Amalgam
Dental amalgam is a silver-coloured filling material. It is made of mercury, silver, copper, zinc and tin. It has been used as a filling material to fix teeth for over 150 years and has one of the longest life-expectancies of dental filling materials. Dentists and scientists have done a lot of research on dental amalgam.
Amalgam was commonly used by dentists in the 1990’s. These days it is used less commonly. Some dental practices do not use it at all any more. Amalgam is strong and long-lasting, but more tooth structure needs to be cut away to fix the tooth with an amalgam filling. This is because the amalgam is held in place by the shape of the cavity that is cut into the tooth. Amalgam does not stick to the tooth surface like white filling materials do.
This filling material is silver in colour and can appear darker over time. Some people claim that mercury in dental amalgam can cause health issues. There is no quality research that has shown that this is true. Scientific research has shown that the mercury in amalgam fillings is not absorbed well by the body. Small amounts of mercury from amalgam do get into the blood but are removed by the kidneys and passed out of the body in urine. There are only two proven side-effects of amalgam:
- Lichen planus - a condition involving small sores on the gum or inside of the cheek.
- An allergic reaction affecting the soft tissues near the filling. Signs of an allergic reaction can include swelling, redness, and itching, but these are rare.
Dental amalgam has been used less and less in dental clinics over the years. The decreased use of amalgam is not due to concerns directly related to human health but concerns about the environment. Mercury from dental clinics can get into the environment. To stop this, dentists have created policies and installed equipment to help them to safely get rid of amalgam waste to limit the amount released into the environment.

A dental amalgam filling in a molar tooth. Getty Images.