[Caries-- changing patterns].

This article briefly describes the pathogenesis of dental caries. It focuses on the relevant chemical processes and histological changes in dental enamel. Recent studies have shown that the mineral balance at the tooth-oral fluid interface are determinants for the occurrence of caries, and more important than the intrinsic tissue properties. During periods of low pH, following bacterial metabolism of fermentable carbohydrates, enamel is demineralized. However, loss of tissue may be compensated by mineral deposition from saliva during subsequent periods at neutral pH ('remineralization'). The mineral balance is positively affected by the presence of low fluoride levels in the oral fluids. Clinically this becomes manifest in the decreasing rates of caries initiation and progression. Also it may affect the appearance of incipient enamel lesions, which in turn could complicate caries diagnosis. The changing patterns of dental changes thus have implications for procedures in preventive and restorative practise.