Fluoride. Why does the dentist love it?

Fluoride is a variation of the element Fluorine. In this form it is the 13th most common element on Earth. It occurs naturally in the soil, sea water and fresh water (long before humans purposely added it to our drinking supply) and in many plants and animals, including in human body and skeletal tissues (and yes, teeth!) 

But is it harmful? Like many things in life, too much can be harmful. When used at recommended levels, the benefits far outweigh potential harms. At levels found in Sydney drinking water, you would need to consume  136L of water to ingest a toxic dose. Importantly though, young kids should be taught to spit-out toothpaste at an early age, as ingestion of fluoride in these higher-concentrations is not ideal. This is why kids toothpaste has low levels of fluoride to begin with. 

So how does it help teeth?

  • During formation: In low quantities, fluoride is ingested and then incorporated into the tooth enamel during formation. Enamel is naturally made up of hydroxyapatite (microscopic prism crystals) but in the presence of fluoride, fluorapatite is formed instead, which is less vulnerable to decay. 
  • Protection from decay: When a tooth is exposed to fluoride, a reservoir of calcium fluoride is formed on the tooth surface which can be released for remineralisation. 
  • Remineralisation in early decay: As tooth structure demineralises from acidic sources and decay-causing bacteria, fluoride is taken up by the demineralised enamel as fluorapatite. It essentially hardens the weakened enamel in the early stages. 
  • Antibacterial action: Fluoride has been shown to interfere with the metabolic activity and growth of decay-causing micro-organisms. 

As you can see, the benefits in keeping your teeth healthy for life, far outweigh any potential detriments when used appropriately!