High-strength MRI may release mercury, a known toxin, from amalgam fillings in teeth, according to a new study published in Radiology.
Amalgam fillings, commonly known as silver fillings, remain common in the United States, though their use has been banned or limited in countries such as Sweden and Germany. These fillings contain mercury, which can cause harm to humans.
The authors placed 20 randomly selected teeth with amalgam fillings in a solution of artificial saliva and exposed them to 1.5-T or 7-T MRI. A control group of teeth was placed in artificial saliva, but not exposed to MR imaging.
Overall, the team found that the mercury content in the 7-T group was much higher than levels found in the 1.5-T group of teeth and the control group.
“In our study, we found very high values of mercury after ultra-high-field MRI,” lead author Selmi Yilmaz, PhD, a dentist and faculty member at Akdeniz University in Antalya, Turkey, said in a prepared statement. “This is possibly caused by phase change in amalgam material or by formation of microcircuits, which leads to electrochemical corrosion, induced by the magnetic field.”
Yilmaz added that “it is not clear how much of this released mercury is absorbed in the body” and indicated further studies may be necessary.
Michael has more than 16 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.