Epidemiology of Caries and the Role of Fluoride

The message we have been taught is caries is a disease of the past, and although the common perception is that kids no longer get much tooth decay, the most recent large-scale data continues to suggest that we have not eradicated the problem just yet. These data, from the 1999-2004 National Health and Nutrition Examination (NHANES) Survey, show that overall, dental caries in deciduous (baby) teeth of children ages 2 to 11 declined from the early 1970s until the mid-1990s. From the mid-1990s until the most recent survey, the trend has actually reversed: a small but significant increase in primary decay was found, with the trend being more severe in younger children.1 Separate from the NIDR Survey, the US Surgeon General's report in 2000 confirmed caries remains the number one childhood disease among 5-17 year-olds.2 Among this group, caries is 5X as prevalent as asthma and 7X as common as hay fever. These data highlight the ongoing need for fluoride therapy.

Image showing untreated dental caries in children ages 2–19 in the United States.
US Surgeon General's report in 2000

In addition to the levels of disease that we do see and treat, there is also a concern about the amount of caries that go untreated. National surveys in the United States have reported the levels of untreated dental caries, in children ages 2-19 in the United States, during three time periods: 1971-1974; 1988-1994; and 2001-2004. Although the percentage of untreated cavities declined from 1971-1974 (25.0% in children ages 2-5 and 54.7% in children ages 6-19), data for the most recent time period measured still show high levels of untreated cavities: 19.5% in children ages 2-5 and 22.9% in children ages 6-19.3 Over the same time frame, 26% of adults 20 to 64 were reported to have untreated decay.4

A broad review of the epidemiology has been published,5 which concludes "Caries is a worldwide problem associated with plaque, microorganisms, and the intake of carbohydrates. The presence of fluoride in the oral environment attenuates the process." While we have made a lot of progress with the use of fluoride, there is still more work to do.

Image showing incipient lesions.

Examining secondary caries...it has been estimated approximately 50% of the amalgam restorations that need replacing are due to recurrent caries. You have heard it a thousand times... "My teeth are all filled; there is no room for more decay!" A filling, as we know, can be successfully replaced twice before a more permanent restoration is indicated. Again, the role of fluoride therapy here is clear.

And what about root surfaces? Kids are all grown up and out of the house; are Mom and Dad justified in using a non fluoridated toothpaste? It has been estimated that by the age of 50 at least one-half of the population will have at least 1 root surface caries lesion. The ongoing need for fluoride treatment is not limited to specific age groups. All patients can benefit from appropriate fluoride therapy.

Image showing dental caries risks.
Image showing dental caries risks.
Dental Caries Risks

The changes in caries distribution are important in understanding and planning for preventive approaches for all age groups throughout the world. Changes in the clinical management of the caries process and an emphasis on early treatment mean we now lack estimations for both non-operative and operative treatments. The understanding of the caries process, in terms of a dynamic continuum of demineralization and remineralization, means epidemiological studies will soon change in the level of caries information and detection. The visual-tactile examination using diagnostic criteria such as established by Radike6 may no longer be sufficient to collect caries data in light of changing technologies for early detection and the need to measure non-cavitated carious lesions. Pitts et al.7 discuss the current caries epidemiology with respect to an emphasis on diagnostic standards.