The American Dental Association (ADA) announced on Saturday that it will continue endorsing the “optimal levels” for community water fluoridation alongside other major health organizations such as the American Academy of Pediatrics and the U.S. Centers for Disease Control and Prevention.
ADA’s statement comes a day after the Cochrane Library published a review of 157 studies, which concluded that the “benefits of fluoride in water supplies may be smaller than they were before the widespread addition of fluoride to toothpaste.” The review also indicated that adding fluoride to water supplies may lead to slightly less tooth decay in children’s baby teeth and that it may also result in a higher number of children being free of tooth decay.
However, Linda J. Edgar, D.D.S., ADA’s president, emphasized that fluoridation prevents at least a quarter of tooth decay in both children and adults throughout their lifespans. “Optimally fluoridated water is accessible to communities regardless of socioeconomic status, education, or other social variables,” she added. “Even in an era with widespread availability of fluoride from various sources, other studies show that community water fluoridation prevents at least 25% of tooth decay. The scientific weight of sound evidence around the benefit of community water fluoridation is clear and compelling.”
According to the U.S. Centers for Disease Control and Prevention, water fluoridation and fluoride toothpaste work together to help prevent tooth decay and provide more protection against decay than using either one alone. Fluoridated water maintains a low level of fluoride in the mouth throughout the day, while fluoride toothpaste delivers higher concentrations at crucial times, such as bedtime.
NFAC: Recent studies excluded from review
While the ADA is aware of many recent studies that were excluded from the Cochrane review, which indicate negative impacts on public health when fluoride is removed from the water supply, the National Fluoridation Advisory Committee (NFAC) also weighed in on the review’s limitations.
“The study’s exclusion criteria meant that highly relevant research from over the past decade showing significant increases in tooth decay in communities like Juneau, Alaska, Calgary, Canada, and other areas after their decision to remove fluoride from water supplies were not included,” said NFAC member Catherine Hayes, D.M.D., SM, DMSc.
The NFAC also noted that the review did not rely on enough high-quality studies, suggesting that authors should exercise caution in interpreting results based on the very small number of recent studies. “Normally, meta-analyses and systematic reviews are only conducted with substantial numbers of relevant high-quality studies,” Dr. Hayes stated. “However, there were only a small number of recent studies on which the conclusions are based—only two for primary caries (cavities in baby teeth) outcomes and maybe a few more for permanent caries (cavities in adult teeth).”
Dr. Hayes also pointed out that the analysts at Cochrane excluded reliable studies based on the year of data collection rather than the quality and reliability of the data. “This is an important oversight that cannot be ignored. Additionally, Cochrane researchers noted significant cost savings due to fluoridation, which was also not included in the summary.”
