Demineralization is a physicochemical process of dissolution of hydroxyapatite crystals by bacterial acids.

Both demineralization and remineralization occur on the tooth surface, and thus can be considered as highly dynamic processes, characterized by the flow of calcium and phosphate out of and back into the tooth enamel. Fluoride promotes remineralization and this has been suggested as the main mechanism by which fluoride protects the teeth. The essence of the remineralization concept of demineralized tooth surfaces might be achieved by simultaneously supplying calcium, phosphate, and fluoride ions to the teeth in order to induce formation of various apatites that remineralize and strengthen the tooth. Therefore, intensive investigations on the remineralizing potential of new toothpastes and fluid formulations based on nanotechnology are in progress.