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 tattoo of discolored mucosa is much larger. If necessary, the diagnosis can be confirmed histologically by excisional biopsy, which excludes nevi and melanomas. If a biopsy is taken, the histopathologic appearance is: Theoretically, routine use of a dental dam during dental procedures which involve amalgam should reduce the risk of amalgam tattoo. No treatment is required since the lesion is entirely benign. Some suggest that amalgam tattoos are best surgically excised so as to ensure the lesion does not represent a melanoma. Other say that excision should only be carried out if there is any doubt over the diagnosis, and that