Tooth decay (dental caries): A Shift of Focus in Oral Health

A Shift of Focus in Oral Health The incidence of tooth decay (dental caries) in children and adolescents in most European countries has fallen steadily over the past three decades, despite the fact that the average intake of sugars has remained fairly constant.

So which factors are responsible for this positive trend?

It appears that better oral hygiene (more tooth brushing and the use of dental floss) and fluoride can take the credit.

Tooth decay Tooth decay occurs when several factors occur simultaneously. Firstly, there must be a tooth that is susceptible to decay.

Secondly, there must be dental plaque i.e. bacteria that ferment carbohydrates to produce acids, that in turn erode the tooth enamel and 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 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 often food is eaten, the more often the bacteria have an opportunity to ferment carbohydrates.

Saliva plays a role too by neutralising acid, providing the minerals for remineralisation and helping to clear food from the mouth more quickly.

Dietary factors The effect of diet on the development of dental caries is not as clear-cut as many people believe.

While a relationship between carbohydrate intake and tooth decay has been clearly demonstrated, the direct link between intake of sugar and dental decay is now weak in most European countries.

Many people for example consume relatively large amounts of sugars on a regular basis and yet have little tooth decay.

A Dutch study found that the time 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 tended to cling on and around 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 also changed. It is now known that many other 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 health 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 flouridated toothpastes, have lessened the importance of diet in tooth decay.

However, in countries where flouridated 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 a fluoride content between 0.05-14 ppm. Fluoride is ubiquitous in foodstuffs; the richest sources are tea and marine fish that are consumed with their bones (e.g. anchovies). Preventing tooth decay Good oral hygiene and the use of fluoride are now considered to be the main factors in preventing tooth decay. The following tips provide further advice for helping to keep teeth caries-free.

Begin dental care early – 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, formula, juice or sweetened beverage.

The sugars remain on the teeth for long periods of time and can lead to "baby bottle tooth decay".

* Clean teeth 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 been 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 food or sip drinks continuously.

* Advice on diet should be based on good dietary practices consistent with advice on general healthy eating.

References * Van Loveren C., Diet and Dental Caries: cariogenicity may depend more on oral hygiene using fluorides than on diet or type of carbohydrates. Eur. J. Paed. Dentistry, June 2000, 1 (2) * Nutrition, Diet and Oral Health for the 21st Century. Inter Dental J., 6/01, Suppl. * Konig, KG. Diet and Oral Health. Inter. Dental J., 2000, 50, 162-174

WHAT TYPES OF CARBOHYDRATES MAY LEAD TO TOOTH DECAY? The "Extrinsic" and "Intrinsic" sugars debate Many people are confused about the types of carbohydrates that have the potential to be fermented by bacteria to cause tooth decay. Some scientists have further complicated the picture by dividingsugars into "intrinsic" and "extrinsic" sugars. Intrinsic sugars are those present naturally within the cellular structure of food, that is, mainly in fruits and vegetables.

Extrinsic sugars are those which are free in food or added to it. This group is further divided into milk sugars (lactose) and non-milk extrinsic sugars, that is fruit juices, honey, added sugars. Studies show that bacteria can ferment both intrinsic and extrinsic sugars so all carbohydrate-containing foods have the potential to contribute to tooth decay. A healthy, enjoyable diet coupled with good oral hygiene is the best way to protect teeth and promote overall good health.

References: European Food Information Council (EUFIC) Date last updated: 22 November 2006