Dental amalgam controversy demonstrated that mercury released from amalgam restorations does not give rise to toxic effects on the nervous system of children. More recently, a Cochrane Systematic review in 2014 found, "insufficient evidence to support or refute any adverse effects associated with amalgam or composite restorations." Those opposed to dental amalgam suggest that mercury from dental amalgam may lead to nephrotoxicity, neurobehavioural changes, autoimmunity, oxidative stress, autism, skin and mucosa alterations, non-specific symptoms and complaints, Alzheimer's disease, and multiple sclerosis. Both those opposed and those not opposed to dental amalgam recognize that amalgam has been found to be a rare contributor to
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