Reversing the Caries Process

How prevalent is dental caries in the United States today?

It varies depending on the population group. For instance, the last national study was the National Health and Nutrition Examination Survey (NHANES) III.1 The survey shows a 59% decrease in the incidence of caries in the permanent teeth in children aged 6-18 between NHANES I, which covers 1971 through 1974, and NHANES III 1988-1994.1 However, the 2- to 5-year-old populations did not experience the same substantial decline. The decrease in caries in the 6-18 age group is so profound because of the increased exposure to fluoride during this time period.

Most clinicians use radiographs and explorers as the primary caries detection methods. Are there new approaches and devices for caries detection?

When caries was very prevalent in the United States back in the 1960s and 1970s, caries was diagnosed by the visual inspection or radiograph of a cavitated lesion. Dental professionals were not concerned about removal of the tooth structure at the time because most people had rampant caries and the teeth were extracted. The prevalence of caries has declined significantly in the past 30 years, and we now realize that early carious lesions can be treated nonoperatively. Caries is a reversible process. We need to detect dental caries at a much earlier stage so the tooth can remineralize. Radiographs and explorers do not detect lesions early enough to accomplish this. Other technologies have developed that allow caries detection while it is still in enamel. The DIFOTI™ uses fiber optic transillumination. Laser florescence is used by Diagnodent™. The QLF, which just received FDA approval, uses quantitative light-induced florescence. These devices provide a quantitative measurement that reveals whether an opportunity for remineralization exists or not. Determining if a carious lesion is active or inactive is possible with these new technologies.

When is the use of topical fluoride products indicated?

Each patient is an individual. A risk assessment should be performed on every patient in the practice. The need for topical fluoride applications and in-office topical fluorides is then based on the risk assessment. Fluoride is not age specific. Hygienists tend to give fluoride to children under the age of 16 whether they need it or not. On the other hand, many adults do not receive fluoride treatments even though they need it. If a patient is at high risk, provide an in-office fluoride treatment at least twice per year. Low risk individuals do not need fluoride treatments because they are therapeutic, not preventive. The goal of in-office fluoride treatment is to remineralize surfaces that are beginning to demineralize. Primary prevention is accomplished through frequent exposure to fluoridated water and fluoride toothpaste. In-office fluoride treatments are not frequent exposure so they are referred to as secondary prevention.

For primary prevention, patients must use a fluoride toothpaste at least twice per day. A child under the age of 6 should not use foams or gels because of possible ingestion. In-office fluoride varnish application is acceptable.

Should we be recommending antimicrobials and fluoride rinses?

Antimicrobials are appropriate for high risk patients if they are old enough to avoid ingestion. Fluoride rinses shouldn’t be used in children under 6 because they may swallow them. For high risk patients, fluoride rinse is great in addition to a fluoride toothpaste. The best results are gained from fluoride exposure about once every 4 hours. For high risk adults, a fluoride lozenge or fluoride tablet is also an option for topical fluoride exposure. However, brushing with a fluoride toothpaste should be the most highly encouraged strategy.

Should sealant usage be increased across the board?

Again, individual risk assessment is key. If a tooth surface of a young patient is sound and demineralization is not present, a sealant is not necessary. If an adult is starting to get demineralization, a sealant should be considered.

How can dental hygienists be more effective in the detection and treatment of caries?

I would like to see hygienists be more proactive in looking for early demineralization and in assessing caries risk. Often hygienists don’t think of caries as their own realm. If we can carefully document demineralization, then a more proactive approach can be implemented and patients can receive nonoperative treatment. Hygienists are in a very good position to detect carious lesions early.

Researchers are investigating replacing lactic acid-producing strains of S. mutans with nonacid-producing strains to eliminate caries. How close is such a breakthrough and is the manipulation of only one species of bacteria likely to solve the problem?

The breakthrough is not imminent and it is not knownwhether the manipulation of one species will solve the problem. Research is being conducted on a caries vaccine. A vaccine would actually increase the protein antigens that arederived from S.mutans, creating protective salivary IGA antibodies.The antibodies in the system prevent the S. mutans frombecoming cariogenic. While promising, this research is only inthe beginning phases.

REFERENCE

1. National Center for Health Statistics. Available at: www.cdc.gov/nchs/about/major/nhanes/survey_results_and_products.htm. Accessed August 16, 2004.

From Dimensions of Dental Hygiene. September 2004;2(9):28, 30.