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 safety and effectiveness of amalgam restorations. In 2012, the Australian Dental Association published a position paper on the safety of dental amalgam. Their position is that "Dental Amalgam has been used as a dental restorative material for more than 150 years. It has proved to be a durable, safe and effective material which has been the subject of extensive research over this time" and that "amalgam should continue to be available as a dental restorative material". Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) is a scientific committee within the European Commission. In a 2008 document of 74