Toxic dental filling harms health, environment

More than fifty per cent of dentists in Bangladesh use amalgam in dental fillings notwithstanding its negative impacts on human health and the environment. Most of them do not even let patients know amalgam contains mercury.
"They do it for quick and easy profits, and then pass the bill for damages on to the rest of us - damages of the health, as well as to the environment," said Charles G. Brown, President of the World Alliance for Mercury-Free Dentistry.
He mentioned that a new global, legally binding treaty on mercury, styled 'Minamata Convention on Mercury', has been signed and Bangladesh is a signatory. He said dental amalgam is neither appropriate nor practical in the 21st century and insisted that Bangladesh should go by the agreed rules.
According to experts, mercury dental amalgam costs the country some US$ 1.4 billion a year. It is calculated that the Tk 500 inexpensive mercury amalgam has its hidden health cost of Tk 8000 to Tk 300,000 per person. Thus, this old practice of dental treatment imposes an aggregate burden of around US$ 1.40 billion on the Bangladesh health and environment sectors, said another ecologist and mercury expert, Dr. Hossain Shahriar.
Amalgam is a dental filling material used to fill cavities caused by tooth decay. It is a mixture of metals, consisting of 50 % liquid mercury and a powdered alloy composed of silver, tin, and copper. Mercury is used to bind the alloy particles together into a strong, durable, and solid filling. Mercury's unique properties make it an important component of dental amalgam that contributes to its durability. Such, toxic dental stuffing is also known as "silver fillings" because of their silver-like appearance.
There are several different chemical forms of mercury: elemental mercury, inorganic mercury, and methyl mercury. The form of mercury associated with dental amalgam is elemental mercury, which releases mercury vapour. The form of mercury found in fish is methyl mercury, a type of organic mercury. Mercury vapour is mainly absorbed by the lungs. Methyl mercury is mainly absorbed through the digestive tract.
According to Charles G. Brown, Mercury amalgam fillings are the main source of mercury exposure and nearly 200 million people in the USA alone have them. These fillings continuously release mercury as a toxic vapour and as much as 80 percent of the vapour enters the body.  Amalgam continues to release mercury after it is implanted in the body, and can even cross the placenta to reach unborn babies in chain effects.
Sooner or later, most of the mercury from amalgam ends up in air, soil, and water via numerous unsound pathways. Once in the environment, amalgam can convert to methyl mercury, contaminate fish, and even wind up on dinner plates.
Charles G. Brown, also National Counsel, Consumers for Dental Choice, talked to this correspondent on the sidelines of a conference-South Asian Summit for Mercury-Free Dentistry - held recently in Dhaka. Environment and Social Development Organization (ESDO) organised the meet in association with the Asian Centre for Environmental Health and World Alliance for Mercury-Free Dentistry.
According to Brown, the problems with mercury fillings are twofold. First, these fillings are very sensitive to any kind of stimulations like eating, drinking, brushing your teeth, grinding your teeth, and chewing gum. And these actions can release mercury. These mercury vapours readily pass through cell membranes, across the blood-brain barrier, where it causes immunological, neurological, and even psychological, problems. Children and foetuses, whose brains are still developing, are most at risk, but really anyone can be impacted.
Even the U.S. Food and Drug Administration concede that the developing neurological systems of children and foetuses are more susceptible to "the neurotoxic effects of mercury vapour". And there is no evidence that amalgam is safe for these populations.
Second, dental mercury is the number-one source of mercury in wastewater, so dentists are handing the clean-up bill for their pollution to taxpayers and water ratepayers. And this mercury ends up in the food supply, where it can cause continued damage to public health when they eat fish and other contaminated seafood. An estimated 362 tonnes of dental mercury is used annually worldwide, causing a significant environmental burden.
Citing a survey, Zogby International poll on 2,590 US adults, Brown said about 76 percent of consumers do not know that amalgam is mainly mercury. But once they are informed, 77 percent of people do not want mercury fillings - and they were even willing to pay more to avoid this unnecessary source of mercury exposure.
