Marshall, in his review on dental amalgam, summed it up appropriately: “if some reported values of Hg release are extrapolated to clinical life times, the entire restoration could lose its Hg in short time. For example, a 500 mg amalgam restoration contains approximately 200–250 mg of Hg, and the entire quantity of Hg would be lost in 10,000 days if the Hg was released at the rate of 25 μg/day. This estimate of release is of the order of magnitude reported in some studies of vapour release