Effect of Time and Degree of Saturation of Buffer Solutions on Artificial Carious Lesion Formation in Human Tooth Enamel

Publisher Website
Google Scholar
Abstract
The chemical systems to produce carious lesions described in the literature can be divided into three types: (a) gel systems, (b) systems containing a substance which decreases the dissolution rate of the mineral in the surface area of tooth enamel and (c) buffer systems containing calcium and phosphate. The third system can give essential information in the physicochemical sense, if in vivo conditions are simulated. This system was investigated in the present study. Artificial lesions were produced in the buccal surface of human premolars by applying buffers of pH 4 or 5 and which were undersaturated with respect to hydroxylapatite. Microradiographical tracings were taken from the sections and the following characteristics were studied: (a) the mineral content in the surface layer; (b) the mineral content of the body of the lesion; (c) and (d) the depth at which these mineral levels were reached, and (e) the depth of the lesion. It appeared that the mineral content in the surface layer decreased with decreasing degree of saturation and stabilized with time after an initial demineralization. The lowest mineral content of the body of the lesion decreased with decreasing degree of saturation and reached a final level close to zero. The speed with which the demineralization front progressed increased With decreasing degree of saturation of the buffer. The results are in agreement with the concept that the mineral in tooth enamel shows a gradient in its apparent solubility product with depth.