Dental amalgam controversy of mercury received by sewage treatment plants. The mercury contaminates the treatment plant sludge, which is typically disposed of by land application, landfilling or incineration. Several states, including New Jersey, New York, and Michigan, have required the installation of dental amalgam separators prior to 2017. EPA promulgated an effluent guidelines regulation in 2017 which prohibits most dental practices from disposing amalgam waste down the drain. Most dental offices nationwide are now required to use amalgam separators. The WHO reported in 2005 that in the United Kingdom mercury from amalgam accounted for 5% of total mercury emissions. In Canada, dental amalgam
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