Many countries have banned the use of mercury amalgam fillings. The WHO have called for a ban in all countries by 2020. The EU want a ban in all European countries by 2018. Over 300 research studies have conclusively proved that mercury amalgam is causing a multitude of serious diseases. Conversely no research has ever established the safety of the amalgam. Nor will research ever establish the safety of mercury amalgam because it cannot prove that it is NOT causing sub-clinical disease.
The main problem is that the elemental mercury leaks out and accumulates in the body. In some parts of the brain it has a half-life of nearly 30 years. In the heart it can reach levels thousands of times more than the natural level causing heart attacks. About 10 to 15% of patients become hypersensitive to the mercury and a battery is created in the oral cavity which can interfere with nervous transmissions.