Physicochemical Requirements for Rapid Remineralization of Early Carious Lesions

Abstract

Physicochemical data related to remineralization of carious lesions were determined. Diffusion properties of Ca ions, fluoride ions, calcium-anion complexes, and cation-fluoride complexes were studied using protein-impregnated and protein-apatite-impregnated membranes. Stability constants of metal-fluoride and amine-fluoride complexes were determined by titration. Artificial carious lesions were produced in human enamel and immersed in remineralizing solutions containing Ca, Zn, Sr, phosphate, acid anions, fluoride and organic cations at various pH levels. Selected samples were reimmersed in demineralizing solution. Sodium fluoride, acidulated phosphate-fluoride and calcium-phosphate fluoride solutions were tested similarly. Calcium-anion complexes diffused rapidly through protein gels. Metal-fluoride complexes were generally too weak to affect diffusion rates but some cations enhanced fluoride transport. Partial remineralization of lesions occurred with the new test solutions more rapidly than with traditional fluoride preparations and further demineralization was markedly reduced. Remineralizing solutions based on this new hypothesis show promise as an improved caries preventive measure.