静动载作用下牙冠的断裂失效模式

FRACTURE OF TOOTH CROWNS UNDER STATIC AND IMPACT LOADINGS

正常牙齿存在许多薄弱结构,如窝沟、楔状缺损和牙隐裂等.如何评估这些薄弱结构对牙齿裂纹产生和断裂的影响,一直缺乏有效的评价方法.利用实验和有限元分析两种方法,初步分析了牙冠在静动载荷作用下的断裂模式.研究结果表明,结构因素是决定牙冠断裂的最重要因素,牙冠断裂常常发生在结构薄弱的地方,且牙冠断裂符合第二强度准则.本研究为临床诊断和治疗提供一定的理论依据.

The normal teeth involve many weak structures,such as pit andˉssure,wedge-shaped defect,and cracked tooth.It remains an issue to be explored how to evaluate the effect of these weak structures on the crack initiation and the fracture of the teeth,due to limited evaluation methods.This paper analyzes the failure modes of the dental crown under static and dynamic loads by experimental and numerical methods.It is shown that the weak structures are the determinative factors of the crown fractures,which are in line with the second strength theory.The results of this study will provide a theoretical basis for clinical diagnoses and treatments.