基于纳米压痕实验的犬牙周膜弹性模量研究

Evaluation of the elastic modulus of Beagle's periodontal ligament with nanoindentation technology

目的:应用纳米压痕技术定量测定比格犬牙周膜弹性模量,为准确建立牙周膜本构模型奠定基础。方法:对于24个比格犬下颌第一磨牙牙根横断面切片试样,采用纳米压痕技术沿牙长轴不同层面和同一层面牙根不同方位的牙周膜位点压入、卸载,获取加载-位移曲线,计算弹性模量,进行统计分析。结果:基于纳米压痕法测得比格犬牙周膜下颌磨牙弹性模量约为0.452~1.542 MPa。沿牙长轴不同牙根层面的牙周膜弹性模量没有显著差异,牙根同一层面不同方位(颊舌侧、近远中侧)的牙周膜弹性模量存在显著差异(P<0.05)。结论:比格犬同一牙根的颊舌侧与近远中侧牙周膜弹性模量存在差异。

Objective： To evaluate the elastic modulus of Beagle＇s periodontal ligament （PDL） by means of nanoindentation, and to help build constitutive model of PDL precisely. Methods： 24 cross sections were obtained from the tooth root of lower first molars of beagle dog. With nanoindentation, intrusion and unloading to PDL sites on different planes of long axial and in different directions on the same plane of tooth root were achieved, and the load- displacement curves were obtained, from which the elastic modulus was calcu- lated and analyzed. Results： The elastic modulus of the beagleb periodontal ligament varied from 0. 452 - 1. 542 MPa. There was no significant difference in elastic modulus of the beagleg lower first premolar PDL in relation to different planes of long axial, while signifi- cant difference was found in different directions （ buccal/lingual sides and mesial/distal sides） on the same plane of tooth root （P 〈 0.05）. Conclusion： There was a difference in the elastic modulus of periodontal ligament in buccal/lingual sides and mesial/distal sides of the same tooth root.