Fluoride toothpaste is efficacious in preventing dental caries, but its effectiveness depends on frequency of use by persons or their caregivers. In contrast, water fluoridation reaches all residents of communities and generally is not dependent on individual behavior.

Although early studies focused mostly on children, water fluoridation also is effective in preventing dental caries among adults. Fluoridation reduces enamel caries in adults by 20%-40% (16) and prevents caries on the exposed root surfaces of teeth, a condition that particularly affects older adults.

Water fluoridation is especially beneficial for communities of low socioeconomic status (18). These communities have a disproportionate burden of dental caries and have less access than higher income communities to dental-care services and other sources of fluoride. Water fluoridation may help reduce such dental health disparities.

"Seventy years of research, thousands of studies and the experience of more than 210 million Americans tell us that water fluoridation is effective in preventing cavities and is safe for children and adults," according to the American Dental Association.

“In just eight years after fluoridation ended in 2011, the need for intravenous antibiotic therapy by children to avoid death by infection rose 700 per cent at the Alberta Children’s Hospital.”

According to Dickinson, a recent University of Alberta study shows that for children under five years old, the rate of dental treatments under anesthesia doubled from 22 per 100,000 in 2010-11 to 45 per 100,000 in 2018-19.

For kids aged six to 11, the rates rose from 14 per 100,000 to 19 per 100,000.

The rates stayed the same over that time period in Edmonton, where the water is fluoridated.

“Since fluoridation ceased, the cavities (holes) in teeth are more numerous and larger. These might require filling or extractions,” Dickinson said.

“They are occurring earlier in a child’s life so that treatment can require general anesthesia.”

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Based on 2013 estimated costs ($324 million), net savings (savings minus costs) from fluoridation systems were estimated to be $6,469 million and the estimated return on investment, 20.0.

To see the potential impact of stopping water fluoridation, Yancoskie points to locations that have been previously studied.

"The two areas that were studied were Juneau, Alaska, and Alberta, Canada, and when they removed that fluoride, the rates of cavities increased dramatically in the children of those populations," he said.