Pathogenesis
Cariogenic bacteria metabolize fermentable carbohydrates to produce organic acids, primarily lactic acid, which lower the pH of dental plaque below the critical pH of 5.5.
At this pH, hydroxyapatite dissolves, releasing calcium and phosphate ions from enamel in a process called demineralization.
Remineralization occurs when pH returns to neutral, allowing calcium, phosphate, and fluoride ions to redeposit into enamel. Fluoride promotes the formation of fluorapatite, which is more resistant to acid attack.
Net mineral loss occurs when demineralization episodes exceed remineralization, initially creating a subsurface lesion (white spot lesion) that can progress to cavitation.