南京大学学报（自然科学版）2017，Vol.53Issue(1)：92-101,10.DOI:10.13232/j.cnki.jnju.2017.01.013
激光超声纵波用于磨牙内部轮廓无损检测的理论研究
Theoretical study of laser ultrasonic longitudinal wave applied in thenondestructive detection of inner profile of molars
摘要
Abstract
Although the external contour information of the teeth is easy to be measured in clinic,the clinical detection of the internal profile-enamel-dentinal junction has not been realized.This paper proposes a method of using laser ultrasonic longitudinal wave to detect the internal profile of the molar.Firstly,the ultrasonic wave generated by the irradiation of the teeth with laser was simulated by the finite element method.Three dimensional model of tooth was acquired by CT scan and 3D reconstruction technique,and then the finite element model of ultrasonic longitudinal wave and longitudinal wave propagation was established.When the laser was irradiated on the surface of the enamel,some of the laser energy would penetrate into the depth of the enamel.Considering this situation,the position of equivalent point source was modified.One cross section of the molar was selected.Because of the uneven thickness of the enamel in all directions,it was necessary to rotate it.And then multiple ultrasonic signals were received at the same side of the excitation point.According to the signal analysis,the position of the reflection point of the longitudinal wave in the enamel-dentinal junction(EDJ)was solved,and the detection of inner profile of the tooth was finally realized.Compared with the actual tooth profile,the accuracy of the results is high,which verifies the feasibility of using laser ultrasonic longitudinal wave to detect the inner contour of the teeth.Finally,the error sources of the method and its application conditions were analyzed.The main measurement error is caused by the change of enamel thickness.The results of the study will provide theoretical basis and detection methods for the clinical detection of the internal structure of teeth.It is helpful for the further development and application of laser ultrasonic technology in clinical medicine detection.关键词
激光超声/无损检测/有限元方法/牙齿结构/纵波Key words
laser ultrasound/non-destructive evaluation/finite element method/tooth structure/longitudinal wave分类
信息技术与安全科学引用本文复制引用
徐海云,梅松,袁玲,沈中华,朱庆萍,倪晓武,陆健..激光超声纵波用于磨牙内部轮廓无损检测的理论研究[J].南京大学学报（自然科学版）,2017,53(1):92-101,10.基金项目
国家自然科学基金青年基金(61108013),南京理工大学"紫金之星"项目 （61108013）
