The Chemistry of Dental Erosion and Determination of Erosion Potential

Abstract

Dental erosion is caused by repeated short episodes of exposure to acids. Dental minerals are forms of hydroxyapatite containing impurity ions, which mostly increase solubility, so dentine or cementum mineral is more soluble than enamel mineral and all are more soluble than hydroxyapatite. Solubility is an important factor in erosion because it determines whether a solution is in equilibrium with the solid ('saturated') or is capable of dissolving or precipitating the solid ('undersaturated' or 'supersaturated'). In vitro, the dissolution rate is influenced by the degree of saturation of an erosive solution and also by other properties of the solution, such as pH, calcium concentration, buffering, fluoride and the presence of inhibitors. Furthermore, dissolution rate is influenced by the distinct structures of dentine and enamel, which modulate interactions between the tissue and the solution. Data on a wide range of beverages and other products, such as medications, indicate that the degree of saturation with respect to hydroxyapatite and fluorapatite contributes to erosivity, but that pH is probably the most useful single factor in predicting erosive potential. The role of buffering in erosive potential is not fully established and little is known of the role of naturally occurring inhibitors. Temperature, flow rate and dilution, as determined by the method of consumption of a product, are likely to have a strong influence on erosion in vivo. Prospects for prevention of erosion by product modification and for repair of erosive lesions by remineralization are reviewed.