Sir, imagine my surprise when in recent conversation with my dentist I discovered that my mouth is contaminated by a high concentration of 'hydroxyapatite'. Since learning this shocking information I have spent a significant amount of time browsing Internet chat rooms and in conversation down the pub and would like to present the findings of my research for your consideration.

Hydroxyapatite is a terrifying sounding complex crystalline mineral which has the chemical name Ca10(PO4)6(OH)2. As if this weren't bad enough you can see its ingredients include 'phosphate' and 'hydrogen'. Hydrogen is known for being a highly flammable gas, responsible for the Hindenberg disaster. Phosphate is an industrial chemical used in fertiliser and can also be used to make explosives! Further research has led me to discover that hydroxyapatite is commonly found in the mouths of monkeys, pigs and (worst of all) rats!

There has never been any research into the safety of this chemical in our mouths. As you know, a 'randomised control trial' is well recognised as a gold standard research method. I think it is telling that there has never been a single randomised control trial to demonstrate the safety of hydroxyapatite. There are no regular measurements made of the levels of hydroxyapatite found in urine, blood or nails. However, what we do know though is that it can accumulate in bones, sometimes making up to 70% of bone mass by weight. This seems like an awfully high percentage.

Worse still, there is no standardisation of the oral dose individuals are exposed to. This can vary massively, even between members of the same family. It seems that people subject to high levels of sugary and acidic foods and with low levels of oral hygiene are much safer as they have significantly reduced oral quantities of hydroxyapatite. This is contrary to 'traditional' oral health advice. Some would say that this advice is outdated.

Aside from the chemical dangers of hydroxyapatite there is also the physical danger. Studies have shown that it is extremely hard and when teeth covered in hydroxyapatite are pressed into soft tissue with force (for example, the arm of a colleague), significant trauma can be caused.

Unfortunately, government officials and dental professionals have put a great deal of their credibility on the line defending hydroxyapatite, demonstrated by the fact that most modern dentistry is aimed at protecting and preserving this potentially deadly mineral. This means it will be very difficult for them to speak honestly and openly about the issue.

After consideration of the evidence this author suggests precautionary removal of hydroxyapatite from the oral environment. The safest way of achieving this is a full dental clearance and provision of complete dentures as this avoids aerosolisation and environmental pollution. However, an untested but more conservative approach could include removal of the layer hydroxyapatite from all teeth and replacement with a layer of hygienic and chemically stable porcelain.

My advice to patients would be to not be disheartened if your dentist looks confused or even incredulous when you discuss this with them. It is important to remember that they are unlikely to be as well informed as you. This is because health professionals rely on published studies in peer-reviewed journals for information to inform their practice. This leaves them with limited experience of the real world and of internet search engine use.

Important note to readers

This content has been created for the entertainment of readers in the spirit of seasonal good humour and, on the whole, possesses not an ounce of truth. All persons, products, URLs and email addresses mentioned have been invented by the BDJ Editorial Team.

1. Milton Keynes