Community Water Fluoridation


Why the Ontario Dental Association Supports Community Water Fluoridation

Community water fluoridation is a safe and effective means of preventing dental decay. Our position is based on the overwhelming scientific evidence available, and is driven by our dedication to the provision of exemplary oral health care to our patients and communities.

In our Special Report, Tooth Decay in Ontario's Children: An Ounce of Prevention – A Pound of Cure, the Ontario Dental Association (ODA) recognized that dental decay is the most frequent condition suffered by children other than the common cold, and is one of the leading absences from school. Children at high risk for dental carries need access to a number of different protective and preventative therapies to reduce tooth decay. The cost of adding fluoride to regional drinking water is minimal when compared to the large costs of restorative dental surgery for children living in regions without fluoridation.1

Community water fluoridation has had a great effect in caries prevention and there are additional effective approaches that should also be considered. Experts agree there is a need to strongly support the use of fluorides, particularly fluoridation of community water supplies. As this measure alone is insufficient for high risk groups, governments should also incorporate fluoride varnishes and remineralization agents into dental programs. There is a crisis in dental caries in some populations and we need to target these groups with the most appropriate interventions.

The ODA is saying to the public and the government of Ontario that it's time to stand up for community water fluoridation. It is important to your family and your community.

The History of Water Fluoridation in Canada

The connection between fluoride and dental health began to be seriously explored in the early twentieth century. In the 1930s, dental scientists documented that the occurrence and severity of tooth decay was lower among people whose water supplies contained higher levels of natural fluoride.2

By the 1950, communities across North America had begun fluoridating their water supplies. Ontario was one of the first places in the world to introduce community water fluoridation as a public health initiative to reduce tooth decay.

The first Canadian community water fluoridation trials began in Brantford, Ontario in 1945. Today, 9,229,015 people in Ontario, or 75.9 percent of the provincial population, have access to fluoridated water.3

Frequently Asked Questions

Adding fluoride to public drinking water is still the most economical means of giving the benefits of fluoride to all members of the community. Not only do children need fluoride protection while their teeth are developing, adults need it to prevent cavities as well.  

What exactly is fluoride?
Fluoride is a mineral found in rocks and soil. When water passes over rock formations, it dissolves fluoride compounds that are present, releasing fluoride ions. Therefore, amounts of fluoride are naturally present in all water sources.

How does fluoride prevent tooth decay?
Fluoride works by stopping or even reversing the tooth decay process. It keeps the enamel of the tooth strong and solid by preventing the loss of important minerals. Fluoride's main effect occurs after the tooth has erupted above the gum, when small amounts of fluoride are maintained in the mouth in saliva.

Where do I get fluoride from?
Fluoride is provided through drinking water, toothpaste, mouthwash and supplements (tablets or drops). Gels and rinses applied by your dentist may also contain fluoride.

If fluoride is available in other ways, why is it added to our drinking water?
Fluoridation of community water supplies is the best way to provide oral health protection to a large number of people at a low cost. All members of a community can have the same benefits of fluoride in their water, regardless of their ages and socioeconomic status.

Who is responsible for the fluoride levels in our drinking water?
The responsibility of fluoridation of drinking water supplies is a decision that is made by each municipality, in collaboration with the provincial/territorial government and Health Canada. Together, through the Federal-Provincial-Territorial Committee on Drinking Water, both levels of government develop the Guidelines for Canadian Drinking Water Quality. These guidelines are reviewed and revised periodically to take into account new evidence-based scientific knowledge. 

According to Health Canada, “Health Canada’s Chief Dental Officer has reviewed the available science on dental effects of fluoride, and sought external expert advice from the scientific dental community. Experts provided a recommendation on the optimal level, which was accepted by Health Canada’s Chief Dental Officer. As a result, the optimal concentration of fluoride in drinking water for dental health has been determined to be 0.7 mg/L for communities who wish to fluoridate. This concentration provides optimal dental health benefits and is well below the maximum acceptable concentration to protect against adverse effects [emphasis added].”

Should we stop drinking fluoridated water if we are getting it from other sources?  
For most individuals, only using fluoridated toothpaste is not enough; the oral health benefits from CWF build on those from fluoride toothpaste. The fact that individuals receive fluoride from multiple sources is taken into account when recommended water fluoridation levels are determined. In 2008, a Fluoride Expert Panel recommended Health Canada “adopt a level of 0.7 mg/L as the optimal target concentration for fluoride in drinking water, which would prevent excessive intake of fluoride through multiple sources of exposure.” Greater lifetime exposure to CWF has also been found to be connected to lower decay rates.

I've been hearing about health risks associated with water fluoridation. Is this true?  

