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 

"CDA supports fluoridation of municipal drinking water (at minimum levels required for efficacy as recommended by the Federal-Provincial-Territorial Committee on Drinking Water) as a safe, effective and economical means of preventing dental caries in all age groups. Fluoride levels in the water supplies should be monitored and adjusted to ensure consistency in concentrations and avoid fluctuations." More…  

Health Canada

"Many studies have shown that fluoridated drinking water is a safe, effective and cost effective public health measure which significantly reduces the number of cavities in children's teeth." 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...

The Chief Medical Officer of Health for Ontario (2012)

“All Ontarians should have access to optimally flurodiated drinking water. Fluoridation is highly effective and can reach large populations who benefit from it. Other preventive services may be less accessible to people without private dental insurance or those living on low incomes, which further reinforces the importance of “population-based” prevention such as community water fluoridation.” 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

"Because of its contribution to the dramatic decline in tooth decay in the United States since the 1960s, the Centers for Disease Control and Prevention (CDC) named community water fluoridation one of 10 great public health achievements of the 20th century." More… 

U.S. Surgeon General

"Community water fluoridation is one of the most practical, cost-effective, equitable, and safe measures communities can take to prevent tooth decay and improve oral health." More…

World Health Organization

“Dental cavities can be prevented by maintaining a constant low level of fluoride in the oral cavity. Fluoride can be obtained from fluoridated drinking water, salt, milk and toothpaste, as well as from professionallyapplied fluoride or mouth rinse. Long-term exposure to an optimal level of fluoride results in fewer dental cavities in both children and adults.” 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. Oral Health – More Than Just Cavities: A Report by Ontario’s Chief Medical Officer of Health (April 2012)

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. Risk to Oral Health and Intervention: Fluorides
  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 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.

Top of this page