纳米压痕法用于人下颌骨弹性模量的测量

目的:对既往文献中所采用的纳米压痕技术进行横向比较并推荐出制作时间短、对实验结果影响较小的实验项目。方法:获取一具人新鲜尸体下颌骨,应用推荐的实验方法指导试件制备、纳米压痕及结果分析,设定压入载荷分别为1、2、3、4、5mN,最大载荷保持时间为0、10、30、60s,分析测出的颌骨弹性模量(E),对载荷—深度曲线进行初步解析。结果:在人下颌骨的纳米压痕测试时,当压入载荷为3～5mN、最大载荷保持时间为10s及以上,所得测试结果对弹性模量值的影响较小。结论:本文确定了颌骨测试时推荐使用的压入载荷大小及最大载荷的保持时间,并应用纳米压痕测试法测试得到人下颌骨磨牙区皮质骨的平均弹性模量(E)值为18GPa。

Elastic Properties of Human Mandibule Measured by Nanoindentation

Objective：Nano-indentation of bones recently has been further developed because of the materials and test techniques＇ improvement.We compared the latest articles and our tests with the early literatures about nano-indentation of bones,and made an argument.The aim of this paper was to reduce or eliminate some interference factors in the period of experiment and to determine whether changes in the max load and pause time are related to bone elastic modulus（E）.The viscoelastic behavior of bones and load-displacement curve were also explained.Methods：A fresh mandibular bone was harvest and then cut into several sections to test by recommended nano-indentaion method.This method instructed specimen preparation,nano-indentaion and result analysis.Different Max loads at 1,2,3,4,5mN,and different pause time at 0,10,30,60s,were set respectively and measured.Results：With a max load at 3~5mN and a pause time at 10s or more,the test could give a precise and repeatable elastic modulus.Our test method reduced the duration of specimen preparation and water loss,and might get nearer results as bones in internal environment.Conclusion：Our study measured mandibular molar region cortical bone＇s elastic modulus with nano-indentation,and concluded the E was at a 18Gpa level in average.