Fluoride is the compound made when fluorine reacts with something, but we wondered, why is flouride good for teeth? On its own fluorine is a gaseous substance that is extremely toxic and reactive. But for some reason mixing it with sodium, to create sodium fluoride, is actually beneficial for our teeth. We need to understand some basic chemistry to understand why fluoride is good for teeth.
The Discovery of Fluoride
Fluoride doesn’t have to be mixed with sodium to be good for our teeth, it can be any compound as long as it is safe and releases fluoride ions. It is the ions that are good for us and this fact was discovered completely by accident. In 1901 dentist Frederick McKay began looking at patients in Colorado springs. He noticed that even though peoples teeth were covered in brown stains, they had a surprising resistance to tooth decay. This was the first time this had ever been observed and so McKay and others set out to research.
30 years later, they had the answer, fluoride. It turned out that the water in the area was stuffed full of naturally occurring fluoride, this caused a resistance to decay, but due to the incredibly high amounts in the water those nasty dark spots came with the healthy teeth. The correct concentrations of fluoride were soon discovered and it became clear how much was needed for healthy, spotless teeth. This was put in place in Michigan and over the next few years, reports of cavities dropped by a whopping 60% but there was still uncertainty as to how this even worked.
How Flouride Works
The way fluoride works was finally discovered in 1962 when scientists discovered that enamel contains the chemical hydroxapatite, this is broken down into phosphorus and calcium when interacting with bacteria, but when fluoride is present it reacts with the excess phosphorus and calcium to make fluorapatite which then joins back to the tooth, reinforcing the enamel rather than wearing it away.