Demineralization: 

Bacteria in our mouth uses carbohydrates from the foods we eat to produce acid. The acid then attacks our enamel rendering it weak, soft and more prone to cavities. This process is known as demineralization. 

Remineralization: 

Saliva has certain minerals that help harden or remineralize and strengthen our enamel. Saliva contains calcium and phosphate which are constantly working to help remineralize enamel.

Fluoride works by increasing the remineralization process

When there is an unequal balance and demineralization occurring faster than remineralization cavities occur. Fluoride counteracts the demineralization process and helps prevent cavities.

Fluoride treatment is recommended for kids, adults and the elderly. Caries can impact people of all ages, not just children. Anyone with high caries risk should regularly obtain professional fluoride treatments.