CARBONATO APATITE FORMATION IN ENAMEL MINERALIZATION

不同于钙和钙的无机成分 牙釉质液体中的磷、碳酸盐含量似乎足够高 在釉质形成过程中影响矿化过程。 碳酸盐被大量地加入到 釉质晶体的晶格；这种结合 导致缺陷，这些缺陷的作用是 脱矿或龋齿形成。目前的建议是， 旨在阐明碳酸盐磷灰石的形成机制 釉质发生过程中的形成及其化学性质 釉质矿物，包括以下几个方面： 1)牙釉质的溶解度和溶解度积的测定 在特定发育阶段分离的磷灰石 成釉作用。牙釉质样本将从 小猪的恒牙。矿物质在水中的平衡 酸性溶液将在二氧化碳的部分压力下进行 与牙釉质液体中的相似。的分析结果 平衡解决方案将用于测试几个模型 关于碳酸盐的化学计量和类型 釉质晶体晶格中的取代。 2)指定碳酸盐离子的位置(吸附到 釉质磷灰石和/或在PO4或OH位上的取代 晶格)。特别关注的将是碳酸盐 与最初形成的晶体有关。建议数 方法将结合化学、IR、EM和离子层析 技巧。 3)牙釉质基质蛋白吸附性能的研究 碳酸磷灰石。一批批的吸附剂将在#年制备。 水相体系，并根据化学性质进行表征 组成、碳酸盐取代、比表面积和 晶体形态。这些吸附物将从以下物质中获得 分泌型猪釉。吸附剂-吸附剂平衡 将在部分二氧化碳压力的溶液中进行 离子强度与釉质液体的离子强度相似。 4)碳酸盐掺入土壤的可能机制 形成釉质磷灰石。将进行实验 使用合成的碳酸磷灰石，如在过饱和状态下所见 成分与釉质液体相似的溶液。 拟议的研究将提供有关 釉质晶体的发育成熟，形成 晶体缺陷，以及相关生物的影响 牙釉质参数对牙釉质稳定性的影响 成龋性环境。

Of the inorganic constituents different from calcium and phosphorus, carbonate in the enamel fluid seems to be high enough to affect the mineralization process during amelogenesis. Carbonate is incorporated in substantial amounts into the crystalline lattice of the enamel crystals; this incorporation results in defects which function as reactive sites for demineralization or caries formation. The present proposal, intends to elucidate the mechanisms of carbonato apatite formation during amelogenesis and the chemical properties of enamel mineral, includes the following aspects: 1) Determination of the solubility and solubility product of enamel apatites separated at specific developmental stages of amelogenesis. The enamel samples will be obtained from the permanent dentitions of piglets. Equilibration of the mineral in acidic solutions will be conducted under partial pressures of CO2 similar to those in the enamel fluid. The analytical results of the equilibrating solutions will be used to test several models with respect to the stoichiometry and the type of the carbonate substitution in the lattice of the enamel crystals. 2) Assignment of the location of carbonate ions (adsorption onto enamel apatites and/or substitutions in the PO4 or OH sites of the lattice). Special interest will be focused on the carbonate associated with the initially forming crystals. The proposed approach will combine chemical, IR, EM, and ion chromatography techniques. 3) Investigation of adsorption of enamel matrix proteins onto carbonato apatites. Batches of the adsorbents will be prepared in aqueous systems and characterized with respect to chemical composition, carbonate substitution, specific surface area and crystal morphology. The adsorbates will be obtained from secretory porcine enamel. Adsorbate-adsorbent equilibrations will be conducted in solutions having partial CO2 pressures and ionic strength similar to those of enamel fluid. 4) The possible mechanism of carbonate incorporation into the forming enamel apatite. The experimentation will be conducted using synthesized carbonato apatites as seen in supersaturated solutions having similar composition to that of enamel fluid. The proposed research will give basic information about the developmental maturation of enamel crystals, the formation of crystal defects, and the effect that pertinent biological parameters have on the stability of dental enamel in normal and cariogenic environments.