Cancer myth: Dental fillings and cancer

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Origin of the myth

Many metallic fillings are made of amalgam – a mixture of mercury with silver, tin, and copper.  Some people have warned against the use of these amalgam fillings, in particular proponents of “biological dentistry”.

Biological dentistry is the removal of teeth or fillings which are said to contain toxins.  Practitioners of biological dentistry claim that the mercury in metal fillings can escape, travel to organs, and cause diseases, including cancer.

Current evidence

The World Dental Federation (FDI) released a statement confirming that small amounts of mercury are leaked from dental fillings.  These amounts are measured in nanograms (ng), which are one billionth of a gram.  The FDI and World Health Organization (WHO) assert that there is no evidence of a link between amalgam fillings and chronic degenerative diseases, autoimmune diseases, kidney diseases, altered cognitive function or adverse pregnancy outcomes.1, 2

The Australian Dental Association (ADA) states that the use of amalgam dental fillings produces no harmful effects.  They advise that it is not necessary to replace amalgam fillings, and warn that doing so can damage or weaken teeth and produce short-term sensitivity and pain in the mouth.3

The European Commission’s Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) has also declared dental amalgam safe to use.4 The American Dental Association has declared that unnecessary removal of fillings is unethical.5

A division of the World Health Organization, called the International Agency for the Research of Cancer (IARC) examined the toxicity in a report on surgical implants and foreign bodies.  Fillings were reviewed and were not classified as either carcinogenic or possibly carcinogenic.  The review also stated that there was insufficient evidence that  metallic implants were carcinogenic.6

The US Report on Carcinogens (RoC) is a list of known or reasonably anticipated human carcinogens (cancer causing substances).  Mercury is not on this list.7


To date, there is no evidence that amalgam fillings cause cancer, or have any other adverse health effects.  The only possible risk is that amalgam dental fillings can sometimes cause local side effects or allergic reactions.  These hypersensitivity reactions are rare and can be treated by removing the amalgam filling.

There are alternatives to amalgam fillings which can be used if you are still concerned about the carcinogenicity of mercury.  However, it is not advised that you remove your current amalgam filling to replace it with another filling.


1. FDI World Dental Federation, WHO Consensus Statement on Dental Amalgam, in FDI Policy Statement, FDI World Dental Federation, Editor. 1997, FDI World Dental Federation,: Dubai.
2. FDI World Dental Federation, Safety of Dental Amalgam, in FDI Policy Statement, FDI World Dental Federation, Editor. 2007, FDI World Dental Federation,: Dubai.
3. Australian Dental Association (ADA). Policy Statement 6.18 - Safety of Dental Amalgam. [Accessed 6 June 2019].
4. Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) Scientific Opinion on the Safety of Dental Amalgam and Alternative Dental Restoration Materials for Patients and Users, 6 May 2008. 
5. American Dental Association (ADA). ADA Statement on Dental Amalgam. ADA Positions and Statements  2007  [cited 7/08/2014]; Available from:
6. International Agency for Research on Cancer (IARC), Volume 74: Surgical Implants and Other Foreign Bodies, in IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, IARC, Editor. 1999, IARC: Lyon, France.
7. U.S. Department of Health and Human Services, 12th Report on Carcinogens. 2011, Public Health Service - National Toxicology Program.

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