Dental amalgam is typically comprised of 50% mercury, 35% silver, 15% tin & other metals. There is considerable controversy over whether dental amalgam is harmful to health, with organisations such as the American and British Dental Associations claiming it to be harmless.

A report published by the World Health Organisation in 1991 claimed that dental amalgam is the main source of mercury exposure in humans. The range of ailments that have been linked (directly or indirectly) to low-level mercury poisoning include ME/CFS (Chronic Fatigue Syndrome), Alzheimer‟s Disease, Multiple Sclerosis, and a whole range of autoimmune illnesses. Some countries, like Sweden, Canada and Germany, have either banned or imposed serious limitations on amalgam usage.

A large scale study (20,000 participants) in Sweden found that there are significant increases after chewing in the levels of mercury in the saliva of patients with amalgam fillings. These levels were estimated to be higher than the WHO upper tolerable limit in a least 30% of subjects.

• Brain and serum levels of mercury increase proportionally with the number of amalgam fillings
• Bruxism (tooth grinding) vaporises fillings and increases exposure
• Chewing gum increases exposure
• Removal too rapidly, or with no more than „standard techniques,‟ or can lead to increased exposure