From a medical site...what do you think?
From the MRI Research Center:
Eligibility criteria for participants
Before each MRI/MRS session there will be a series of screening and safety questions to determine if you are eligible for participation. In general, eligible participants must be able to answer NO to the following questions:
A. Do you have a cardiac pacemaker, neurostimulator or hearing aid?
The high magnetic field interferes with the proper functioning of implanted devices, like cardiac pacemakers.
B. Do you have any metal in or on your body?
This includes pins, screws, plates, scrapnel, clips and dental braces, but also jewelry and body piercing. Magnetic metals may get bent or moved out of place, while non-magnetic metals will tend to heat up.
C. Are you claustrophobic?
The MRI/MRS magnet is a long but very narrow (three feet) tube. When inside the magnet, the outside is not directly visible thereby emphasizing the impression of a narrow enclosed space. The coil, which resembles a helmet, is even smaller and may enclose your head with less than a few centimeters to spare. The cushions and head band used to minimize head motion will further reduce the available space.
While you will be able to get out of the magnet at any time during the experiment, you should be aware that it is an extremely confined space in which you will need to lie absolutely still for a minimum of one hour for a successful completion of the session.
What about tooth fillings?