In 2010, after referring to over 400 published scientific studies, Health Canada released a 104 page document on “Guidelines for Canadian Drinking Water Quality- Guideline Document-Fluoride”. In this report, Health Canada explains that: “The weight of evidence from all currently available studies does not support a link between exposure to fluoride in drinking water at 1.5 mg/L and any adverse health effects, including those related to cancer, immunotoxicity, reproductive/developmental toxicity, genotoxicity and/or neurotoxicity. It also does not support a link between fluoride exposure and intelligence quotient deficit, as there are significant concerns regarding the relevant studies, including quality, credibility, and methodological weaknesses.”

It should be noted that Health Canada has determined that the optimal concentration of fluoride in drinking water for dental health be 0.7mg/L for communities that wish to fluoridate. Therefore, even when double this amount is used it is not linked to any adverse health effects.

What the National and International Experts Say About Water Fluoridation

Canadian Dental Association 

The Canadian Dental Association supports the appropriate use of fluorides in dentistry as one of the most successful preventive health measures in the history of health care. Over 50 years of extensive research throughout the world has consistently demonstrated the safety and effectiveness of fluorides in the prevention of dental caries. More…  

Ontario Association of Public Health Dentistry 

The Ontario Association of Public Health Dentistry (OAPHD) supports the fluoridation of municipal drinking water. It recommends water fluoridation as a safe, effective and economical public health measure to prevent dental caries in all age groups. More...

American Dental Association 

The American Dental Association unreservedly endorses the fluoridation of community water supplies as safe, effective and necessary in preventing tooth decay. This support has been the Association's position since policy was first adopted in 1950. More…

U.S. Centers for Disease Control and Prevention

Community water fluoridation prevents tooth decay safely and effectively. The Center for Disease Control identifies it as one of 10 great public health achievements of the 20th century. More… 

U.S. Surgeon General

…[C]ommunity water fluoridation continues to be the most cost-effective, equitable and safe means to provide protection from tooth decay in a community. Scientific studies have found that people living in communities with fluoridated water have fewer cavities than those living where the water is not fluoridated. For more than 50 years, small amounts of fluoride have been added to drinking water supplies in the United States where naturally-occurring fluoride levels are too low to protect teeth from decay. Over 8,000 communities are currently adjusting the fluoride in their community’s water to a level that can protect the oral health of their citizens. More…

World Health Organization

…[T]he experts reaffirmed the efficiency, cost-effectiveness, and safety of the daily use of optimal fluoride. They confirmed that universal access to fluoride for dental health is a part of the basic human right to health. More…

What You Can Do to Support Water Fluoridation in Your Community

The first thing you should do is get to know the facts.

Read what respected national and international health bodies are saying about the use of fluoridated water and the underlying benefits to communities around the world.

If your community is one of the few in Ontario without water fluoridation, contact your local councilor and mayor and ask them why they haven’t implemented water fluoridation in your community. In the past year, some councils in municipalities across Ontario revisited the issue of water fluoridation in their community. The ODA actively participated in these local debates, providing advice and scientific evidence on the beneficial use of fluoride.


Ontario Dental Association:

  1. News Release: The ODA Applauds Decision To Keep Fluoride in Toronto's Drinking Water
  2. Fact Sheet - Fluoridation: Myths and Facts
  3. Fluoridation articles from Ontario Dentist - October 2005

Canadian Dental Association:

  1. CDA Position on Use of Fluorides in Caries Prevention

Ontario Chief Medical Officer of Health:

  1. Drinking Water Fluoridation: Statement from Dr. Arlene King, Chief Medical Officer of Health 
  2. Value of Water Fluoridation - May 31, 2010

Health Canada:

  1. Fluoride and Human Health 
  2. Summary Report on the Findings of the Oral Health Component of the Canadian Health Measures Survey 2007-2009
  3. Canadian Health Measures Survey Oral Health Statistics 2007-2009

American Dental Association

  1. Fluoride & Fluoridation Home Page 
  2. American Dental Association and CDC Celebrate 60th Anniversary of Community Water Fluoridation
  3. Fluoridation Facts

US Centers for Disease Control and Prevention

  1. Community Water Fluoridation Home Page
  2. Fluoride Legislative User Information Database (FLUID)

World Health Organization

  1. Water fluoridation website page
  2. Call to Action to Promote Dental Health by Using Fluoride (Joint release with the FDI World Dental Federation and the International Association for Dental Research)
  3. Briefing on Fluoride in Drinking Water


  1. Globe & Mail editorial: "Calgary's Council Votes Against Teeth" (February 24, 2011)


1 Griffin, S.O., Jones, K. & Tomar, S.L. (2001) An Economic Evaluation of Community Water Fluoridation. Journal of Public Health Dentistry, 61(2): 78-86

2 U.S. Centers for Disease Control and Prevention website, Fluoridation Basics.

3 Community Dental Health Services Research Unit (2007) Provincial and territorial estimates for community water fluoridation coverage in 2007. Toronto: Faculty of Dentistry, University of Toronto.

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