Is dental amalgam safe when it rests against another metal (e.g. braces) in the mouth?
It should be noted that Health Canada has taken the position that “new amalgam fillings should not be placed in contact with existing metal devices in the mouth, such as braces.” Health Canada’s concern is related to galvanic effect, which occurs when two different metals are in close proximity and create the potential for electric current to be generated. Dentists are aware of the possibility of abutting metals creating a galvanic effect. It is also recognized that galvanic effect, through corrosion of metallic dental materials, may increase the release of mercury and other elements or compounds. Some recent evidence suggests that galvanic effect may also slightly increase the release of mercury vapour from amalgam. For all these reasons, it is prudent for dentists, in suggesting a restorative material, to avoid creating a galvanic effect whenever patient care will not be compromised. It is also inadvisable to remove existing fillings unless the patient complains of symptoms which may
