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Study: More decay in town with discontinued fluoridation

February 19, 2016

By Michelle Manchir

Calgary, Alberta — Children who lived in a Canadian city that discontinued water fluoridation experienced more tooth decay than children who lived in a continuously fluoridated community, according to a study published in February in Community Dentistry and Oral Epidemiology.
Researchers examined the short-term impact of fluoridation cessation on 2nd grade children's caries experiences in both Calgary, where fluoridation was discontinued in 2011, and in another Canadian city, Edmonton, where water has been fluoridated since 1967. The number of primary tooth surfaces with decay per child increased by 3.8 surfaces in Calgary during the time frame of the study, as compared to 2.1 in Edmonton.
"This study points to the conclusion that tooth decay has worsened following removal of fluoride from drinking water, especially in primary teeth, and it will be important to continue monitoring these trends," said Lindsay McLaren, Ph.D., from the University of Calgary's Cumming School of Medicine and O'Brien Institute for Public Health, the study's lead author, in a press release from the university.
For the study, researchers examined data from population-based samples of more than 5,000 school children in the two cities and analyzed change over time (2004-05 to 2013-14.) Calgary and Edmonton were the cities used because Calgary began the practice in 1991 but ended it in 2011, while Edmonton has not stopped fluoridating since fluoridation began there in 1967, according to the study.
Many communities across the U.S. and North America are debating and doubting the proven benefits of community water fluoridation. According to a press release about the study from the University of Calgary, "there are currently few published studies that look at the effects of fluoridation cessation. Researchers from the paper hope their study can be explored by decision makers who are involved in these discussion."
Said Dr. Steven Patterson, a professor at the school of dentistry at the University of Alberta, "The early effects of fluoridation cessation found in this study support the role of water fluoridation in contributing to improved oral health of children and that it is a public health measure worth maintaining."
The ADA endorses the fluoridation of community water supplies as safe and effective for preventing tooth decay. The Association, along with state and local dental societies, continues to work with federal, state, local agencies and community coalitions to increase the number of communities benefiting from water fluoridation.
For more information from the ADA about water fluoridation, or contact Jane McGinley, ADA manager of fluoridation and preventive health activities, at