Key Takeaways

  • Community water fluoridation is a safe and effective way to prevent dental decay.
  • Water fluoridation has been used in communities throughout Canada for over 50 years.
  • Current science supports the safety and effectiveness of water fluoridation.

Community water fluoridation (CWF) is a safe and effective means of preventing dental decay. It is an important public health measure that improves the oral health of Ontarians. Our position is based on decades’ worth of overwhelming scientific evidence. It is driven by our mission to promote optimal oral health.

As of 2017, 71 per cent of Ontarians benefit from fluoridated water1.

How it Began

The connection between fluoride and dental health began to be explored in the early twentieth century. By the 1950s, communities across North America had begun fluoridating their water supplies. Ontario was one of the first places in the world to introduce CWF as a public health initiative to reduce tooth decay.

The first Canadian community water fluoridation trials began in Brantford, Ontario in 1945.

How it Works

Fluoride is a mineral found in soil, water (both fresh and salt) and various foods. It works by making the outer layer of teeth stronger and less likely to get cavities. Fluoride can also prevent or even reverse tooth decay that has started. You can buy fluoride toothpaste and rinses, or get professional fluoride products (e.g. gels, rinses and supplements) from your dentist.

Water fluoridation can reduce tooth decay in children’s primary teeth by up to 60 per cent, and in their permanent teeth by up to 35 per cent. Adults experience a 20 to 40 per cent reduction in tooth decay from lifelong exposure to water fluoridation.2

Fluoride is added to public drinking water to protect all members of the community from tooth decay, no matter their age, income or education. Community Water Fluoridation is an inexpensive, safe and proven way to way to reduce cavities. Canadian studies have shown that for every $1 invested, approximately $43 is saved in reduced dental and other costs.3

Why it’s Safe

Fluoridation’s positive impact and safety are supported by hundreds of studies and nearly 70 years of experience. National and international health organizations continue to endorse water fluoridation. Its safety and effectiveness are frequently studied and continues to be supported by current science. Canadian and international studies agree that water that was fluoridated at optimum levels does not cause adverse health effects.

Any decision about CWF should be based on facts. Listen to medical officers of health, public health doctors and other scientific and medical experts.

We understand you may have more questions about fluoride. Here are some helpful resources:


1 Public Health Agency of Canada.
The State of Community Water Fluoridation across Canada (Table 3) 2017

2 Ontario Ministry of Health.
Oral Health – More Than Just Cavities: A Report by Ontario’s Chief Medical Officer of Health
April 2012

3 CADTH Technology Review.
Community Water Fluoridation Programs: A Health Technology Assessment — Budget Impact Analysis
February 2019