You may (or may not) be aware that the World Health Organisation (WHO) convened a panel in November 2009 to look into the health and environmental concerns relating to the use of dental amalgam. The findings were published in a 57 page report entitled Future Use of Materials for Dental Restoration in 2010, a summary of which is provided at the end of this article.
But first, in order to understand the implications of the report for the future of dentistry, it is important to look back and understand where we are and how we got here. I know that I spent a total of seven years training at two of the best dental schools in the world, actually doing a Master’s degree in Restorative Dentistry at the University of Michigan and the subject of the toxicity of amalgam was never mentioned other than to be summarily dismissed!
Amalgam: The first 200 years
Dental amalgam was first created nearly 2 centuries ago by a Frenchman, August Taveau, who shaved silver coins and mixed the filings with mercury. Two French brothers – the Crawcours – first brought this innovation to England and then to America when they emigrated there in 1833.
At the time there were no dental schools and there were two groups of people providing dental services. One were unregulated and untrained tradesmen and particularly barbers who had the advantage of having reclining chairs, and the other group were gentleman physician-surgeons.
Things, frankly, weren’t fantastic when the Crawcour brothers began peddling their new filling material under the grand title ofRoyal Mineral Succedaneum since lead, cork, tin and pine resin were all being used as filling materials for the masses along with gold for the wealthy.
The dangers of mercury as particularly evidenced in the hatting and mining industries were already well known at the time. And the first dental society, the American Society of Dental Surgeons (ASDS), was founded in 1840 on the basis of the physician-surgeons taking a stance against the use of amalgam which it regarded as being unethical.
However, the untrained and unregulated barber surgeons continued to cash in on the craze, and soon membership of the ASDS dwindled as physician members jumped ship until the society was disbanded just 16 years after its foundation. In fact, the derogatory term ‘quack’ (from quecksilber, the German word for mercury) was originally coined by the physicians to refer to the tradesmen who used amalgam fillings.
From the void created by the dissolution of the ASDS arose, phoenix-like, the American Dental Association (ADA) which was founded in 1859 and actively promoted the use of amalgam and for which it currently owns the patents (U.S. Patents 4018600 and 4078921).
This fracas was the ‘First Amalgam War’ and you have to ask yourself how it can be considered unethical to remove something today which it was unethical to place 180 years ago.
The “We’ve done it for a long time” argument
From its introduction to the present day, amalgam has never been subjected to any meaningful toxicological testing and has been ‘grandfathered in’ to the profession. One of the main and rather circular arguments used to defend this state of affairs by the ADA is that the safety of amalgam should not be disputed precisely because it has been in use for over 150 years.
However, the fact that we have been doing something plainly as inadvisable as inserting the third most toxic and second most deadly substance known to man into cavities in people’s teeth for nearly two centuries doesn’t make it right. Take, for example, slavery and bloodletting.
The human slave trade in one form or another has dogged the history of mankind for millennia (and still does with an estimated 27 million slaves worldwide) and some of the good people of the US resisted that change so vociferously they went to war with their brothers over it.
The theory of the four humors as propounded by the Ancient Greek physician, Hippocrates, became the central tenet of medical practice for over two thousand years. As such, bloodletting was the most common practice used to treat or prevent almost every disease and was still being recommended in respected medical textbooks as recently as 1923!
We have done a lot of foolhardy things when we didn’t know any better. We used asbestos in buildings, x-rayed children’s feet in shoe shops, and used DDT with abandon. Now, with the wisdom of hindsight we ask with incredulity “What were we thinking?”
The health effects of amalgam use
In 1974 the World Health Organisation stated that heavy metal toxicity was a major source of world disease and also determined in 1991 that the lion’s share of mercury exposure (65-90%) for most people comes from their dental amalgam fillings.
Mercury is unique in being a liquid metal that vaporises at room temperature. When mixed with the other toxic metals used in dental amalgam the fillings become galvanically active and this promotes the release of about 32 mcg of mercury vapour per filling per day.
This vapour is inhaled and approximately 80% is absorbed in the lungs from where it readily passes into the circulation and to the rest of the body. From there (depending upon a variety of factors) it can accumulate in any organ or system initiating or worsening a wide range of illnesses.
There is a delay of many months or even years in the appearance of symptoms known as ‘silent latency’ and this and the sheer number of different biochemical and neurological manifestations have confounded making the causative link.
The average filling contains 1 gm of mercury (about the same amount as in a thermometer) which is enough to contaminate a 20 acre lake to the point where warnings not to eat any fish caught would be issued. And it is well established that just 50% of the original mercury content of the amalgam filling remains after 7 years and just 20% after 20 years.
The harm that mercury does is cumulative and it is said to take just one atom of mercury to kill a cell. With the average filling emitting more atoms of mercury (120 trillion) per day than there are cells in the body, you may start to appreciate the effects of having an average number of amalgam fillings over a period of years or decades.
To make a bad situation a whole lot worse, high copper or non-gamma II amalgam was universally introduced in the 1970s and was supposed to overcome the problem with amalgam fillings expanding and cracking and breaking teeth. There is evidence to suggest that this amalgam – which contains 30 percent copper in the alloy powder – was known to form droplets of mercury on its surface when it was introduced.
This means that for the last 40 years the profession has been using amalgam that has been shown to emit 50 times the mercury vapour of the previous formulation - in addition to emitting large amounts of highly toxic copper. This one factor I believe may account for the stratospheric increase in chronic and serious illnesses including the ‘mysterious’, autoimmune and fatiguing syndromes such as CFS and fibromyalgia in recent decades.
In addition, placing any other metals in the mouth – particularly gold crowns and especially if placed over an amalgam ‘core’ – has been shown to compound the problem of mercury emission by a factor of 20 or more.
Recent studies have established that amalgam isn’t any better than the alternatives – it’s just what everyone is familiar with. I know that in my private practice, probably half of my work load related to teeth that had cracked or fractured as a result of amalgam fillings placed decades previously. Indeed, I have been a victim of this myself having had no fewer than 7 molar teeth crack and devitalise from mostly modest sized occlusal amalgam fillings.
The environmental effects of amalgam use
In addition to the devastating health effects of mercury toxicity upon the individual, the use of amalgam by the dental profession is a major source of environmental mercury. This is an issue because even small amounts of elemental mercury are converted by algae and microbes in the soil and waterways into organic mercury which is at least 100 times more toxic. This form is also very persistent and bioconcentrates and bioaccumulates up the food chain devastating our ocean ecosystems.
In the UK alone, over 7 tonnes of mercury from dental amalgam waste are discharged every year into the environment in one form or another, with a further 12 tonnes per annum being sent for recycling or disposed of as clinical waste. The WHO report estimates that globally dentistry may be responsible for releasing up to 340 tonnes of mercury into the environment annually.
The use of dental amalgam is thought to account for about one-third of the mercury in the sewage system from dental surgery waste and the combined medical and dental uses of mercury account for over half of the total mercury environmental contamination.
Indirect means by which the use of amalgam contributes to the total amount of environmental mercury include the fact that individuals with amalgam restorations excrete mercury daily in their bodily wastes over a lifetime. Also, when we reach the end of our earthly sojourn the mercury in our fillings and that has accumulated in our bodies is either vaporised into the environment in a crematorium or, if we are buried, leaches into the ground water and soil.
Continued in WHO Report: Update for Dentists 2