International Association for Dental Research Policy and Position Statements on the Safety of Dental Amalgam

During the 97th General Session and Exhibition of the International Association for Dental Research (IADR), the IADR Council adopted policy and position statements on the safety of dental amalgam (American Association for Dental Research [AADR] 2019). The policy development process is overseen by the IADR Science Information Committee. While recognizing its global audience, the IADR Science Information Committee policy development process is identical to that of the IADR’s American division (AADR) and has been described (Ajiboye et al. 2018). The policy statement on the safety of dental amalgam is a succinct affirmation of the association’s evidence-based assessment, whereas the position statement is a fuller review of the scientific evidence. These statements were timely for the Third Conference of the Parties to the Minamata Convention on Mercury, an international treaty aimed at reducing global mercury pollution caused by human activity. In 2010, the United Nations Environmental Program estimated that dental amalgam contributed 21% to 32% and 9% to 13% of overall air and surface water emissions, respectively, in Europe. However, the total contribution of dental amalgam to mercury pollution is unknown and likely varies by region depending on a number of factors, such as other sources of mercury pollution, prevalence of use of dental amalgam as compared with other materials, access to dental care, and waste management and cremation practices. Emissions from dental amalgam can result from preparation and removal of dental amalgam, disposal, waste, cremation, and so on. While it is estimated that mercury emission to air from cremation accounts for ~0.25% of the total, emissions from the other processes associated with use from dental amalgam have not been quantified (UN Environment 2019). While the treaty requires the phase-out of many mercuryadded products (with exceptions for products used for military use, research, religious practices, vaccines, and for which there is no suitable alternative), the parties agreed to a phase-down of dental amalgam (annex A, part II; Minamata Convention on Mercury 2017), since there was not at the time—and there is not currently—a replacement material that is as inexpensive, easy to handle, and, most important, durable as dental amalgam. The treaty development process, negotiations, and role of the dental research community were reviewed by Meyer et al. (2016). The IADR is committed to 1) placing increased emphasis on research into primary prevention and behavior change strategies that will reduce the prevalence of dental caries and 2) promoting research into new dental materials that could one day replace dental amalgam entirely. In November 2019, the parties considered a proposal to phase out dental amalgam by 2024 except where no alternative is available. The IADR worked with the FDI World Dental Congress, American Dental Association, and International Dental Manufacturers and conducted meetings with US delegates to the conference from the US State Department and Environmental Protection Agency (EPA). The IADR (2019) also submitted a research report to the treaty secretariat showing that although research on alternative restorative materials was advancing, new materials were still not completely developed and would not be optimal replacements for dental amalgam in all situations for clinical, economic, or practical reasons. Since the adoption of these statements, the US Food and Drug Administration (FDA; 2019) published an updated systematic literature review, which concluded,