To date, extensive research has failed to establish any links between amalgam use and general ill health. Most dentists are continuing to use amalgam for cavities where a very durable material is needed - especially in the chewing surfaces of posterior teeth. In many respects amalgam is an ideal filling material. As well as being very durable, it expands and contracts with temperature change at the same rate as the surrounding natural tooth. Like most biomaterials, dental amalgam is not inert.
Amalgam fillings release mercury vapor, especially when teeth are chewed on or brushed.
Some of the vapor is exhaled but some reaches the rest of the body through inhalation. Part of it also dissolves in saliva and is swallowed. Much of the mercury entering the body is excreted but some accumulates in certain organs - especially the kidneys but also, to a very much lesser extent, in the brain, lungs, liver and gastrointestinal tract. However, experts do not believe that the levels of mercury exposure resulting from amalgam fillings are of any general health significance. The amount of mercury that reaches the rest of the body is very small.