For decades, oral healthcare has been focused on the effects of fluoride and how it prevents enamel demineralisation caused by acidic food, drink and plaque because it helps to reinforce and strengthen enamel.
This is because when fluoride interacts with enamel hydroxyapatite, it results in fluorapatite, which is less soluble and more mechanically resistant.
Indeed, much scientific evidence supports the positive effect that fluoride has on oral health, and subsequently a lot of oral care products containing fluoride have been patented. In some countries, drinking water has also been enriched with fluoride.
However, fluoride is not essential for human growth and its content in the body is not under physiological control. Once absorbed, for example, fluoride is rapidly distributed throughout the body and is retained only in calcified tissues. As a result, dangerous health conditions have been linked to the daily intake of fluoride and many studies have proven that there are actually high risks associated with fluoride, in particular for children (fluorosis) and for old people (bone disease).
Despite these findings, fluoride continues to be widely used in oral care products to prevent enamel surface demineralisation.
Hydroxyapatite has many excellent properties, such as being able to bond directly to bone, and is widely considered to be the main synthetic biomaterial of bone filler and bone substitute in surgery.
Recently there have been exciting new developments regarding biomimetic hydroxyapatite microparticles. These new hydroxyapatite microparticles mimic natural hydroxyapatite in composition, structure and morphology, they are also surface nanostructured. This means that they have a high level of chemical reactivity and biological activity, which allows them to bind chemically to enamel and dentine apatite, thereby producing a protective biomimetic coating on the enamel surface. This enamel coating prevents the demineralisation of teeth, fights the build-up of plaque and seals dentine tubules to cancel out hypersensitivity.
Unlike fluoride remineralisation, which is based mainly on surface enamel apatite modification, the biomimetic hydroxyapatite remineralisation forms a new coating that fills in scratches on the surface of teeth, covers the enamel structure and safeguards the enamel against attacks from acid and bacteria.
This new mineral apatite deposition represents not only an innovative approach to enamel demineralisation, but also the first real enamel remineralising and repairing process.