Amalgam (dentistry) disposal. Dental amalgam is the largest source of mercury received by U.S. treatment plants. The U.S. Environmental Protection Agency (EPA) promulgated an effluent guidelines regulation in 2017 which prohibits most dental practices from disposing dental amalgam waste down the drain. Most dental offices in the U.S. are required to use an amalgam separator in their drain system. The separator captures the waste material, which is then recycled. The European Commission has issued a Waste Directive that classifies amalgam waste as a hazardous waste. The waste should be separated from other waste by fitting amalgam separators in all dental practices. Mercury
Amalgam (dentistry) problem. This phase has been shown to be the weakest phase in the set amalgam and is subject to corrosion, particularly at the tooth-amalgam interface. In 1962 a new amalgam alloy, called Dispersalloy, was introduced with the addition of a spherical silver-copper eutectic particle to the traditional lathe-cut AgSn particle in a ratio of 1:2. The mixture of these two types of particles is known as admix alloy. The benefits of this alloy was to strengthen the set amalgam and reduce the γ phase (SnHg). The increased copper in the silver-copper eutectic reacted preferentially with tin so that SnHg could