Hydroxyapatite has become one of the most exciting ingredients in modern oral care, largely because it works with the natural mineral structure of our teeth. But what does it actually mean when we say that hydroxyapatite can remineralise enamel?
What is enamel made from?
Tooth enamel is the hard outer layer that protects our teeth. Around 97% of enamel by weight is mineral, with its main component being hydroxyapatite – a crystalline form of calcium and phosphate.
Instead of relying on an ingredient completely foreign to the tooth, hydroxyapatite provides a mineral closely related to the material enamel is naturally made from. This is why it is often described as a “biomimetic” ingredient.
How does enamel lose minerals?
Throughout the day, our enamel naturally moves through periods of demineralisation and remineralisation.
When bacteria in dental plaque metabolise sugars and carbohydrates, acids are produced. Acidic foods and drinks can also lower the pH around our teeth. When the environment becomes acidic enough, minerals including calcium and phosphate can begin to dissolve out of the enamel.
In the early stages, this does not necessarily mean there is a physical hole or cavity. Instead, the enamel becomes more porous as microscopic areas of mineral are lost.
This is where remineralisation becomes important.
How hydroxyapatite supports remineralisation
When you brush with a hydroxyapatite toothpaste, hydroxyapatite particles are delivered directly to the enamel surface.
These particles can deposit onto areas where mineral has been lost and provide a local source of calcium and phosphate. Alongside the minerals already present in saliva, this can support the natural remineralisation process and encourage mineral to be redeposited into weakened areas of enamel.
Over time, repeated mineral deposition can help make the enamel surface denser, smoother and more resistant to further mineral loss.
It is important to distinguish this from rebuilding a tooth that already has a physical cavity. Toothpaste cannot replace missing tooth structure once enamel has collapsed. Hydroxyapatite is most relevant to the early stages of enamel demineralisation, before a cavity has formed.
Understanding the image
The accompanying image shows the process in four stages:
1. Healthy enamel: Mineral crystals are densely packed, creating a strong enamel surface.
2. Demineralisation: Acid causes calcium and phosphate to leave the enamel, creating microscopic spaces within its mineral structure.
3. Hydroxyapatite deposition: Hydroxyapatite particles from toothpaste settle onto and within these porous areas, providing tooth-like calcium-phosphate mineral.
4. Remineralised enamel: Mineral is redeposited into weakened areas, helping restore a denser and smoother enamel surface.
Why we use hydroxyapatite at Dimples
At Dimples, we use micro-hydroxyapatite because we wanted a biocompatible ingredient that works with the natural mineral composition of teeth.
Used alongside good brushing, a tooth-friendly diet, healthy saliva and regular dental care, hydroxyapatite offers a simple way to support one of the mouth’s own protective processes: remineralisation.
Visit our shop to try our hydroxyapatite toothpaste.