Overview

It has been established that the oral environment is one of the primary factors in the caries process. Only when acidity increases in the oral environment does demineralization of enamel, and subsequently caries, occur. In this section, the role of fermentable carbohydrates is discussed, paying particular attention to how caries can be influenced by the cariogenic potential of ingested sugars and starches, the physical traits of ingested carbohydrates (such as their adhesiveness), and the frequency of intake and exposure to sugars. The Stephan curve, which illustrates the dental pH changes over time in response to a carbohydrate challenge, is also introduced, with a discussion of how factors such as the type of carbohydrate, the buffering capacity of bacteria, and the type and amount of bacteria present in plaque affect dental plaque pH responses.

Clinical Significance Snapshots

Which environmental factors can easily be modified to aid in prevention of dental caries?

Some factors are much easier to modify than others. The consumption of sugars (as Fermentable carbohydrates) is largely discretionary and therefore can be controlled by the patient. Many foods and beverages have sugar-free forms and can easily be substituted in the daily routine. Likewise, the addition of ‘table sugar’ to meal items such as cereals and hot drinks should be limited and avoided altogether or substituted by non-cariogenic sugar alternatives when possible. Not only should the amount of sugar be limited, but the Stephan curve tells us the frequency should be reduced wherever possible. So, a patient at risk of developing new carious lesions should restrict all exposure to sugars to mealtimes only.

The dental plaque biofilm should be controlled as much as possible by frequent and thorough oral hygiene. As it is simply not possible to remove all acidogenic / cariogenic bacteria from the mouth with conventional oral hygiene, it is not surprising that there are few studies showing any correlation between oral hygiene and the prevention of dental caries.

If demineralization is unavoidable, then the environment can be modified to encourage remineralization. Saliva is the key remineralizing agent, as it is supersaturated with respect to calcium and has good buffering capacity. Saliva production can be stimulated by chewing sugar-free gum. The increase in the flow of saliva also helps to reduce the clearance time, reducing the length of exposure of cariogenic substances in the oral cavity.

How can I work with my patient in modifying the environmental factors to reduce the risk of developing dental caries?

If a patient or other family members have signs of caries, it is critically important to look for environmental factors that may be contributing to increased risk of developing the disease. Changing environmental factors is always a challenge, and success is more likely if the family unit’s environment is investigated as well as that of the specific at-risk individual family member. Changing the environmental factors of only one family member is unlikely to succeed.

Fermentable carbohydrates (especially the mono- and disaccharides of glucose and sucrose) are the most important causative factor to change. Eating and drinking habits should be investigated—ideally through a 3- or 4- day diet diary that lists all eating and drinking occasions—to assess the amount and frequency of exposure. Between-meal episodes should be reduced wherever possible, and sugar substitutes should be used. Sugars as part of a meal should be reduced, and fruits or vegetables, or a sugar substitute, could be used instead of many sugar-containing foods. If obesity is present in the family, referral to a dietitian/nutritionist may be very beneficial for all.

The dental plaque biofilm should be controlled as much as possible through frequent and thorough oral hygiene. As it is simply not possible to remove all acidogenic / cariogenic bacteria from the mouth with conventional oral hygiene, it is not surprising that there are few studies showing any correlation between oral hygiene and the prevention of dental caries.

If demineralization is unavoidable, then the environment can be modified to encourage remineralization. Saliva is the key remineralizing agent, as it is supersaturated with respect to calcium and has good buffering capacity. Saliva production can be stimulated by chewing sugar-free gum. The increase in the flow of saliva also helps to reduce the clearance time, reducing the length of exposure of cariogenic substances in the oral cavity.