Amalgam (dentistry) and other metals may be present in some alloys. This combination of solid particles is known as amalgam alloy. The composition of the alloy particles are controlled by the ISO Standard (ISO 1559) for dental amalgam alloy in order to control properties of set amalgam such as corrosion and setting expansion. It is important to differentiate between dental amalgam and the amalgam alloy that is commercially produced and marketed as small filings, spheroid particles, or a combination of these, suitable for mixing with liquid mercury to produce the dental amalgam. Amalgam is used most commonly for direct, permanent, posterior restorations
Dental amalgam controversy ADA asserts the best scientific evidence supports the safety of dental amalgam. Clinical studies have not established an occasional connection between dental amalgam and adverse health effects in the general population. In 2002, Dr. Maths Berlin of The Dental Material Commission published an overview and assessment of the scientific literature published between November 1997 – 2002 for the Swedish Government on amalgam and its possible environmental and health risks. A final report was submitted to the Swedish Government in 2003 and included his report as an annex to the full report. In the final report from 2003, Berlin states that