Dental Caries (Tooth Decay)

Dental caries (tooth decay) is a major oral health problem in most industrialized countries, affecting 60–90% of schoolchildren and the vast majority of adults.

The early manifestation of the caries process is a small patch of demineralised (softened) enamel at the tooth surface, often hidden from sight in the fissures (grooves) of teeth or in between the teeth. The destruction spreads into the softer, sensitive part of the tooth beneath the enamel (dentine). The weakened enamel then collapses to form a cavity and the tooth is progressively destroyed. Caries can also attack the roots of teeth should they become exposed by gum recession. This is more common in older adults.

Dental caries is caused by the action of acids on the enamel surface. The acid is produced when sugars (mainly sucrose) in foods or drinks react with bacteria present in the dental biofilm (plaque) on the tooth surface. The acid produced leads to a loss of calcium and phosphate from the enamel; this process is called demineralisation.

Reduce Frequent Consumption of Sugars


There is overwhelming evidence that frequent consumption of sugars is associated with caries. Dietary advice should be aimed at limiting the frequency of sugar intake. Studies have shown that sugar consumption remains a moderate risk factor for caries even when populations have adequate exposure to fluoride, and that exposure to fluoride coupled with a reduction of sugar intake has an additive effect on caries reduction. In a comparison of food habits in children and adolescents in 35 countries and regions covering Europe, Israel  and North America, Ireland ranked as having the highest average weekly frequency of sweets consumption.

Foods and drinks containing “free sugars” (i.e., sugars which have been added to food plus sugars naturally present in honey, fruit juices and syrup) should be recognised and the frequency of their intake – especially between meals – reduced. As shown in the Stephan curves opposite, the intake of sugar between meals increases the periods of time plaque pH dips below the critical level of 5.5. When plaque pH is lower than 5.5,  remineralisation occurs. Subjecting teeth to frequent bouts of demineralisation allows less time for their remineralisation; thus, teeth become more susceptible to decay. Detailed  advice on nutrition and oral health is given here

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