Dental amalgam controversy respondents would prefer to be told about mercury in dental amalgam before receiving it as a filling. A 1993 study published in FDA Consumer found that 50% of Americans believed fillings containing mercury caused health problems. Some dentists (including a member of the FDA's Dental Products Panel) suggest that there is an obligation to inform patients that amalgam contains mercury. A prominent debate occurred in the late 20th century, with consumer and regulatory pressure to eliminate amalgam, "at an all-time high". In a 2006 nationwide poll, 76% of Americans were unaware that mercury is the primary component in amalgam fillings,
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