Fluoride is present to some extent in all water, food and beverages, but the concentrations of natural fluoride in water vary widely from community to community.

Many communities choose to adjust the fluoride concentration in the water supply to a level beneficial to reduce tooth decay and promote good oral health. This practice is known as community water fluoridation. Given the dramatic decline in tooth decay during the past 65 years, the Centers for Disease Control and Prevention named water fluoridation one of 10 Great Public Health Interventions of the 20th Century.

The latest data show that in 2008, 72 percent of the U.S. population on public water systems, or 195 million people, had access to optimally fluoridated water.  Approximately 89 percent of the population in Wisconsin on public water supplies receives the benefit of appropriate levels of fluoride.