Three main factors must be simultaneously present for dental caries to occur:

1. microbial dental plaque (Streptococcus mutans and lactobacillus)
2. teeth susceptible to caries
3. frequent supply of fermentable carbohydrate

sugar + bacteria = acid
acid + tooth = cavity

Caries result from the action of organic acids, which are produced through the fermentation of carbohydrates by plaque micro-organisms. Acid production causes the plaque pH to fall, resulting in enamel demineralization and diffusion of calcium and phosphorus into the plaque.

Several factors affect the risk for dental caries:

1. The sugar content of a food.
2. The starch content of a food
3. How often a food is eaten throughout the day. Frequent snacking increases the risk of dental caries.
4. The sequence of foods eaten. High sugar foods eaten after a meal significantly decreases risk compared to eating them alone.
5. The combination of foods eaten. Cheese consumed with or immediately after ingestion of a sucrose solution or snack has been shown to limit the fall in plaque pH. Cheeses stimulate an abundant salivary flow, which helps to remove residual sugar from the mouth and neutralizes plaque acids. In addition, cheese promotes incorporation of high levels of calcium and phosphate into human dental plaque and reduces the amount of demineralization.
6. The amount of time the food remains in the mouth. Eating sticky or dry foods that remain on the teeth increase risk. Rinsing or brushing after eating significantly decreases risk.
7. The amount of saliva in the mouth. Saliva serves to dilute and buffer the acid. Individuals with a reduced saliva production are more prone to dental caries.

To prevent a cavity it is not necessary to eliminate all sugar from your diet. Nor is this a reasonable suggestion. However, you should decrease your sugar intake to a moderate, reasonable level. The most important factor is to try to only eat sugar with meals. Also, keep snacks to no more than 2-3 per day and choose foods that contain little or no sugar. It is preferable that snacks also contribute to good nutrition. The lists below indicate foods that contain sugar and therefore damage teeth if eaten as snacks. The next column lists foods that are safe for your teeth when used for snacking.

Not Suitable Snacks