The fracture behaviour of dental enamel
The fracture behaviour of dental enamel
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DOI：
10.1016/j.biomaterials.2009.09.050
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发表时间：
2010-01-01
期刊：
影响因子：
14
通讯作者：
Schneider, Gerold A.
中科院分区：
文献类型：
--
作者：
Bechtle, Sabine;Habelitz, Stefan;Schneider, Gerold A.
釉质是人体内最硬的组织，覆盖在牙冠上。虽然牙本质在力学和断裂性能方面具有很好的特性，但有关牙釉质的现有数据非常有限，与主要基于压痕研究的最新研究相去甚远。在本研究中，我们已经在牛牙釉质中进行了稳定的裂纹扩展实验，以测量牙釉质的断裂阻力曲线。从牛门牙制备的单边缺口弯曲试件(SENB)进行了三点弯曲试验，并随后用光学和环境扫描电子显微镜进行了分析。裂纹主要在富含蛋白质的杆鞘内扩展，裂纹扩展发生在与初始缺口方向成斜角的情况下，不仅是由于釉质棒和羟基磷灰石微晶的取向，而且可能是由于蛋白质的剪切。测得的I型断裂阻力曲线从裂纹扩展开始时的0.8~1.5 Mpa*m(1/2)到裂纹扩展500亩时的4.4 Mpa*m(1/2)，相应的I型值在0.3~1.5 Mpa*m(1/2)之间。(C)2009爱思唯尔有限公司。保留所有权利。
Enamel is the hardest tissue in the human body covering the crowns of teeth. Whereas the underlying dental material dentin is very well characterized in terms of mechanical and fracture properties, available data for enamel are quite limited and are apart from the most recent investigation mainly based on indentation studies. Within the current study, stable crack-growth experiments in bovine enamel have been performed, to measure fracture resistance curves for enamel. Single edge notched bending specimens (SENB) prepared out of bovine incisors were tested in 3-point bending and subsequently analysed using optical and environmental scanning electron microscopy. Cracks propagated primarily within the protein-rich rod sheaths and crack propagation occurred under an inclined angle to initial notch direction not only due to enamel rod and hydroxyapatite crystallite orientation but potentially also due to protein shearing. Determined mode I fracture resistance curves ranged from 0.8-1.5 MPa*m(1/2) at the beginning of crack propagation up to 4.4 MPa*m(1/2) at 500 mu m crack extension; corresponding mode II values ranged from 0.3 to 1.5 MPa*m(1/2). (C) 2009 Elsevier Ltd. All rights reserved.