Let’s first look at the basic principle of MRI. The human body contains a very rich amount of water, and the amount of water varies from tissue to tissue. If we can detect information about the distribution of this water, we can draw a more complete picture of the internal structure of the human body. The basic principle of MRI is to place the human body in a special magnetic field and use radio frequency pulses to excite the hydrogen nuclei in the water molecules in the human body, causing the hydrogen nuclei to resonate and absorb energy. After stopping the radio frequency pulse, the hydrogen nuclei emit radio signals at specific frequencies and release the absorbed energy, which is collected by the receiver outside the body and processed by an electronic computer to obtain images, which is called MRI. Since there is a very strong magnetic field in the MRI machine and the MRI examination room, it is absolutely forbidden to do MRI examination for those who are equipped with pacemakers, those who have metal clips or metal stents after vascular surgery, or those who have metal stents for coronary artery, esophagus, prostate, or bile duct surgery, otherwise, the metal will be attracted by the strong magnetic field and move, which may have serious consequences. The material used for dental implants is pure titanium, which is the most biocompatible metal known, and it is a non-magnetic metal that will not be magnetized in a large magnetic field, so the implant itself has no effect on the MRI. The implant is a non-magnetic metal and will not be magnetized. All-porcelain materials are non-metallic and have no effect on MRI, while metal porcelain teeth have varying degrees of interference with MRI imaging due to different types of metals. The porcelain metal commonly used for denture restoration are gold alloy, pure titanium, nickel-chromium alloy, cobalt-chromium alloy, etc. Previously discussed pure titanium class (not titanium alloy yo) no effect. And a lot of experimental data show that gold alloy class precious metal in the magnetic resonance examination only slight artifact interference, while nickel-chromium alloy and cobalt-chromium alloy and other non-precious metals will produce larger artifacts, have a certain impact on the magnetic resonance examination. Is it true that non-precious metal restorations in the oral cavity must be removed first when doing MRI? Actually, it is not necessary. These dental alloys do not cause any harm to the body during MRI, but only interfere with the imaging in a certain area around the restoration. If the area to be examined is not near the metal restoration, it will not interfere with the diagnosis of the disease and there will be no need to remove the restoration. We can properly choose the material of the denture restoration according to our own situation: generally the preferred materials are all-ceramic, pure titanium and precious metals, because these materials are aesthetically pleasing and hardly bring adverse reactions such as allergies to the human body, and do not interfere with the diagnosis when doing MRI examinations, but the cost is relatively high. Of course, if you choose common metals, it is not necessary to remove them all before the MRI.