The high-powered MRI machines that are making their way to modern hospital may cause mercury poisoning among patients who have dental fillings, according to a new study.

Mercury is a component of amalgam, which is a substance used by dentists to plug holes in teeth. With the results of the study, does it mean that people who have had dental fillings with amalgam should seek a replacement?

MRI Machines May Cause Mercury Poisoning

Scientists discovered that 20 minutes of exposure to high-strength MRI may release the mercury in amalgam used for dental fillings. The findings, which were published in the Radiology journal, present a huge risk because metal fillings are still one of the most common types of dental filling offered by dentists.

Metal dental fillings use amalgam, which is composed of 50 percent mercury and the rest made up of a mix of other metals. While mercury is a highly toxic heavy metal, it is considered safe as part of dental amalgam. The mercury is sealed inside a protective film layer covering the filling's surface, with complete hardening achieved after 48 hours from setting the fillings.

However, the strong magnets in new MRI machines are capable of breaking down the metal fillings. The study showed that unsafe mercury levels were found in saliva after a tooth with dental fillings underwent a high-powered MRI. The magnets were apparently corroding the amalgam, which allows the mercury to leak.

The threat of mercury poisoning is a serious one, as it may cause extensive damage to a person's digestive, nervous, and immune systems. High levels of mercury in a person's blood may lead to brain damage, a higher chance of heart disease or heart attack, increased risk of women having babies with deformities, and lower sperm counts for men.

Should People With Metal Fillings Worry?

Mercury poisoning is not one of the previously listed risks of MRI scans, but it is now a problem with the advancement of MRI technology. With the healthcare industry continuing to move forward, should people with metal fillings consult their doctor on the possibility of having the amalgam in their teeth replaced?

For now, there is no cause for concern. The study utilized a 7-T machine, which is over four times more powerful than regular MRI machines found in hospitals and are currently used for research.

According to the study, there is no definite evidence yet that people should have metal filling removed as a precaution on the chance that they will undergo a high-powered MRI. More studies will be needed to provide a better assessment, as MRI technology continues its improvement.