Strong stable acids do not break down easily, so very small quantities can keep on dissolving the minerals in your enamel. In the presence of these acids, millions, even billions, of calcium and other mineral ions are removed from the hydroxyapatite latticework. Eventually, the enamel loses its structural integrity. This natural mechanism is enhanced be eating unprocessed foods, rich in minerals, including trace minerals, such as natural and organic foods. Our bodies utilize carbon dioxide from our breath and water from our saliva to create a mild, unstable acid, carbonic acid.
Carbonic acid is the heart of the natural remineralization process.
Though natural remineralization is always taking place, the level of activity varies according to conditions in the mouth. Only a miniscule fraction of the carbon dioxide from the breath is converted to carbonic acid. When all this happens, a mineral ion is precipitated out of solution into the structure of the enamel. This also indicates that with a pre-modern diet, humans probably also had strong enamel naturally. For strong enamel in today's world, though, the natural remineralization process needs to be augmented.