Community Water Fluoridation


Why the Ontario Dental Association Supports Community Water Fluoridation

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

CWF has had a great effect in cavity 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.

The History of Water Fluoridation in Canada

The connection between fluoride and dental health began to be seriously explored in the early twentieth century. 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. At last count, 9,229,015 people in Ontario, or 75.9 percent of the provincial population, have access to fluoridated water.i Currently, CWF is practised in more than 30 countries around the world, providing more than 370 million people with optimally fluoridated water.ii

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The Benefits

After the common cold, tooth decay is the second most common disease in the world, and it is also something that is preventable.iii Tooth decay is also one of the leading causes of absences from school. CWF can reduce tooth decay in children’s primary teeth by up to 60 percent, and in their permanent teeth by up to 35 percent. Adults experience a 20 to 40 percent reduction in tooth decay from lifelong exposure to water fluoridation.iv

Limited access to dental care and poor oral hygiene can lead to severe health complications as well as negative social consequences. Fluoridating community water benefits everyone living in that community, regardless of age or socio-economic status.v vi vii

As dentists, we want what is best for our patients. CWF is the single most effective public health measure for preventing tooth decay — it’s just that simple.viii

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The Science

Reputable scientific studies conducted throughout the past 70 years have consistently shown that fluoridation of community water supplies is a safe and effective way to prevent dental decay in both children and adults.ix x

Fluoride works by making the outer layer of teeth stronger and less likely to get cavities. It can also prevent or even reverse the decay process.xi When ingested, fluoride not only becomes part of the tooth structures during tooth formation, but it also provides topical protection. Ingested fluoride is retained in saliva and is continually surrounding the tooth.xii This preventive measure is especially important for our aging baby-boomer population, which will be vulnerable to dental diseases of aging such as root decay.

In Ontario, fluoride additives must meet rigorous standards of quality and purity before they can be used. Studies show that when fluoride is added to water at recommended levels in Ontario and across the country, it is not linked to any adverse health effects.xiii Health Canada has determined that the optimal concentration of fluoride in drinking water for dental health is 0.7 mg/L.xiv Acute fluoride toxicity occurring from the ingestion of optimally fluoridated water is impossible.xv

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The Economics

CWF saves money, in addition to teeth. According to the Centers for Disease Control and Prevention, for every dollar you spend fluoridating the community water supply, $38 is saved in oral health care.xvi The average lifetime cost per person to fluoridate a community can be less than the cost of one dental filling.xvii

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What the Experts Say About CWF

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...

Canadian Association of Public Health Dentistry 

"The Canadian Association of Public Health Dentistry endorses community water fluoridation as an important public health measure to prevent dental caries (tooth decay) in a population. It is safe, effective, ethical, legal, reduces oral health disparities and is cost-effective." More...

The Chief Medical Officer of Health for Ontario (April 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 Dr. Vivek H. Murthy (2014 - Present)

"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. Water fluoridation’s biggest advantage is that it is the best method for delivering fluoride to all members of the community regardless of age, education, income level, or access to routine dental care. Fluoride’s effectiveness in preventing tooth decay extends throughout life, resulting in fewer and less severe cavities. In fact, each generation born since the implementation of water fluoridation has enjoyed better dental health than the preceding generation." More…

World Health Organization, Oral Health (2012)

“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…

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Frequently Asked Questions

Listed below are answers to commonly asked questions about fluoride. 

What is fluoride?

Fluoride is a mineral found in soil, water (both fresh and salt) and various foods.

How does fluoride prevent tooth decay?

Fluoride has a positive effect on oral health by making teeth more resistant to decay. Fluoride can also prevent or even reverse tooth decay that has started.

Where do I get the fluoride that prevents tooth decay?

For many Canadians, fluoride is in public drinking water, which provides protection to the entire community. Fluoride toothpastes and rinses are available for purchase, and your dentist can provide professional fluoride products such as gels and varnish.

What is dental fluorosis?

Dental fluorosis is a change in the appearance of teeth. It is caused when higher than optimal amounts of fluoride are ingested in early childhood. In its mildest and most common form, it affects the look of the tooth with small white specks appearing on a child’s teeth.

Is dental fluorosis a concern in Canada?

The Canadian Health Measures Survey 2007-2009 found that dental fluorosis is not an issue of concern for the vast majority of children (84%). Some children (16%) have mild forms of fluorosis that often go unnoticed by both the children and their parents.

What is water fluoridation?

Water fluoridation is the process of adjusting the level of fluoride in a public drinking water supply to optimize the dental benefits of preventing tooth decay.

Why is fluoride added to the public drinking water if it is available in other ways?

