But there's a growing movement of people in St. Joseph who think it's bad for you.
An activist group, the Fluoride Action Network (FAN), is organizing to push city leaders to take fluoride out of the water.
"The more fluoride you have in your system, the worse it is for your teeth," said FAN organizer Richard Taylor. "The fact is that most of western European countries do not fluoridate their water. Their rate of dental problems is the same as ours."
Taylor says Americans have been brainwashed to believe fluoride is good for us. However, Taylor says exposure to fluoride can cause cancer, stunt growth in adolescent boys and weaken bones as you age.
"There's about 100 studies, most of which were done in China, India and Iran, with both animal and human subjects. They indicate the higher the fluoride content in the water the lower the IQ. We're talking in the range of 5-10 IQ points," Taylor said.
Local health experts disagree and say Fluoride is beneficial, especially for those in lower socio-economic classes.
"There are a lot of individuals that can't afford to go to a dentist on a regular basis and they couldn't go if then needed a fluoride treatment they wouldn't be able to afford the fluoride treatment," said Debra Bradley, Director for the City of St. Joseph Health Department.
Thursday night Taylor showed others what he says are the dangers of fluoride. He wants to start a petition drive to eliminate fluorine additives from our water supply.
He had a receptive audience.
"The fluoride in the water, after learning tonight, is actually a chemical waste that chemical companies are selling to America to put in our water," said Tracy Pankau, who came to learn more about the dangers of fluoride.
"If you talk to some politicians, they pretty much stay away from this issue," Taylor said. "They say there's too many powerful forces that are mitigating against it."
Last year, the City of Smithville stopped adding fluoride to its water.
In 2012, St. Joseph reduced the amount of fluoride in its water from one part per million to .7 parts per million.