TOOTH decay occurs when several factors coincide. First, there must be a tooth that is susceptible to decay. Second, there must be dental plaque, i.e. bacteria that ferment carbohydrates to produce acids that erode the tooth enamel. Finally, carbohydrates must be present to be fermented by the bacteria. In addition, there has to be sufficient time for demineralisation (dissolution of the tooth enamel) to occur and insufficient time for the body’s natural defence mechanism that remineralises the tooth to repair the damage.
Each of these three factors is, in turn, affected by other factors. For example, the presence of fluoride aids remineralisation and alters the tooth structure. The net effect is that a tooth surface is less vulnerable to decay. The frequency of eating is also important because the more the food is eaten, the more often the bacteria have an opportunity to ferment carbohydrates. Saliva also plays a role by neutralising acid, providing the minerals for remineralisation and helping clear food in the mouth more quickly. So, the more saliva produced in the mouth, the less the chance of tooth decay.
The effect of diet on developing dental caries is not as clear-cut as many believe. While a relationship between carbohydrate intake and tooth decay has been clearly demonstrated, the direct link between sugar intake and dental decay is now weak in most European countries. Many people, for example, consume relatively large amounts of sugars regularly and yet have little tooth decay.
A Dutch study found that the time the food is retained in and around the mouth is more important for tooth decay than the sugar content of the foods. The researchers compared sugar solutions to meals plus snacks and found that carbohydrate foods that tend to cling on and around the teeth were more likely to cause tooth decay than sugar solutions. These foods are not necessarily those we think are “sticky”. For example, toffee melts and clears from the mouth quickly compared to some starch-containing foods.
The major emphasis on sugar and sugar-containing foods as being implicated in tooth decay has changed. It is now known that many carbohydrate-containing foods that
were traditionally believed to be tooth-friendly, such as bread, have the potential to contribute to tooth decay. For example, starchy foods such as bread lead to the production of acid by plaque bacteria, and all fruit has the potential to cause tooth decay, yet we should continue to eat these foods for pleasure and because of their benefits.
Scientists now believe that the role of diet in dental caries appears to be less related to the diet itself and more to individual behaviours. Good oral hygiene and fluoride particularly applied topically by fluoride toothpaste, have lessened the importance of diet in tooth decay. However, in countries where fluoridated toothpaste is not widely available, frequent intake of carbohydrate-containing foods is still an important factor in tooth decay.
The major source of dietary fluoride is drinking water with fluoride content. Fluoride is ubiquitous in foodstuffs; tea and marine fish are the richest sources. Good oral hygiene and the use of fluoride are now considered to be the main factors in preventing tooth decay. The following tips provide advice for helping to keep teeth caries free.
Begin dental care early, and start brushing teeth as soon as the first baby teeth erupt. Do not make it a habit for infants to go to sleep while drinking from a bottle of milk, juice or sweetened beverage. The sugars remain on the teeth for long periods and can lead to baby bottle tooth decay. Clean with fluoride toothpaste twice daily and clean around the teeth with dental floss or toothpicks once a day. Do not eat after cleaning teeth at bedtime as salivary flow decreases as we sleep. Sugar-free chewing gum has shown to be tooth-friendly as it helps increase saliva flow and clears food debris from the mouth. How often you eat and drink counts. Allow time between eating occasions for saliva to neutralise the acids. Do not nibble the food or sip drinks continuously. Advice on diet should be based on good dietary practices consistent with advice on general healthy eating.