Variations in the Mechanical Properties of Alouatta palliata Molar Enamel
Variations in the Mechanical Properties of Alouatta palliata Molar Enamel
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DOI：
10.1002/ajpa.21126
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发表时间：
2010-01-01
影响因子：
2.8
通讯作者：
Weihs, Timothy P.
中科院分区：
文献类型：
--
作者：
Darnell, Laura A.;Teaford, Mark F.;Weihs, Timothy P.
牙齿提供了对许多主题的见解，包括灵长类动物的饮食、古生物学和进化，因为它们主要由无机材料组成，可能在动物死亡后很长一段时间内保持完好。以往的研究已经报道，人牙釉质的力学性能、化学成分和微观结构随位置的不同而变化。本研究使用纳米压痕技术，在未磨损的第三恒磨牙、磨损的第一恒磨牙和磨损的乳磨牙的轴向横截面上绘制出Alouatta palliata磨牙釉质的力学性能图。然后使用扫描电子显微镜和电子探针技术将变化与微观结构和化学变化相关联。从咬合面到牙本质牙釉质交界处，从颊到舌侧，以及从一颗牙齿到另一颗牙齿的横断面上，硬度和杨氏模数随位置的变化而变化。这些力学性能的变化与牙齿有机含量的变化有关，在DEJ之前，牙齿有机含量从接近咬合面的6%增加到类似20%。与人类牙釉质相比，Alouatta牙釉质表现出类似的微观结构、化学成分和大量的机械性能，但在硬度和杨氏模数方面变化较小，尽管这两个物种的饮食非常不同。Am J Phys Anthropol141：7-15,2010.(C)2009年Wiley-Liss，Inc.
Teeth have provided insights into many topics including primate diet, paleobiology, and evolution, due to the fact that they are largely composed of inorganic materials and may remain intact long after an animal is deceased. Previous studies have reported that the mechanical properties, chemistry, and microstructure of human enamel vary with location. This study uses nanoindentation to map out the mechanical properties of Alouatta palliata molar enamel on an axial cross-section of an unworn permanent third molar, a worn permanent first molar, and a worn deciduous first molar. Variations were then correlated with changes in microstructure and chemistry using scanning electron microscopy and electron microprobe techniques. The hardness and Young's modulus varied with location throughout the cross-sections from the occlusal surface to the dentin-enamel junction (DEJ), from the buccal to lingual sides, and also from one tooth to another. These changes in mechanical properties correlated with changes in the organic content of the tooth, which was shown to increase from similar to 6% near the occlusal surface to similar to 20% just before the DEJ. Compared to human enamel, the Alouatta enamel showed similar microstructures, chemical constituents, and magnitudes of mechanical properties, but showed less variation in hardness and Young's modulus, despite the very different diet of this species. Am J Phys Anthropol 141:7-15, 2010. (C) 2009 Wiley-Liss, Inc.