All solid and liquid foods containing carbohydrates bio-available to bacteria are potentially cariogenic. Acid-forming bacteria, such as Streptococcus mutans, begin the immediate breakdown of sucrose from food, potentially contributing to dental caries.
Sugars on the tooth surfaces are converted to acid within seconds of ingestion. The acid acts to demineralize the tooth. Left undisturbed, the acid produced from the ingestion of a sugar can remain in the oral cavity up to 2 hours. During this acid attack, the pH level of plaque may drop from a normal range of 6.2-7.0 down to a pH of 5.2-5.5, the level at which demineralization can occur.
Consumption of caries-producing solid and liquid foods will lower the oral pH to a level that makes the enamel susceptible to caries. These frequent exposures can lower the pH to demineralizing levels for several hours per day.
The texture of foods, likewise, influences the length of time demineralization can occur. Foods that are more retentive and slower to dissolve will remain on the tooth surface for a longer time. Sticky, retentive snacks and slow dissolving carbohydrates, such as raisins, dried fruit, fruit rolls, bananas, caramels, jelly beans, or peanut butter and jelly sandwiches can lead to caries when consumed on a regular basis. Less retentive foods such as raw crisp fruits (apples, for example) and raw vegetables stimulate saliva flow while also mechanically removing plaque.
In order to eliminate or reduce caries risk in their infant or young child, caregivers should understand the relationship between diet and dietary habits and dental caries. After the eruption of the first primary tooth, prevention of caries is possible by restricting bottle/breast feeding to normal meal times. The caregiver should be advised to establish a pattern of three regular meals a day. In between-meal snacks should be limited and be foods of high nutrient density with low cariogenicity, such as meats, eggs, cheese, raw vegetables, fresh or water packed fruit, popcorn, and nuts.