Sir, Fisher et al. have briefly commented on mercury-free materials for dental restoration.1 Dental amalgam, an alloy of mercury and silver, has been in use for over 150 years for the treatment of dental cavities, due to its excellent mechanical properties and durability.2
Dental amalgam toxicity has been investigated by reliable research institutes including US FDA (Food and Drug Administration),3 European Commission,4 and the American Dental Association.5 They have concluded that dental amalgam is regarded as safe.3,4,5
However, in the Minamata Convention, dental amalgam is the only mercury-added material subject to a phase-down.1,6,7 All other mercury-added materials addressed in the Convention are subject to a ban or phase-out. The conclusion is based on aiding mercury pollution policy.
However, according to the data by United Nations Environment Programme (UNEP) which has initiated the dental amalgam policy,8 a large part of produced mercury has been used in small scale artisanal gold mining which has been seriously causing mercury pollution - 1,735 tons per year.8
The global mercury supply in 2015 was in the range of 3,850-4,400 tonnes.8 Therefore, the mercury pollution has been largely from gold mining. Natural emissions, such as those from volcanic activity or forest fires, are estimated to be at around 87 tonnes per year in 2010.2
Releases into the air from dental practices are estimated to be at around 19 tonnes per year.2 In other words, WHO and UNEP have made the illogical conclusion on dental amalgam policy.
Fisher J, Selikowitz H S, Mathur M, Varenne B. Strengthening oral health for universal health coverage. Lancet 2018; 392: 899-901.
European Commission. Mercury from dental amalgam. Available at https://ec.europa.eu/health/scientific_committees/docs/citizens_dental_amalgam2_en.pdf (accessed February 2018).
USA FDA. About Dental Amalgam Fillings. Available at https://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/DentalProducts/DentalAmalgam/ucm171094.htm (accessed february 2018).
European Commission. Final Opinion on Dental Amalgam. Available at https://ec.europa.eu/health/scientific_committees/consultations/public_consultations/scenihr_consultation_24_en (accessed February 2019).
American Dental Association. Dental Amalgam: What Others Say. 2016. Available at https://www.ada.org/en/press-room/press-kits/dental-fillings-press-kit/dental-amalgam-what-others-say (accessed February 2019)
FDI World Dental Federation. Dental amalgam: The Minamata Convention on Mercury. Available at https://www.fdiworlddental.org/what-we-do/advocacy/dental-amalgam (accessed February 2019).
World Health Organisation. The Minamata Convention and the phase down of dental amalgam. 2018. Available at http://www.who.int/bulletin/volumes/96/6/17-203141/en/ (accessed February 2019).
United Nations Environment Programme. Global mercury supply, trade and demand. 2017. Available at https://wedocs.unep.org/bitstream/handle/20.500.11822/21725/global_mercury.pdf?sequence=1& (accessed February 2019).
About this article
British Dental Journal (2019)