Nuclear magnetic resonance (NMR) is the use of atomic nuclei resonating in a magnetic field to generate signals for computerized imaging, and amalgam is an antimagnetic material that basically does not affect NMR imaging. Most of the components of amalgam are mercury, and a small amount of silver, tin and other small amounts of metal, and mercury belongs to the antimagnetic material, when doing MRI, the components of amalgam basically will not have too much effect on the magnetic field. However, in the case of other alloy materials in the oral cavity such as nickel-chromium alloy, it is not possible to do an MRI. In addition to silver amalgam, fillings made of gold, titanium, resin and other materials are anti-magnetic and can also do MRI. To be on the safe side, you should explain the situation to your doctor before doing the checkup and let him or her make a specific judgment.