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A STUDY ON THE MECHANISM OF TOOTH FRACTURE

牙齿骨折发生机制的研究

基本信息

批准号：
08672204
负责人：
TAKATSU Toshio
金额：
$ 1.15万
依托单位：
OHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08672204/
关键词：
tooth fracture fractured tooth tooth root fracture 象牙破折

项目摘要

This study was performed on the following two parts.1.Observations of the fragments obtained from the fractured molars in-vivo.The fragments were obtained from the first molars of the patients suffering from vertical fracture (case 1,2,3). They were subjected to the fractographycal analysis through optical and SEM observations, obtaining the following findings.On the individual fractured surfaces, various structures were observed. Namely, in case 1, manywave-shaped structures were found running in parallel with dentinal tubules. In case 2, rib-marks of various size and small hackle marks were found around apical area and coronally propagating. In case 3, many river patterns were found initiating coronally and apically running, inacreasing their sizes.2.Observations of the experimentally fractured tooth surfacesThe extracted human upper central incisors were horizontally sectioned around the cervix. Then, the root was vertically split coronally (group 1) or apically (group 2) with a knife and mallet.In group 1, many river patterns were found apically running, increasing their sizes and diverting laterally. In group 2, rib marks were found initiating together with many hackle marks, propagating coronally.Analysis of the findings seems to indicate that the in-vivo molars rapidly fractured presenting the brittle fracture patterns.

本研究分为两个部分：1.离体磨牙纵折断块的观察：取纵折患者第一磨牙（例1、例2、例3）的离体磨牙断块。通过光学和扫描电子显微镜观察对它们进行了断口分析，得到了以下结果：在各个断裂表面上，观察到了各种结构。即在病例1中，发现许多波形结构与牙本质小管平行。例2根尖周围可见大小不一的肋痕和小的梳齿痕，并向冠状面扩展。例3中，发现许多河流图案起始于冠部和顶部，增加了它们的大小。2.实验性牙面断裂的观察然后，用刀和木槌垂直劈开根的冠状（组1）或顶部（组2），在组1中，发现许多河流图案的顶部运行，增加其大小和转向横向。第2组中，发现肋骨痕迹与许多梳齿痕迹一起起始，并向冠状扩展。分析结果似乎表明，体内磨牙迅速断裂，呈现脆性断裂模式。