The enamel is made of closely packed mineral crystals. Every day minerals are lost and gained from inside the enamel crystals through processes called demineralization and remineralization, respectively.

Demineralization occurs when the enamel crystals and the spaces between them are dissolved by acids, formed by the combination of plaque bacteria and sugar in your mouth. The process is balanced by remineralization, in which minerals such as fluoride, calcium and phosphate are deposited inside the enamel. Too much demineralization without enough remineralization to repair the enamel leads to tooth decay.