Nature and Role of Loosely Bound Fluoride in Dental Caries
Nature and Role of Loosely Bound Fluoride in Dental Caries
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松散结合氟化物的性质和在龋齿中的作用
DOI：
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
J. Christoffersen
中科院分区：
文献类型：
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作者：
J. Arends;J. Christoffersen
本文讨论了松散结合氟及其在龋病和预防中的作用。松散结合的氟化物(简写为氟化物是否吸附在釉质矿物微晶上。最近的几项研究表明，牙釉质中总氟化物水平较高并不能保证预防龋齿。这导致的结论是，固体牙釉质中的大部分氟化物在预防方面并不活跃。描述了在酸性条件下Fa在矿物上的吸附。溶液中的氟化物与晶面吸附的Fa之间很可能存在动态平衡。当微晶被吸附的Fa完全覆盖时，对溶解的抑制作用最大。矿物的溶解速度取决于pH值，与微晶接触的液体中钙和磷的实际浓度，以及被吸附的氟化物覆盖的表面的比例。位于微晶内部的氟化物FS相对不重要。根据不同的条件，在釉质表面和釉质中可以形成“类CaF2”材料。体内形成的球状类CaF2物质不是纯CaF2，溶解时会释放F~+，这些离子也会以Fa的形式部分吸附在牙釉质中和牙釉质上。目前，来自体内形成的类CaF2材料的Fa的数量和重要性尚不清楚。体外强抑制牙釉质脱矿所需的氟化物水平Fa，估计相当于1ppm或50μ/L氟离子溶液中的氟离子浓度FL。体内所需的浓度FL可以实质上更大，而F具有最大值，约为2μ/m2，对应于微晶表面中的羟基位置的浓度。这篇论文指出，经常使用低水平的氟化物很可能比使用高氟浓度的溶液进行少量治疗更有利于预防龋病。
This paper discusses loosely bound fluoride and its role in dental caries and prevention. Loosely bound fluoride (abbr. by F) is fluoride adsorbed onto enamel mineral crystallites. Several recent studies indicate that a high total level of fluoride in enamel does not guarantee protection against caries. This leads to the conclusion that a major part of fluoride present in the solid enamel is not active in prevention. The adsorption of Fa to the mineral under acidic conditions is described. Most likely there is a dynamic equilibrium between fluoride in solution and adsorbed Fa at the crystal surface interface. When the crystallite is completely covered by adsorbed Fa, there is a maximum inhibition of dissolution. The rate of dissolution of mineral depends on pH, the actual concentrations of calcium and phosphate in the liquid in contact with the crystallites, and on the fraction of the surface covered by adsorbed fluoride. The fluoride, Fs, localized in the inner part of the crystallites is relatively unimportant. “CaF2-like” material can be formed on and in enamel depending on conditions. The in vivo-formed globular “CaF2-like” material is not pure CaF2 and releases F~ ions when dissolving; these ions will also be partly adsorbed as Fa in and on enamel. Presently, the amount and importance of Fa originating from in vivo-formed “CaF2-like” material are not known. The level of fluoride, Fa, necessary for strong inhibition of enamel demineralization in vitro is estimated to correspond to a fluoride concentration, FL, in the liquid phase of 1 ppm or 50 μmol/L fluoride ions. The concentration, FL, needed in vivo may be substantially greater, whereas F, has a maximum value, of the order 2 μmol/m2, corresponding to the concentration of hydroxyl sites in the surface of the crystallites. The present paper indicates that frequent low-level applications of fluoride are most likely more beneficial in caries prevention than few treatments with solutions having a high fluoride concentration.