Fluoridation: Part Two
By Mina Levi, DDS, 04/17/2014

In our last article, we talked about water fluoridation and answered questions like, “what is fluoride?” and “how does fluoride help with tooth decay?” In part two of our three part series, we will continue our discussion on fluoridation but will delve deeper into the topic and explore national levels of fluoridation and CDC recommendations.

Fluoridation San Francisco

National Levels

As of 2012, the total US population was about 313,914,040 people. About 232,534,910 people in the US are on community water systems (CWS), and 210,655,401 people in the US population are on fluoridated drinking water systems. This means that about 74% of people that are on community water systems are receiving fluoridated water. The District of Columbia region has the highest percentage of population receiving fluoridated water at 100% in comparison to all other states/regions. The next highest state percentage is Kentucky at 99.9%. The lowest state percentage is Hawaii; only 139,598 people out of 1,290,549 are receiving fluoridated water, about 10.8%. California is at about 63.7%.

CDC Recommendations and Comments

The CDC, the Centers for Disease Control and Prevention, has released findings and conclusions from studies on fluoridation.  The following are their official comments on the efficacy and risks of fluoride as well as their recommendations for fluoride use and water fluoridation:

Fluoride efficacy in preventing and controlling dental caries

· Fluoride effects enamel and inhibits dental caries only when incorporated into developing dental enamel
· Topical fluoride on the enamel surface remineralizes the enamel when the pH drops in the mouth in response to acid production
· As fluoride concentrates in the dental plaque that accumulates in the mouth, it inhibits the process by which cariogenic (caries-causing) bacteria metabolize and produce acid.
· Fluoride works primarily after teeth have erupted, especially when small amounts are maintained constantly in the mouth.
· Both adults and children benefit from fluoride

Risk for enamel fluorosis

· Concerns regarding the risk for enamel fluorosis are limited to children less than eight years of age
· Most fluorosis today is of the mildest form, which effects neither cosmetic appearance nor dental function
· A low prevalence of the milder forms of fluorosis has been accepted as a reasonable consequence balanced against substantial protection from dental caries
· In the severe form, enamel might break away which results in excessive wearing of the teeth
· Even in the severe form, fluorosis is considered a cosmetic effect and not a functional effect
· Cases of moderate to severe forms occur even among children living in areas with low fluoride concentrations

Guidelines for fluoride use

· It is recommended for fluoride use to include an optimally adjusted concentration of fluoride in community drinking water to maximize caries prevention and limit enamel fluorosis
· The approved concentration ranges from 0.7 ppm to 1.2 ppm depending on the average daily air temperature of the area
· The EPA, which is responsible for the safety and quality of drinking water in the United States, sets a maximum allowable limit for fluoride in drinking water at 4 ppm and a secondary limit at 2 ppm

Fluoridated drinking water and its effects

· Initial studies of community drinking water fluoridation demonstrated that reductions in childhood dental caries attributed to fluoridation were 50-60%
· More recent estimates are lower (18-40%) which is likely caused by the increasing use of fluoride from other sources like fluoridated toothpaste
· Studies of benefits of fluoridation for adults is more complicated because their fluoride histories are potentially more varied and their tooth loss or restorations might be caused by problems other than caries
· Nevertheless, adults are reported to receive caries-preventive benefits from community drinking water fluoridation, particularly advantageous for those above fifty years of age
· Prevalence of root caries among adults is inversely related to fluoride concentration in community drinking water (lower fluoride levels correspond with higher root caries levels)
· Caries reduction is considerably higher among persons in low socioeconomic status (SES) than among those in high SES.
· Enamel fluorosis occurs among some people in all communities, even those with a low natural concentration of fluoride
· In the most recent study, in communities with water containing 0.7-1.2ppm fluoride had a prevalence of 1.3% for the moderate form of fluorosis and 0% for the severe form

Conclusions

· When used appropriately, fluoride is a safe and effective agent that can be used to prevent and control dental caries
· Fluoride has contributed profoundly to the improved dental health of persons in the US
· To ensure additional gains in oral health, water fluoridation should be extended to additional communities, and fluoridated toothpaste should be used widely
· Adoption of these recommendations could lead to considerable savings in public and private resources without compromising the benefit of fluoride

For more information about the reported comments and recommendations of the CDC, you can visit the CDC website at www.cdc.gov. Next week in the last article of the three-part series, we will take a look at water fluoridation from a local standpoint, visiting the bay area’s levels of fluoridation and community responses. If you have any specific questions or would like us to discuss another water fluoridation issue, please give us a call at (415) 513-5066 or visit us on the web at www.minalevidds.com.

Topics: CDC, national levels, national levels of water fluoridation, water fluoridation, fluoride, fluoridation, tooth enamel, dental cavities, dental decay, tooth decay, public water fluoridation, cavities, dental caries,oral bacteria, fluoridated toothpaste, fluoride toothpaste, controversy, dentist San Francisco