Micro-organisms live in the oral cavity. They feed on substances that are easily broken down – above all sugar. In doing so, they excrete metabolic products (acids), which attack and decalcify the enamel. As a result, there first appears, under the still intact enamel surface, a decalcified area (chalky spots/initial lesion). If the decalcification continues, the enamel surface is breached and a cavity, ‘caries’, appears.
