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In a retrospective study in the fall 2007 Journal of Public Health Dentistry,1 researchers from Indiana University, Oregon Health and Science University, and Kaiser Permanente Northwest (KPNW) report that older adults may benefit more than children from community water fluoridation. The study received online news coverage from Medical News Today,2 Newswise,3 and Reuters Health.4

The authors reviewed administrative data from KPNW dental HMO members to evaluate the impact of community water fluoridation on dental treatment experiences and costs over a six-year period. They analyzed a 1990-1995 dataset of dental treatment costs and services provided to HMO participants, who resided in fluoridated and nonfluoridated regions in northwest Oregon (Portland and Salem areas) and southwest Washington (primarily Vancouver, WA). The study focused on dental services and procedures that community water fluoridation (CWF) could directly influence, including dental restorations and prescription fluorides.

After statistical analyses adjusting for impact of fluoridation, locale, and age on treatment costs and utilization, the authors determined that community water fluoridation was associated with reduced total and restorative costs among dental HMO members, but cautioned that the overall effects were “generally small.” The researchers attributed this to the study population of dental HMO subscribers, which was described as having relatively lower risk for dental disease, higher levels of dental utilization, and greater use of preventive procedures (e.g., sealants and fluoride supplements).

Importantly, in all study locations, the number of dental restorative procedures in the study population was higher among older HMO members living in areas with non-fluoridated water. As noted by the authors, the use of insurance data presented several limitations, since the study population was predominantly white (over 90%) and the data analysis did not address a range of unobserved variables (e.g., socioeconomic status and actual time spent living in specific water districts). Based on these and other methodological considerations, the authors indicated that their “findings may not be directly generalizable to the overall US population.” Still, the study sample offers useful population-based data for analyzing the impact of community water fluoridation on the use and costs of dental treatment for insured patients, particularly older individuals with access to care.

Funding support for the study was provided by a contract with the Centers for Disease Control and Prevention and the Alliance for Community Health Plans. For further study, the authors recommended more evaluation of differences in treatment costs (estimated savings) associated with community water fluoridation.

Along with other major health organizations, the ADA supports community water fluoridation as a safe and effective means of preventing tooth decay. The ADA also recommends fluoride supplementation for children who live in areas without optimal fluoride in their water. For more information, visit the ADA Statement on Water Fluoridation Efficacy and Safety and additional resources at  


1. Maupome G, Gullion CM, Peters D, Little SJ. A comparison of dental treatment utilization and costs by HMO members living in fluoridated and nonfluoridated areas. Journal of Public Health Dentistry 2007; 67(4): 224-233. Abstract available at: Accessed December 11, 2007.

2. It’s not just a kid thing: fluoridated tap water benefits older adults even more. Medical News Today, December 5, 2007. Available at: Accessed December 10, 2007.

3. Fluoridated water benefits older adults more than kids. Indiana University-Purdue University Indianapolis (press release), December 4, 2007. Available at: Accessed December 13, 2007.

4. Fluoride in tap water may help older teeth too. Reuters Health, December 14, 2007.

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Science in the News is a service by the American Dental Association (ADA) to present current information about science topics in the news. The ADA is a professional association of dentists committed to the public's oral health, ethics, science and professional advancement; leading a unified profession through initiatives in advocacy, education, research and the development of standards. As a science-based organization, the ADA's evaluation of the scientific evidence may change as more information becomes available. Your thoughts would be greatly appreciated.

Page Posted December 2007