What is Fluoride? And Why is it in the Public Water Supply?

Fluoride is a mineral that occurs naturally in rocks and soil. Via rocks and soil, it leeches into ground water.

So, fluoride was already in bodies of water like rivers, oceans and lakes before we decided to harness it for public health use. The reason fluoride is so good for preventing tooth decay is two-fold. First, fluoride makes teeth more resistant to demineralization, or enamel loss. Second, it speeds up the body’s remineralization, or enamel repair, process. Like most things, there is a certain ppm ratio of fluoride to water that makes fluoride both safe and effective at preventing tooth decay. That’s what the fluoridation of city water supplies was supposed to achieve.

How did we figure out fluoride was good for teeth? In the 1930’s, the CDC studied children in places with water supplies that were naturally fluoridated. They found that these kids displayed significantly less signs of tooth decay than kids in places without fluoridated water. This was an important discovery, because back then the overwhelming majority of children and adults experienced tooth decay, toothaches and cavities.

For those of you wondering why the government suddenly decided to become benevolent – they didn’t. Adding fluoride to public water supplies doesn’t just keep our smiles healthy – it saves them a bunch of money. It costs a little over $1 per year per person to keep water supplies fluoridated properly. But the return on investment for that is exponential, with a yearly savings of up to $38 per person on dental costs.

However, now that at-home dental technology like fluoridated toothpaste, electric toothbrushes and therapeutic mouthwashes are more common, even countries without fluoridated water are seeing huge drops in cavity rates in children. This is also due to easier access to dental care for regular dental cleanings. Studies also show questionable efficacy of fluoridated water in protecting adult teeth. Both these developments caused the US Public Health Service to lower their recommended fluoridation levels for the first time since the 1950’s. So, while two of the very few things medical science can agree on is that fluoride is safe and that fluoridated water prevents cavities in kids, ongoing research and global advances in quality of life might start to change the way we get our recommended amount of fluoride.