QUANTITATION OF ENAMEL DEMINERALIZATION MECHANISMS

牙釉质脱矿机制的定量

• 批准号: 6691038
• 负责人: William I Higuchi
• 金额: $ 21.38万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 1982
• 资助国家: 美国
• 起止时间: 1982-11-01 至 2006-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6691038
• 关键词: X ray crystallography; acidity /alkalinity; apatites; calcification; calcium; carbonates; chemical kinetics; chemical synthesis; crystallization; dentin; fluoride ion; human tissue; hydroxyapatites; infrared spectrometry; minerals; precipitation; scanning electron microscopy; solubility; statistics /biometry; stoichiometry; strontium; temperature; tooth enamel

DESCRIPTION (Adapted from the Investigator's Abstract): The long term objectives of the proposed research are to gain a better understanding of the mechanisms of dental caries and to provide rational bases for improved preventive or therapeutic regimens. The Principal Investigator proposes to do basic studies of the anomalous solubility behavior of carbonated apatites (CAPs) and human dental enamel (HE) with the general objective of establishing how the solubility depends on the composition of the mineral phase, the crystallinity of the mineral phase, an the composition of the external dissolution medium. The studies will rely heavily on the metastable equilibrium solubility (MES) distribution paradigm and the surface complex hypothesis developed just prior to the beginning of the past project period. The MES and the surface complex concepts have dictated entirely new approaches to both experimental design and data interpretation and have provided the framework for understanding the interrelationship between mineral composition, mineral crystallinity, solution composition and the observed solubility of biominerals and synthetic apatites. There are four specific aims. Aim 1 proposes studies to establish for the CAPs the quantitative relationships between the magnitude of the MES, the CAP crystallinity (especially crystallite microstrain), and carbonate content, and the stoichiometry of the MES governing surface complex. In Aim 2, studies are proposed to quantitatively establish the influence of solution foreign ions (strontium and fluoride) on the magnitude of the MES and the stoichiometry of the MES governing surface complex. In Aim 3, studies are proposed to quantitatively establish the possible crystal lattice effects of these foreign ions on the magnitude of the MES. Aim 4 proposes to establish the relevance of the findings in the CAP studies (above) to the solubility behavior of HE. Two major experimental breakthroughs of the past project period make it possible for accomplishing these aims. The first of these is a procedure of relatively high accuracy for deducing the dissolution driving force function (and therefore the stoichiometry of the MES governing surface complete) from analysis of the MES distribution data obtained as a function of several independent variables (e.g., buffer pH, solution common ions, and solution foreign ions). The other is a procedure for separating and quantifying the contributions of crystallite size and microstrain to CAP crystallinity using X-ray diffraction data and the Rietveld method of whole-pattern-fitting structure-refinement. Taken together, these two methods permit addressing the questions associated with each of the Specific Aims.

描述（改编自研究者摘要）：长期 拟议研究的目标是更好地了解 为龋齿的发生机制提供合理依据 预防或治疗方案。首席研究员建议这样做 碳酸磷灰石异常溶解行为的基础研究 （CAP）和人类牙釉质（HE），总体目标是建立 溶解度如何取决于矿物相的组成， 矿物相的结晶度，以及外部的组成 溶解介质。这些研究将在很大程度上依赖于亚稳态平衡 溶解度（MES）分布范式和表面复合体假说 是在上一个项目期开始之前开发的。制造执行系统和 表面复杂的概念决定了两种全新的方法 实验设计和数据解释并提供了框架 了解矿物成分、矿物成分之间的相互关系 生物矿物质的结晶度、溶液组成和观察到的溶解度 和合成磷灰石。有四个具体目标。目标 1 建议研究 为 CAP 建立大小之间的定量关系 MES、CAP 结晶度（尤其是微晶微应变），以及 碳酸盐含量，以及 MES 控制表面复合物的化学计量。 在目标 2 中，建议进行研究以定量确定以下因素的影响： 溶液外来离子（锶和氟化物）对 MES 大小的影响 MES 控制表面复合物的化学计量。在目标 3 中，研究是 建议定量确定可能的晶格效应 这些外来离子对MES的影响程度。目标 4 建议建立 CAP 研究结果（上文）与溶解度行为的相关性 他的。近一个项目期间的两项重大实验突破使得 实现这些目标的可能性。其中第一个过程是 推导溶解驱动力函数的精度相对较高 （因此 MES 控制表面的化学计量完整） 分析作为几个函数获得的 MES 分布数据 自变量（例如缓冲液 pH、溶液常见离子和溶液 外来离子）。另一个是分离和量化的程序 微晶尺寸和微应变对 CAP 结晶度的贡献 X 射线衍射数据和全图案拟合的 Rietveld 方法 结构细化。综合起来，这两种方法可以解决 与每个具体目标相关的问题。