland.
J Mech Behav Biomed Mater. 2024 Oct;158:106688. doi: 10.1016/j.jmbbm.2024.106688. Epub 2024 Aug 12.
Adequate primary stability is a pre-requisite for the osseointegration and long-term success of dental implants. Primary stability depends essentially on the bone mechanical integrity at the implantation site. Clinically, a qualitative evaluation can be made on medical images, but finite element (FE) simulations can assess the primary stability of a bone-implant construct quantitatively based on high-resolution CT images. However, FE models lack experimental validation on clinically relevant bone anatomy. The aim of this study is to validate such an FE model on human jawbones. Forty-seven bone biopsies were extracted from human cadaveric jawbones. Dental implants of two sizes (Ø3.5 mm and Ø4.0 mm) were inserted and the constructs were subjected to a quasi-static bending-compression loading protocol. Those mechanical tests were replicated with sample-specific non-linear homogenized FE models. Bone was modeled with an elastoplastic constitutive law that included damage. Density-based material properties were mapped based on μCT images of the bone samples. The experimental ultimate load was better predicted by FE (R = 0.83) than by peri-implant bone density (R = 0.54). Unlike bone density, the simulations were also able to capture the effect of implant diameter. The primary stability of a dental implant in human jawbones can be predicted quantitatively with FE simulations. This method may be used for improving the design and insertion protocols of dental implants.
足够的初始稳定性是牙种植体骨整合和长期成功的前提。初始稳定性主要取决于种植部位的骨机械完整性。临床上，可以在医学图像上进行定性评估，但有限元（FE）模拟可以根据高分辨率 CT 图像对骨-种植体结构的初始稳定性进行定量评估。然而，FE 模型缺乏对临床相关骨解剖结构的实验验证。本研究的目的是在人颌骨上验证这种 FE 模型。从人尸体颌骨中提取了 47 个骨活检样本。将两种尺寸（Ø3.5mm 和 Ø4.0mm）的牙种植体插入，并对构建体进行准静态弯曲-压缩加载方案。对具有特定样本的非线性均匀化 FE 模型进行了这些机械测试的复制。骨骼采用包含损伤的弹塑性本构定律进行建模。基于骨骼样本的μCT 图像，对基于密度的材料特性进行了映射。FE 模拟（R=0.83）比种植体周围骨密度（R=0.54）更好地预测了实验的极限载荷。与骨密度不同，模拟还能够捕捉到种植体直径的影响。使用 FE 模拟可以定量预测人颌骨中牙种植体的初始稳定性。这种方法可用于改进牙种植体的设计和插入方案。
