Correlating the Performance of Primate Enamel to Variations in its Chemistry, Structure and Properties

将灵长类动物牙釉质的性能与其化学、结构和性能的变化联系起来

• 批准号: 0749981
• 负责人: Timothy Weihs
• 金额: $ 7.5万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0749981&HistoricalAwards=false
• 关键词: Correlating; Performance; Primate; Enamel; Variations

Correlating the Performance of Primate Enamel to Variations in Its Chemistry, Structure and Properties NSF #0749981 T.P. Weihs and M.F. Teaford Johns Hopkins University Teeth are the most common elements in the human fossil record largely because they are the most resilient structures in the body. One of the major components of primate teeth is enamel, a composite made of hydroxyapatite crystals spun together in a complicated fashion forming what are known as prisms. The intricate details of enamel's development and morphology have provided a wealth of insights, ranging from permanent markers of developmental history to documentation of structural anisotropy of functional significance. However, what we know about enamel's structure also masks an incredible lack of knowledge about its physical properties. In fact, most people think of enamel as a homogeneous substance, like steel or water, with uniform properties. Yet, variations in chemistry, prism adhesion and microscopic porosities can lead to significant variations in the hardness and stiffness of enamel and hence its behavior during mastication. The purpose of this project is to document variations in the mechanical properties (hardness and stiffness) of enamel using nanoindentation techniques. These properties will then be correlated with changes in the chemistry and the microstructure of enamel in humans and other primates. Studies will be limited to extracted and museum molars (maxillary M1) for two species: modern humans and Macaca fascicularis. This will, in turn, allow us to perform a variety of comparisons, in addition to the basic comparisons of the enamel properties of maxillary M1 for extracted and museum teeth of both species. This research project will focus on comparisons of freshly-extracted teeth and museum teeth to verify the mechanical integrity of museum samples. This project will also examine questions of biomechanical significance e.g., do enamel properties differ on so-called functional and support cusps Are the teeth of older individuals stiffer than those of younger individuals A better understanding of the mechanical properties of enamel will yield a wealth of insights into dental function, dental clinical responses, paleobiology, and evolutionary theory.

将灵长类动物牙釉质的性能与其化学、结构和特性的变化相关联 NSF #0749981 T.P.魏斯和 M.F.约翰霍普金斯大学蒂福德大学牙齿是人类化石记录中最常见的元素，很大程度上是因为它们是体内最具弹性的结构。灵长类动物牙齿的主要成分之一是牙釉质，这是一种由羟基磷灰石晶体制成的复合材料，以复杂的方式旋转在一起，形成所谓的棱柱。牙釉质发育和形态的复杂细节提供了丰富的见解，从发育历史的永久标记到功能意义的结构各向异性的记录。然而，我们对牙釉质结构的了解也掩盖了对其物理特性的严重缺乏。事实上，大多数人认为珐琅是一种均质物质，就像钢或水一样，具有均匀的特性。然而，化学成分、棱柱粘附力和微观孔隙率的变化可能导致牙釉质的硬度和刚度发生显着变化，从而导致其在咀嚼过程中的行为发生显着变化。该项目的目的是使用纳米压痕技术记录牙釉质机械性能（硬度和刚度）的变化。这些特性将与人类和其他灵长类动物牙釉质的化学和微观结构的变化相关联。研究将仅限于两个物种的拔出和博物馆磨牙（上颌 M1）：现代人类和食蟹猴。除了对两个物种的拔牙和博物馆牙齿的上颌 M1 牙釉质特性进行基本比较之外，这将使我们能够进行各种比较。该研究项目将重点比较新拔出的牙齿和博物馆牙齿，以验证博物馆样本的机械完整性。该项目还将研究具有生物力学意义的问题，例如，牙釉质特性在所谓的功能和支撑牙尖上是否有所不同？老年人的牙齿是否比年轻人的牙齿更坚硬？更好地了解牙釉质的机械特性将产生对牙齿功能、牙科临床反应、古生物学和进化理论的丰富见解。