UN Treaty Calls for Dental Amalgam Reduction

Laird Harrison

January 25, 2013

An international treaty drafted earlier this month calls for phasing out dental amalgam to reduce mercury pollution.

The Minamata Convention, negotiated under the auspices of the United Nations Environmental Programme (UNEP), sets a deadline for banning the manufacture, import, and export of several categories of products containing mercury, such as batteries, light bulbs, and cosmetics, by 2020.

However, it excludes dental amalgam from this list, instead laying out measures that should be used to reduce its use. It does not set a timetable and leaves much to the discretion of individual countries.

"We were very happy in the end," Christopher Fox, DMD, DMSc, executive director of the International & American Associations for Dental Research (IADR), told Medscape Medical News. "We were very pleased that they gave deference to science-based policy."

Although the text has not been finalized, participants from 137 countries agreed in principle to the draft document on January 19. Individual countries must ratify the treaty before it becomes legally binding, Dr. Fox said.

The final report will be adopted and opened for signature in a conference held this October in Kumamoto/Minimata, Japan.

Goals for Amalgam

The draft document has not been released to the public, but Dr. Fox verified the accuracy of a January 21 report on it published in the Earth Negotiations Bulletin, which is put out by the International Institute for Sustainable Development, a nonprofit environmental group based in Winnipeg, Canada.

According to that report, the signatories must agree to take at least 2 of the following steps, subject to their individual circumstances:

  • setting national objectives aiming at dental caries prevention and health promotion, thereby minimizing the need for dental restoration;

  • setting national objectives aiming at minimizing the use of dental amalgam;

  • promoting the use of cost-effective and clinically effective mercury-free alternatives for dental restoration;

  • promoting research and development of quality mercury-free materials for dental restoration;

  • encouraging representative professional organizations and dental schools to educate and train dental professionals and students on the use of mercury-free dental restoration alternatives and on promoting best management practices;

  • discouraging insurance policies and programs that favor dental amalgam use over mercury-free dental restoration;

  • encouraging insurance policies and programs that favor the use of quality alternatives to dental amalgam for dental restoration;

  • restricting the use of dental amalgam to its encapsulated form; and

  • promoting the use of best environmental practices in dental facilities to reduce releases of mercury and mercury compounds to water and land.

The report in the Earth Negotiations Bulletin called the negotiations on dental amalgam "divisive," with Switzerland and Norway pushing for an outright ban on the substance. Some groups claimed that it harms patients and professionals when used in fillings, and others argued that it is a safe and effective way to treat cavities. Participants also clashed about the viability of alternatives, according to the report.

The American Dental Association participated through the World Dental Federation and added its voice to those arguing that there should be no timetable for phasing out dental amalgam.

The World Dental Federation, World Health Organization, and IADR argued that the best way to phase out amalgam is to reduce the need for it by promoting oral health. "We need an increased emphasis on prevention," said Dr. Fox. "The best dental restoration is no dental restoration."

Beyond that, the IADR called for more resources to develop alternative dental materials. In a December meeting, the IADR, World Health Organization, UNEP, and other international groups noted concerns about health hazards from bisphenol A in composite resins as a reason giving urgency to the search for alternatives.

Dental amalgam was not the major focus of the January UNEP meeting; it only accounts for about 8% of the overall use of mercury, said Dr. Fox.

Cremation of patients with amalgam restorations causes about 1% to 2% of mercury air pollution, he said. A bigger concern is mercury in wastewater from dental operatories, and Dr. Fox speculated that the treaty might push the US Environmental Protection Agency toward requiring amalgam separators.

"We also recognize that we do have a responsibility to the environment," Daniel M. Meyer, DDS, senior vice president for science/professional affairs at the American Dental Association, told Medscape Medical News. "The House of Delegates passed a resolution to work with the [Environmental Protection Agency] to establish appropriate regulations."

The Minamata Convention derives its name from a Japanese city devastated by mercury pollution.

Fifth Session of the Intergovernmental Negotiating Committee to Prepare a Global Legally Binding Instrument on Mercury, January 13-19, 2013. Geneva, Switzerland.