According to sources, half of Australian dentists have stopped using amalgam, and the proportion of fillings undertaken using mercury amalgam had fallen from 68 percent in 1983 to 30 percent by the end of the 1990's. The situation has improved further in recent days. If the public were fully informed of the composition of mercury amalgam fillings and dentists were aware of the negative environmental impact and health hazards of this material, then this proportion would drop even further.
Although in Bangladesh young dentists are tending to move away from the use of mercury amalgams, the profession as a whole has been resistant to adopting cost-effective alternative materials. Despite the odds, the global consensus on the anti-mercury movement is gaining momentum. Already, Denmark, Sweden and Norway have banned dental amalgam (a specific exception can be granted for individual cases). Canada, Italy and Australia have taken steps to reduce amalgam use.
The 47 nations of the Council of Europe also passed a resolution calling on the nations to start "restricting or prohibiting the use of amalgams as dental fillings." The legal step was taken through explaining that "amalgams are the prime source of exposure to mercury for developed countries. These toxins are also affecting embryos, foetuses (through the placenta) and children (through breastfeeding)."
"The world has come to ask Dentsply to stop making amalgam, and dentist to stop using amalgam to protect our health and environment," said Charlie Brown. The World Alliance for Mercury-Free Dentistry he leads works to phase out amalgam throughout the world and has recently focused on Dentsply because the company is the second-leading manufacturer of the substance. Dental mercury accounts for 10 percent of mercury in the environment. And it comes to about 313 to 411 tonnes. "That's a lot," he said.
The wave of anti-mercury movement has also inspired doctors and professionals in Bangladesh. A good number of experts, doctors, specialists and professionals attended the ESDO programme both in Dhaka and Chittagong and discussed the adverse impacts of mercury fillings and feasible, inexpensive alternatives. They also conferred about improving the dental school curriculum and informing the young dental professionals about the negative impacts of mercury amalgam on health and the environment and to take a proactive approach.
"The approach is to see the end of amalgam in the environment," said Charlie Brown, the president of the World Alliance for Mercury-Free Dentistry, a multinational group that lobbies to ban the use of mercury in dentistry.
The enthusiasm among the young doctors, professionals indicate that the move against silver fillings is also getting momentum in Bangladesh. "We are getting very positive responses from young dentists", said Brown while Talking to The Financial Express.
Charlie Brown noted that Bangladesh is a densely populated, large delta and disaster-prone country so protection of the people and the environment is urgently needed.  He appreciated the government initiatives to ratify the "Minamata Convention on Mercury" and said that they must take measures to phase out amalgam as soon as possible.
He prescribes that Bangladesh needs to take at least two of these phase-down steps promoting mercury-free alternatives, changing dental school curriculum and re-training dentists, and encouraging insurance programs to favour mercury-free dental restorations over amalgam.
"Though we did not yet achieve anything towards the phasing-out of amalgam, we made good progress and had a good response which we have never achieved before," said Dr. Hossain Shahriar, a crusader in Bangladesh against mercury, who is also the founder of ESDO.
"Phase-out of mercury use in dentistry will benefit people and the environment.  These would include such benefits as reduced health costs, reduced environmental effects, additional jobs created," said Dr. Shahriar.  

Referring to a global finding and a recent study by Environment and Social Development Organization -ESDO - that the cost of dental amalgam is very high, Dr. Shahriar referred to the study outcome that while most dental professionals charge lower prices for amalgam fillings than for mercury-free alternatives, when factoring in "external" environmental and societal costs, amalgam is a higher-priced dental material by far.
Ultimately, society pays for mercury releases related to amalgam use through additional pollution-control costs, the loss of common (public-owned) resources, and the health effects associated with mercury releases and contamination.
According to the study, the average expense for a mercury filling is 800 taka. However, the associated health and environmental cost from the dental mercury pollution will be Tk 8000 to 3 lac per person. In general for Bangladesh, this is a burden of around $1.40 billion per year.
The writer is Special Correspondent of the FE. He can be reached at: mzrbd@yahoo.com