By Maria Cohut
Fact checked by Isabel Godfrey
If you live in the United States, it is highly likely that the tap water you use is enriched with fluoride, a substance that helps prevent tooth decay. However, due to concerns that fluoridated water may increase the risk of other diseases, the capital city of Alaska stopped this practice. What happened?
Most regions of the U.S. and some other countries across the world add specific quantities of fluoride to their community water supplies.
They do this because fluoride can effectively prevent or, in some cases, reverse the formation of tooth cavities. Fluoride promotes the remineralization of teeth, strengthening their enamel and thus helping them fight off the bacteria that cause decay.
For this same reason, most types of toothpaste and many mouthwash products contain some fluoride. However, ingested fluoride tends to accumulate in our bones, which has led some people to worry that drinking fluoridated water might increase the risk of various health problems. These include cancer, particularly osteosarcoma, which is a type of cancer that starts in the bones.
Such concerns led the City Assembly of Juneau to direct the cessation of fluoridation of community water in their area, with effect from 2007.
In a new study that the journal BMC Oral Health recently published, a research team from the College of Health Sciences at Walden University in Minneapolis, MN, and the College of Health at the University of Alaska Anchorage has investigated the effects of this decision on the oral health of the young inhabitants of Juneau.
Increase in requests for dental care
The research team, which Jennifer Meyer from the University of Alaska Anchorage led, looked at the dental records of all the children and adolescents in Juneau who accessed dental health services through Medicaid during 2003 and 2012.
Meyer and colleagues deemed 2003 an “optimal community water fluoridation year,” and they analyzed the dental claims of 853 children and teenagers aged up to 18 years who received dental care that year.
The researchers compared this data with that of 1,052 children and adolescents who received dental care in 2012, 5 years after the City Assembly of Juneau had voted for the cessation of community water fluoridation.
Data analysis revealed that, as the study authors write, “the mean number of caries-related procedures for the 0- to 18-year-old age groups was significantly higher” in the 2012 treatment group, when community water no longer contained fluoride, than in the 2003 group, before the decision to end water fluoridation.
More specifically, “the odds of a child or adolescent undergoing a dental caries procedure in 2003 was 25.2 [percent] less than that of a child or adolescent in ,” the study authors explain.
This suggests that the added fluoride did have a protective effect on oral health, which is missing now that community water supplies no longer go through the fluoridation process.
Natural water fluoride under optimal levels
Meyer and team also found that, as a consequence, the costs of providing dental care to Juneau inhabitants aged 0–18 years had significantly increased in 2012 compared with 2003, even after adjusting to accommodate the effects of inflation.
However, a more intriguing finding of the study was that children younger than 7 years received more numerous interventions for the treatment of cavities in 2012 than children who were in the same age group in 2003.
Once more, the researchers found a corresponding increase in costs for dental care in young children in 2012.
“After adjusting for inflation, we observed a caries treatment cost increase of 73 [percent] attributable to [community water fluoridation] cessation and estimated at approximately $255.60,” the authors write, concluding:
“The results of this study confirm the benefits of optimal [community water fluoridation] supported by previous research and can contribute additional research-based evidence regarding the oral health consequences and costs that can arise when [community water fluoridation] is discontinued.”
Since fluoride occurs naturally in water, community water sources for Juneau still contain some of this mineral even after the cessation of artificial fluoridation.
However, Meyer and team note that fluoride naturally occurs in much smaller quantities than those that experts consider “optimal for caries prevention.” In fact, fluoride levels in Juneau’s water sources are more than 10 times lower than the optimal levels for oral health.
“Previous research indicates that without the presence of optimal levels of fluoride in drinking water, and thus in the mouth and saliva, teeth may form with weaker enamel and lack the ability to remineralize early signs of decay,” the study researchers warn.