The science and practice of caries prevention

Background and Overview. Dental caries is a bacterially based disease. When it progresses, acid produced by bacterial action on dietary fermentable ca rbohydrates diffuses into the tooth and dissolves the carbonated hydroxyapa tite mineral-a process called demineralization. Pathological factors includ ing acidogenic bacteria (mutans streptococci and lactobacilli), salivary dy sfunction, and dietary carbohydrates are related to caries progression. Pro tective factors - which include salivary calcium, phosphate and proteins, s alivary flow, fluoride in saliva, and antibacterial components or agents-ca n balance, prevent or reverse dental caries. Conclusions. Caries progression or reversal is determined by the balance be tween protective and pathological factors. Fluoride, the key agent in battl ing caries, works primarily via topical mechanisms: inhibition of demineral ization, enhancement of remineralization and inhibition of bacterial enzyme s. Clinical Implications. Fluoride in drinking water and in fluoride-containin g products reduces caries via these topical mechanisms. Antibacterial thera py must be used to combat a high bacterial challenge. For practical caries management and prevention or reversal of dental caries, the sum of the prev entive factors must outweigh the pathological factors.