纳米硬度仪测量人类牙釉质的纳米力学性能分布

Nanomechanical mapping within human dental enamel by nanoindentation

目的:人牙釉质内的力学性能分布,对实现釉质的优异性能起到了重要作用,因而本工作的目的是使用结合原子力显微镜(Atom ic Force M icroscope,AFM)的纳米压痕仪,在纳米尺度上精确测量其分布特点。方法:釉质样本取自成人第三磨牙。使用由AFM控制的纳米压痕仪,定点精确测量釉质样品内的釉柱、釉柱间质和釉质鞘区域的纳米硬度和弹性模量。测量后,用AFM观察压痕形貌。结果:对纳米力学性能的测量结果显示出显著差异,釉质鞘和柱间质的纳米硬度比釉柱的硬度分别低73.5%和12.9%,其弹性模量分别下降了52.6%和7.1%。对压痕形貌的观察也得到了同样的结果。结论:本工作精确测量了人牙釉质的釉柱、柱间质以及釉质鞘的纳米硬度和弹性模量分布。纳米力学性能存在的差异性主要与成分及晶体排列方式有关。

AIM：The purpose of the present study is to accurately map the mechanical distribution in human enamel at nanoscale that significantly contributes to the outstanding functions of enamel using nanoindentation combined with Atomic Force Microscope （AFM）. METHODS：Enamel was distilled from mature human third molars. Nanoindentation ,controlled by AFM ,was performed to site -specifically test nanohardness and elastic modulus of the prisms, interprisms and surrounding sheath in prepared enamel samples. After t,the residual impressions were scanned using AFM, RESULTS：Evident differences of nanomechanical properties were revealed among these domains. The values of nanohardness measured from sheaths and interprisms were 73.5% and 12.9% lower than that from the prisms respectively,while the values of elastic modulus were 52.6% and 7.1% lower respectively. Measuring the residual impressions with AFM supported the similar conclusion. CONCLUSION：The mechanical mapping within human enamel was detected. The variations measured are considered to be mainly relative to the different components and crystal arrangements.