Dear Mr Clarke,
Thank you for your email of 1 November to the Department of Health about dental amalgams. I have been asked to reply.
Dental amalgam has been in use for over 150 years with fillings placed in billions of people. Only a very few adverse reactions have been noted in the very small number people who are allergic to mercury. There have been successive expert reports corroborating the empirical evidence on safety. Mercury exposure from fillings is thought to be about the same as that from the diet, and therefore does not pose a significant health risk.
In 1997, the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment’s (COT’s) statement on the toxicity of dental amalgam concluded that the use of dental amalgam is free from risk of systemic toxicity and that only a very few cases of adverse reactions occur, despite its widespread use over the past 150 years.
Other studies that confirm the Department’s policy of the use of dental amalgam include a 1997 assessment by the World Health Organization (WHO) that concurred with COT’s review, and stated that ‘dental amalgam restorations are considered safe, but components of amalgam and other dental restorative materials may, in rare instances, cause local side-effects or allergic reactions. The small amount of mercury released from amalgam restorations, especially during placement and removal, has not been shown to cause any other adverse health effects.’
In 1998, a report by an expert group working on behalf of the European Commission (EC) concluded that, based on the available data, mercury from dental amalgam restorations does not cause an unacceptable health risk to the general population. All dental restorative materials, including dental amalgam and its alternatives, have the potential for causing some adverse reactions, and most contain components that might be toxic, but only at much higher doses than are released from dental use.
In February 2002, the United States Food and Drug Administration reported evidence that came to similar conclusions to the EC, namely that no valid scientific evidence has ever shown that amalgam causes harm to patients with dental restorations, except in the rare case of allergy.
More recently, the WHO report ‘Future Use of Materials for Dental Restorations’ November 2009 concluded that dental amalgam remains a dental restorative material of choice in the absence of an ideal alternative. WHO concurs that the available evidence suggests that dental amalgam is a safe and effective filling material and notes that alternative filling materials are not without clinical limitations and toxicological hazards. The Department concurs with the conclusions of the report.
The general view amongst experts remains that dental amalgam is the most convenient and durable material for filling cavities in back teeth. ‘White’ fillings are available for restoring front teeth but the use of white fillings on back teeth is more for cosmetic reasons than clinical effectiveness. However, dentists can use white fillings on back teeth providing this is clinically necessary, for example if a patient is allergic to mercury. The EC Scientific Committee report also concluded that alternative filling materials are not without risk.
As a precautionary measure the Department advises dentists to avoid the placement or removal of amalgam fillings during pregnancy unless clinically necessary, although there is no evidence of any harm to unborn children from the use of amalgam.
In conclusion, amalgam will continue to be used in the NHS, but in decreasing quantities as dental health continues to improve. The Department will continue to monitor research into its effects, the appropriateness of alternative materials and the best available international evidence.
I hope this reply is helpful.
Customer Service Centre
Department of Health