Studies on the calcification mechanism of enamel using ion-selective membrane and glass fiber

离子选择膜和玻璃纤维研究牙釉质钙化机制

• 批准号: 61570871
• 负责人: MORIWAKI Yutaka
• 金额: $ 1.28万
• 依托单位: Asahi University School of Dentistry
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61570871/
• 关键词: Calcification; Enmel apatite; Apatite synthesis; Hydroxyapatite; Octacalcium phosphate; Crystal nucleation; Crystal growth

Cation-delective membrtance were used as a model cell for tissue cell to get better understanding of calcification mechanism in tooth enamel. Our previous in vitro finding has suggested that hydroxyapatite obtained by hydrolysis of octacalcium phoshate that nucleated on and grew perpendicular to the cation-selective membrane id comparable to human enamel in respect to crystal shape,crystallinity and the degree od orientation.In this report,the influenece of pH and initial concentrations of calcium,phosphate, carbonate,magnesium and fluoride ions on the morphology and orientation of octacalcium phosphate is stafued in the cation-selective membrane system and glass-fiber system to elecidate the calcification mecanism and growrh process in enamel. In order to clarify the reaction that might ge taking place in the diffusion layer on the cation-selective membrane, some reactions were carried out in non-membrane sytem in which precipitation was initiated by adding calcium solution fropwise t … More o phosphate solution. In the membrane system, initial precipitated on the membrane appeared granular in shape and the incresed in size to from a co-agulated granular form, resulting in a creat-like appeatanece. With time, however, they grew outbawd prefetentially perpenficular to the membrance, of which X-tby diffraction pattern was characteristic of oriented OCP.In the non-membrance system, the first precipitation took place when the solution saturtation was slightly undersaturated with respect to reported value of ACP solubility product. Interesting point was that when continued the Ca addition the degree of solution saturation moved alog almost parallel to the solubility line of OCP the chemical potential plot. But, once the Ca addition ceased OCP convert to hydroxyapatite. From these in vitro findings it may behypothsized that in enemel formation feeding rate of Ca^<2+> to mineralixaing fornt is modetrately greater enough to stabilize fibbon-kike COP and enemel prisms might be formwd. %on the contray, in the calcification of bone and dentine the Ca^<24> feeding rate may bre consiferably smaller. Less

为了更好地了解牙釉质钙化的机制，我们采用了阳离子选择性膜作为组织细胞的模型细胞。我们以前的体外研究结果表明，由磷酸八钙水解得到的羟基磷灰石在阳离子选择性膜上成核并垂直于膜生长，在晶体形状、结晶度和取向度方面与人牙釉质相当。本研究通过在阳离子选择性膜系统和玻璃纤维系统中观察镁离子和氟离子对磷酸八钙形态和取向的影响，探讨了钙在牙釉质中的形成机制和生长过程。为了弄清在阳离子选择膜上扩散层可能发生的反应，在非膜体系中进行了一些反应，在该体系中，通过向膜中逐层加入钙溶液引发沉淀， ...更多信息 o磷酸盐溶液。在膜系统中，膜上的初始沉淀物呈颗粒状，随着沉淀物尺寸的增大，形成共凝聚的颗粒状沉淀物，形成膏状外观。在非膜体系中，当溶液饱和度相对于文献报道的ACP溶度积值稍欠饱和时，第一次沉淀发生。有趣的是，当继续添加Ca时，溶液的饱和度移动了约10%，几乎平行于化学势图中OCP的溶解度线。但是，一旦停止添加Ca，OCP就转化为羟基磷灰石。根据这些体外研究结果，可以推测，在敌人形成中，Ca^<2+>对矿物质的供给率非常大，足以稳定纤维状COP，并且可能形成敌人棱镜。%，而在钙化的骨和牙本质中，钙的<24>供给率可能会相当小。少