Teeth are primarily made up of dentine (inside) and the particularly hard enamel (outside).
Enamel in particular is made up almost exclusively of hydroxyapatite, Ca 5 (PO 4) 3 (OH).Enamel is comprised of needle-like hydroxyapatite crystallites that are bundled in parallel ordered prisms. This special microstructure makes enamel the hardest substance in the human body.
In summary, it can be said that teeth are hierarchical biocomposites with special properties:
- Hardness
- Fracture strength
- Self-repair mechanism by means of remineralisation from saliva
The following may also interest you:

Hydroxyapatite and BioHAP for the teeth
Hydroxyapatite is the hardest substance in the body and essential for healthy teeth. Find out how BioHAP can help keep your teeth healthy.

Caries: How to protect your teeth
Caries is one of the most common diseases in the world. Find out more about the caries and its causes.

Inflammation of the gums: Gingivitis or periodontitis?
More than 50% of adults suffer from gum inflammation. Read here about the causes and how you can avoid gingivitis and periodontitis.