Dental Caries and Diet

Role of Diet

• Diet plays a central role in the development of dental caries
• Dietary sugars are the major dietary factor affecting dental caries prevalence and progression
• Sucrose is the most cariogenic sugar because it produces acid and is utilized by Mutans streptococci to produce extracellular polysaccharide glucan
• Glucan polymers enable Mutans streptococci to adhere firmly to teeth

Caries Mechanism

• Acidogenic bacteria ferment CHO, producing organic acids that diffuse into enamel, dentine, or cementum, and partially dissolve the carbonated hydroxyapatite mineral crystals
• If the process continues, minerals (calcium and phosphate) diffuse out of the tooth, leading to cavitation
• Demineralization can be reversed by calcium and phosphate, together with fluoride, diffusing into the tooth and depositing a new layer on the crystal remnants in the non-cavitated lesion
• This new mineral crystal layer is more resistant to acid compared with original hydroxyapatite mineral

Dietary Factors and Dental Caries

• Frequency and amount of ingestion of dietary sugars are important in the etiology of caries
• Food form influences the duration of exposure and retention of the food on the teeth
• Oral clearance is affected by retentive properties of food, such as cookies and chips, which increase the potential for starch to break down into sugars and contribute to the caries process
• Sugar alcohol-based products, such as sorbitol, xylitol, mannitol, erythritol, and isomalt, stimulate saliva, increase the clearance of sugars and other fermentable CHO, and increase the buffering capacity

Protective Factors and Dental Caries

• Cheese has anti-cariogenic properties, stimulating salivary secretion, increasing plaque calcium concentration, and adsorbing protein (casein) on the enamel surface
• Milk contains lactose, which may be classified as cariogenic, but is the least cariogenic of dietary sugars, and also contains calcium, phosphorus, and casein, which inhibit caries
• Fibrous foods mechanically stimulate salivary flow
• Fat reduces cariogenicity of food, forms protective barriers on the enamel, surrounds carbohydrates making them less available, and speeds up their removal from the mouth
• Black tea contains fluoride, increasing plaque fluoride concentration and reducing the cariogenicity of a sugar-rich diet