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Two water fluoridation reports released in June

July 13, 2015

By Michelle Manchir

Two significant reports about water fluoridation were published in June.

The Health Research Board of Ireland published "Health Effects of Water Fluoridation," an in-depth review of existing research, finding no definitive evidence that community water fluoridation has negative health effects.

In 2014, the Ireland Department of Health asked the Health Research Board to determine the positive or negative impact on the systemic health, including oral health but excluding dental health, of the population for those exposed to artificially fluoridated water between 0.4 and 1.5 parts per million.  

Using a systematic review process, the HRB's report contains a detailed analysis of the evidence available in the peer-reviewed literature. The topics addressed were musculoskeletal effects, IQ and neurological manifestations, cancer, cardiovascular disease and other potential health effects.

According to a press release, Dr. Marie Sutton, lead author of the report at the HRB stated, "Having examined the evidence, and given the lack of studies of appropriate design, further research would be required to establish any link between fluoride and negative health effects."

The second review, "Water Fluoridation for the Prevention of Dental Caries," was designed to study the effects of water fluoridation on the prevention of tooth decay and dental fluorosis. Published by the Cochrane Collaboration, the following were among the key findings:

  • There is insufficient information to determine whether water fluoridation results in a change in tooth decay across socioeconomic status levels.
  • There is insufficient information to determine the effect of stopping water fluoridation on tooth decay levels.
  • No studies that aimed to determine the effectiveness of water fluoridation for preventing caries in adults met the review's inclusion criteria.
  • The authors noted that there is much debate around the approach used to assess the quality of evidence within this review when applied to public health interventions.

The Cochrane approach favors the use of randomized controlled trials which is the preferred study design for studies comparing different clinical treatments among individual patients, said Jane McGinley, manager for fluoridation and preventive health activities for the ADA Council on Access, Prevention and Interprofessional Relations.

Randomized controlled trials typically are not feasible for public health measures that occur at the community level such as community water fluoridation.  As a result, a number of more recent research papers published in the peer-reviewed literature were not considered in the Cochrane review, Ms. McGinley said.

The U.S. Community Services Task Force conducts systematic reviews of interventions in many public health topics to find which program and policy interventions have proven to be effective, have additional benefits, potential harms, cost savings, implementation issues and other factors.  In April 2013, the Task Force recommended community water fluoridation based on evidence of effectiveness in reducing dental caries across populations. The review was conducted on behalf of the Task Force by an independent team of specialists with expertise in a broad range of research, practice and policy expertise in community preventive services, public health, health promotion and disease prevention.

The ADA strongly endorses the U.S. Community Preventive Services Task Force recommendation that found fluoridation to be effective.

As a science-based organization, the ADA supports ongoing research on the safety and effectiveness of community water fluoridation.

For more information about fluoride and water fluoridation, visit ADA.org/fluoride or contact Ms. McGinley,