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 from pencil leads), and is sometimes termed a "graphite tattoo", although this is less common than tattooing with amalgam. The diagnosis is clinical. Amalgam tattoo can be distinguished from other causes of localized oral pigmentation because it does not change significantly in size or color, although it may appear to slowly enlarge for several months after the initial implantation of the metal particles. Some amalgam tattoos appear radio-opaque on radiographs (i.e. they show up on x-rays), although in many cases amalgam tattoos have no radiographic features since the responsible particle(s) of amalgam are very small even though clinically the area