QUANTITATION OF ENAMEL DEMINERALIZATION MECHANISMS

描述(改编自《调查者摘要》)：长期 拟议研究的目标是更好地了解 探讨龋病发生机制，为改进提供合理依据 预防或治疗方案。首席调查员建议做 碳化磷灰石反常溶解行为的基础研究 (CAPS)和人牙釉质(HE)，总的目标是建立 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。研究将在很大程度上依赖于亚稳态平衡。 溶解度(MES)分布范式和表面络合物假说 在上一个项目期开始之前开发的。MES和 表面上的复杂概念已经决定了对这两个问题的全新方法 实验设计和数据解释，并为 了解矿物组成、矿物组成和矿物之间的相互关系 生物矿物的结晶度、溶液组成和观察到的溶解度 和人造磷灰石。有四个具体目标。目标1建议进行以下研究 为上限建立数量级之间的定量关系 MES、CAP结晶度(特别是微晶应变)，以及 碳酸盐含量和MES支配表面络合物的化学计量比。 在目标2中，建议进行研究，以定量地确定 溶液中外来离子(锶和氟化物)对MES和 MES主控表面络合物的化学计量比。在目标3中，研究是 提出了定量地建立可能的晶格效应 这些外来离子对MES的影响很大。目标4建议建立 CAP研究结果与溶解度行为的相关性(上) 他的名字。过去项目期的两个主要试验性突破使 有可能实现这些目标。其中第一个步骤是 推导溶解驱动力函数的精度较高 (因此MES控制面的化学计量比完整)来自 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、溶液公共离子和溶液 外来离子)。另一种是分离和量化 微晶尺寸和微观应变对CAP结晶度的贡献 X射线衍射数据与Rietveld全谱拟合法 结构--细化。这两种方法结合在一起，允许解决 与每个特定目标相关的问题。

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.