Fluoride is added to public drinking water to protect all members of the community from tooth decay. Community water fluoridation is a safe and effective way of preventing tooth decay at a low cost.

Who watches the fluoride levels in the drinking water?

The Federal-Provincial-Territorial Committee on Drinking Water makes recommendations about the optimal level of fluoride in public drinking water to prevent tooth decay. The recommended level takes into account that Canadians receive fluoride from other sources such as food and beverages.

What does an “optimal” level of water fluoridation mean?

An optimal level of water fluoridation is achieved by adjusting the level of fluoride in the water to achieve the right balance between the benefit of preventing tooth decay and the risk of developing dental fluorosis.

 Are there any health risks associated with water fluoridation?

With the exception of dental fluorosis, scientific studies have not found any credible link between water fluoridation and adverse health effects.

Should I be using fluoridated toothpaste with my child?

For children from birth to 3 years of age, the use of fluoridated toothpaste is determined by the level of risk of tooth decay. Parents should consult a health professional to determine whether their child up to 3 years of age is at risk of developing tooth decay. If such a risk exists, the child’s teeth should be brushed by an adult using a minimal amount (a portion the size of a grain of rice) of fluoridated toothpaste. Use of fluoridated toothpaste in a small amount has been determined to achieve a balance between the benefits of fluoride and the risk of developing fluorosis. If the child is not considered to be at risk, the teeth should be brushed by an adult using a toothbrush moistened only with water.

For children from 3 to 6 years of age, only a small amount (a portion the size of a green pea) of fluoridated toothpaste should be used. Children in this age group should be assisted by an adult in brushing their teeth.

Why do young children need to be assisted or supervised with tooth brushing?

Young children tend to swallow toothpaste when they are brushing, which may increase their exposure to fluoride and contribute to dental fluorosis. For this reason, children need to be assisted or supervised with tooth brushing. An adult needs to ensure that an appropriate amount of toothpaste is used, that the child spits out the toothpaste rather than swallows it, and that the teeth are cleaned effectively.

How do I know if my child is getting enough fluoride protection?

Your dentist is able to assess your child’s risk of developing tooth decay and advise you of an appropriate level of fluoride protection.

(Source: Canadian Dental Association)

The ODA understands you may have more questions about fluoride. Visit the American Academy of Pediatrics’ Campaign for Dental Health website to find out about the history of fluoride, how it is used, how it works and what the experts say: 

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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.
ii Office of the Prime Minister’s Chief Science Advisor and the Royal Society of New Zealand. Health effects of water fluoridation: A review of the scientific evidence. August 2014. Available at:
iii U.S. National Library of Medicine. Dental Cavities. 2014. Available at: 
iv American Dental Association. Fluoridation facts. 2005. As quoted in King, A., Chief Medical Officer of Health. Oral Health – More Than Just Cavities. April 2012. Available at:  
Parnell, C., Whelton, H., O’Mullane D. “Water Fluoridation.” European Archives of Paediatric Dentistry. 2009; 10 (3):141-148.
vi Wong, E. The Real Cost of Removing Water Fluoridation: A Health Equity Impact Assessment. 2013. Wellesley Institute. Available at:  
vii McLaren, L., Emery Herbert, J.C. “Drinking Water Fluoridation and Oral Health Inequities in Canadian Children.” Canadian Journal of Public Health. 2012. Available at:  
viii American Dental Association. 10 Reasons to Fluoridate Public Water. 2012. Available at:  
ix American Dental Association. Fluoride in Water. Available at:  
The U.S. Community Services Task Force. Preventing Dental Caries: Community Water Fluoridation. 2013. Available at:  
xi Canadian Dental Association. Fluoride FAQs. Available at:
xii American Dental Association. Fluoridation Facts. 2005. Available at:
xiii Rabb-Waytowich, D. "Water Fluoridation in Canada: Past and Present." J Can Dent Assoc. 2009 July;75(6):451-4 and McDonagh, M.S, et al. “Systematic Review of Water Fluoridation.” BMJ. 2000 Oct 7;321(7265):855-9. As quoted in King, A. Chief Medical Officer of Health. Letter to City of Windsor. 2013. Available at:
xiv Health Canada. Guidelines for Canadian Drinking Water Quality. Guideline Technical Document. Fluoride. Ottawa, Ontario 2010. Available at:
xv Whitford, G.M. “The Metabolism and Toxicity of Fluoride” 2d rev. ed. Monographs in Oral Science, Vol. 16. Basel, Switzerland: Karger, 1996. As quoted in American Dental Association. Fluoridation Facts. 2005. Available at:
xvi Centers for Disease Control. Community Water Fluoridation. Available at:
xvii 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

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