Department of Mechanical Engineering of National Chung Cheng University, Chia-Yi, 62100, Taiwan.
J Mech Behav Biomed Mater. 2011 May;4(4):515-22. doi: 10.1016/j.jmbbm.2010.12.002. Epub 2010 Dec 15.
The AFM combined nanoindentation was performed to observe the ultrastructure of enamel rod from various section plans and positions while probing their mechanical and tribological properties of the area. The nanohardness and the elastic modulus of the head region of the enamel rods are significantly higher than that of the tail region and the axial-sectional plane. Both nanohardness and elastic modulus gradually decrease from enamel surface toward dentino-enamel junction. Such a variation correlates well with the decreasing trend of calcium composition from our element analysis. The friction coefficient and nanowear of the enamel showed an inversed trend to the hardness with respect to their relative topological position in the long axis of enamel rod toward DEJ. The relationship between the nanowear depth and the distance from the outer enamel surface to DEJ presented exponential function. The results presented clarify the basic nanomechanical and nanotribological properties of human enamel rods and provide a useful reference for the future development of dental restorative materials.
采用原子力显微镜结合纳米压痕技术，从不同的剖面和位置观察釉柱的超微结构，并对其区域的机械和摩擦学性能进行探测。釉柱头部的纳米硬度和弹性模量明显高于尾部和轴向剖面。纳米硬度和弹性模量从釉面到牙釉质牙本质交界处逐渐降低。这种变化与我们的元素分析中钙成分的降低趋势很好地相关。釉质的摩擦系数和纳米磨损与硬度呈相反趋势，与釉柱长轴上相对于 DEJ 的相对拓扑位置有关。纳米磨损深度与从外釉面到 DEJ 的距离之间呈指数函数关系。这些结果阐明了人釉柱的基本纳米力学和纳米摩擦学特性，为未来牙科修复材料的发展提供了有益的参考。
