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 saliva, 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 the prevention of 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. While modifying environmental factors is always a challenge, 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.

Although some factors are easier to modify than others, there are some things that can be done without too much effort that may have a significant impact toward the prevention of caries. These include: a) alteration in the consumption of sugars (as fermentable carbohydrates) to minimize the potential for demineralization; b) controlling the dental plaque biofilm to reduce the quantity of cariogenic bacteria present (although there are few studies showing direct correlations between oral hygiene and the prevention of dental caries, likely due to the fact that it is impossible to remove all of the acidogenic/cariogenic bacteria present in the mouth, it makes sense to try to minimize the overall challenge as much as possible); and c) the encouragement of remineralization processes to maximize the potential for mineral repair.

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

After making an overall assessment of the caries status of each patient, positive environmental changes can be suggested that will help reduce the risk of caries by minimizing negative factors and encouraging positive ones.

  1. Ingestion of fermentable carbohydrates (especially the mono- and disaccharides of glucose and sucrose) is 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.
    • Sugars as part of a meal should be reduced whenever possible, and increased consumption of fruits and vegetables can be suggested as alternatives to sugar-containing foods.
    • The use of sugar substitutes should be encouraged.
    • Between-meal episodes should be minimized.
    • If obesity is present in the family, referral to a dietitian/nutritionist may be very beneficial for all.
  2. Control the dental plaque biofilm to regularly remove as many acidogenic / cariogenic bacteria from the mouth as possible.
    • Encourage frequent and thorough oral hygiene practices, including twice-daily brushing with fluoride-containing toothpaste, regular flossing and the use of fluoride- containing or antibacterial mouthrinses where warranted.
  3. Modify the oral environment to enhance the potential for remineralization.
    • Encourage the use of sugar-free chewing gum to stimulate the production of saliva.
      • Saliva is the key remineralizing agent, as it is supersaturated with respect to calcium and phosphate, and it has good buffering capacity.
      • Increasing the flow of saliva helps to decrease clearance time, reducing the length exposure to cariogenic substances in the oral cavity.