On the systematic documentation of the structural characteristics of bovine enamel: A critic to the protein sheath concept.
On the systematic documentation of the structural characteristics of bovine enamel: A critic to the protein sheath concept.
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DOI：
10.1016/j.dental.2018.06.006
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发表时间：
2018-10
期刊：
影响因子：
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通讯作者：
Ezgi D. Yilmaz;J. Koldehoff;G. Schneider
中科院分区：
文献类型：
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作者：
Ezgi D. Yilmaz;J. Koldehoff;G. Schneider
在材料科学研究中使用的牛牙釉质的常见结构描述-纳米尺寸的羟基磷灰石微晶形成被蛋白质鞘包围的微米尺寸的棱柱，这反过来又构建了复杂的交叉图案-忽略了许多重要的形态信息。这妨碍了对通过力学分析确定的数据的正确解释。对于一个深刻的结构描述的釉质形态，可视化的高分辨率电子显微镜和聚焦离子束断层扫描技术，揭示了它们的形式，方向和配置在不同区域的牙齿（在不同的方向切割），其积木进行这项工作。我们适应在这里的古生物学分类系统和术语开发的描述在不同物种中看到的釉质微观结构，并相应地记录了牛切牙釉质的形态奇异性。微晶和棱柱之间的边界区域的外观与众所周知的蛋白质鞘的概念相矛盾。相邻的微晶和棱柱没有被突出的间隙区分开，但它们彼此大部分接触。蛋白质可能存在于大小为20-30 nm的孔中，其通过边界区域不均匀地分布，而不是作为覆盖每个微晶和棱柱的蛋白质鞘。
The common structural description of bovine enamel used in materials science studies – nano-sized hydroxyapatite crystallites form micron-sized prisms surrounded by protein sheaths, which in turn build a complex decussation pattern – overlook many important morphological information. This hampers the correct interpretation of the data determined by mechanical analysis. For a profound structural description of enamel morphology, the visualization of its building blocks by high-resolution electron microscopy and focused-ion beam tomography technique, which reveals their form, orientation and configuration at different regions of a tooth (cut in different directions), is undertaken in this work. We adapted here the paleontological classification system and terminology developed for the description of enamel microstructures seen in different species, and accordingly documented the morphological singularities of bovine incisor enamel. The appearance of the boundary regions between crystallites and prisms contradicts to the well-known protein sheath concept. Neighboring crystallites and prisms are not separated by prominent gap zones but they are largely in contact with each other. Proteins might exist within the pores of 20–30 nm in size, which are distributed inhomogeneously through the boundary regions, rather than as protein sheaths covering each crystallite and prism.