Low levels of Fluoride are naturally present in most mineral waters and are also often added to potable water to reduce the level of tooth decay.
Our view is that small amounts of Fluoride, released slowly over time, can have a therapeutic benefit of enhanced resistance to acid attack such as provided in BioMin™ F toothpaste. However, we accept that excessive levels of Fluoride can create health risks resulting in Fluorosis; typically indicated by a permanent mottled appearance to the tooth (although there can be other causes).
The exact mechanisms behind Fluorosis are not widely understood. It is known that in the presence of excessive Fluoride, Fluorite (CaF2) crystals can form rather than forming Fluoridated Apatite or Fluorapatite. We believe that applying additional Fluoride should be a matter of choice and recognise some are averse to the concept of introducing additional fluoride into the body.
For this reason we have developed BioMin™ C – a Fluoride-free version which delivers high levels of new apatite to tooth surfaces but clearly cannot develop more resistant Fluorapatite.
Fluorapatite is more resistant to acid than Hydroxyapatite, hence it gives greater protection against acid attack. The Fluoride ion fits in the centre of the triangle formed by the Ca (II) in the apatite lattice. The Hydroxyl ion is slightly larger and is displaced above the Ca (II) triangle which distorts the crystal structure therefore making the apatite less stable.
The minimum therapeutic concentration of Fluoride is about 1ppm (the same level typically added to drinking water). At this concentration, direct Fluorapatite formation is thought to occur, rather than forming octacalcium phosphate which subsequently converts to apatite.
Conventional toothpastes use a soluble Fluoride, which after brushing onto the teeth is rapidly washed away. The Fluoride concentration in the saliva falls exponentially with time. In contrast, BioMin™ F technology uses a much lower level of Fluoride that is delivered in a controlled manner over a period of 12 hours after brushing.
The image below shows the soluble Fluoride decrease (light blue dots) over time compared to the Fluoride release of BioMin™ F toothpaste over the same time period (green line).
This view is very much in line with that of world-renowned caries expert, Prof Ten Cate (Netherlands), who states:
Low Concentrations of Fluoride have a beneficial effect on enamel and dentine remineralisation. After fluoride treatments such as topical applications rinses or dentifrices, salivary Fluoride concentrations decrease exponentially in a biphasic manner to insignificant concentrations within a few hours.
For treatments to be effective longer than the brushing and salivary clearance, Fluoride needs to be deposited and slowly released.