Fluoride is a mineral found in soil and various foods. It 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.  https://www.cda-adc.ca/en/oral_health/cfyt/dental_care_children/fluoride.asp.  Community water fluoridation is an important investment for all age groups, particularly children. Scientific evidence continues to support the health promoting effects of fluoridating drinking water which is a cost-effective population-health method of preventing tooth decay. (http://www.firstvisitfirsttooth.ca/),  https://www.cda-adc.ca/en/oral_health/cfyt/dental_care_children/fluoride.asp