Powder suspension method for critically re-examining the two-site model for hydroxyapatite dissolution kinetics.
Powder suspension method for critically re-examining the two-site model for hydroxyapatite dissolution kinetics.
复制标题
粉末悬浮法严格重新检查羟基磷灰石溶解动力学的双位点模型。
DOI：
10.1002/jps.2600730203
复制
发表时间：
1984
影响因子：
3.8
通讯作者：
Fox,JL
中科院分区：
文献类型：
--
作者：
Higuchi,WI;Cesar,EY;Cho,PW;Fox,JL
开发了一种粉末溶解方法，用羟基磷灰石悬浮液进行的实验证实了早先基于羟基磷灰石圆盘溶解的结论。虽然从本研究中获得的数据不可能对部位1的性质进行定量评估，但对羟基磷灰石溶解的两部位模型的部位2的性质和行为进行相当准确和独立的评价是可能的，并且结果清楚地验证了原始的两部位模型。本工作与早期的圆盘研究表明，从位2的溶解可用一级表达式Rate=KC2(Cs2-C)很好地描述，其中Kc2是一级速率常数，Cs2是位2的表观溶解度(由10Ca2+a6PO43−a2OH−的离子活度积Khap和溶液条件定义)，C是羟基磷灰石的微环境溶液浓度。对于四种不同的沉淀羟基磷灰石制剂，单一的KHAP值为1×10−128±1，与使用大范围部分饱和溶液和钙磷比溶液的实验结果一致。羟基磷灰石粉末和颗粒方法(包括数据评估程序)现在为研究与牙釉质溶解相关的复杂动力学和一般牙釉质化学提供了强有力的组合。
A powder dissolution method has been developed, and experiments with the hydroxyapatite suspensions confirm earlier conclusions based on dissolution from hydroxyapatite disks. Although a quantitative assessment of the properties of site 1 was not possible from the data obtained in the present study, a rather accurate and independent evaluation of the properties and the behavior of site 2 of the two‐site model for hydroxyapatite dissolution was possible, and the results clearly validate the original two‐site model. The present work together with the earlier disk studies show that dissolution from site 2 is well described by a first‐order expression, rate =kc2(Cs2‐C), wherekc2is a first‐order rate constant,Cs2is the apparent solubility for site 2 (defined by an ion activity product,KHAP, of the forma10Ca2+a6PO43−a2OH−, and the solution conditions), andCis the microenvironmental solution concentration of hydroxyapatite. For four different precipitated hydroxyapatite preparations, a singleKHAPvalue of 1 × 10−128± 1 was found to be consistent with experiments using solutions covering wide ranges of partial saturation and calcium‐phosphate ratios. The hydroxyapatite powder and pellet methods (including the data evaluation procedures) now offer a powerful combination for investigating the complex kinetics associated with dental enamel dissolution in particular and enamel chemistry in general.