New observations of the hierarchical structure of human enamel, from nanoscale to microscale
New observations of the hierarchical structure of human enamel, from nanoscale to microscale
复制标题
DOI：
10.1002/term.21
复制
发表时间：
2007-05-01
影响因子：
3.3
通讯作者：
Ge, Jun
中科院分区：
文献类型：
--
作者：
Cui, Fu-Zhai;Ge, Jun
在矿化生物材料中广泛存在层次组装的微观结构，对构筑矿化生物材料的优异性能起着重要作用。本研究的目的是探讨牙釉质结构和功能的分层组装，这与牙釉质的独特特性有关。采用扫描电子显微镜（SEM）、高分辨率透射电子显微镜（HRTEM）和原子力显微镜（AFM）对人成熟第三磨牙牙釉质进行了研究。结合显微观察结果，揭示了牙釉质结构在等级组装方面的高度复杂性。基于这些观察，我们提出并描述了七个微观结构层次，使用了一个详细代表组织的完整光谱的方案，涵盖了从微尺度到纳米尺度的范围：羟基磷灰石晶体（1级）首先形成矿物纳米纤维（2级）；纳米原纤维总是纵向排列，聚集成原纤维（3级）和更厚的纤维（4级）；棱镜/棱镜间连续体（5级）由它们组成。在微观尺度上，棱柱组合成棱柱带（6级），棱柱带在牙釉质层的厚度上呈现不同的排列（7级）。对牙釉质和骨骼等级结构的分析表明，每一级的鳞片分布相似。本研究还旨在进一步了解各个层次的结构-力学关系。版权所有(C) 2007约翰威利父子有限公司
Microstructure in terms of hierarchical assembly exists widely in mineralized biomaterials, fulfilling an important role in setting up their outstanding properties. The purpose of this study was to investigate the hierarchical assembly of enamel structure and functions, which are related to the unique characteristics of enamel. Human enamel taken from mature third molars was explored using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and atomic force microscopy (AFM). Integrating the microscopic observations revealed the high complexity of the well-organized enamel structure in terms of hierarchical assembly. Based on these observations, seven hierarchical levels of the microstructure were proposed and described, using a scheme representing a complete spectrum of the organization in detail, covering a range from microscale to nanoscale: hydroxyapatite crystals (Level 1) at first form mineral nanofibrils (Level 2); the nanofibrils always align lengthways, aggregating into fibrils (Level 3) and further thicker fibres (Level 4); prism/interprism continua (Level 5) are then composed of them. At the microscale, prisms assemble into prism bands (Level 6), which present different arrangements across the thickness of the enamel layer (Level 7). Analysis of the enamel and bone hierarchical structure suggests similarities of scale distribution at each level. This study also aimed to understand further the structural-mechanical relations at each hierarchical level. Copyright (C) 2007 John Wiley & Sons, Ltd.