How does magnetic resonance imaging affect fillings?
Many people are afraid to go to the dentist. In most of them, this fear is rather unfounded, however, some fillings used can pose an unexpected risk. When patients with such fillings in their teeth undergo magnetic resonance imaging, mercury can escape through their mouth.
In their current investigation, the scientists at Akdeniz University found that amalgam fillings in teeth can release mercury in the mouth after magnetic resonance imaging. The doctors published the results of their study in the English-language journal "Radiology".
Toxic metal is released in the mouth
It is certainly not a nice idea that they might have mercury in their mouth after visiting the dentist. Experts from Turkey found that a relatively new type of magnetic resonance imaging leaks mercury into your mouth. In other words, a simple medical exam could release a toxic metal in your mouth.
How strong is the magnetic field in magnetic resonance imaging?
Magnetic resonance imaging is a body scanning technique that has been around for almost 50 years. As the name suggests, this technique is based on the use of strong magnetic fields to generate images of internal organs, the authors of the study explain. A normal magnetic resonance tomography uses a magnetic field of 1.5 T (Tesla - the unit of measurement for the magnetic field strength). For comparison: the magnetic field that surrounds our entire planet is only about 0.00005T.
How do ultra-high magnetic fields affect dental implants?
A new type of MRI scanner has been in commercial production since the early 2000s. This can generate magnetic fields with a strength of 7 T and higher. According to the FDA (U.S. Food and Drug Administration), strengths of up to 8 T are not a significant health risk and the new devices have become increasingly popular. Nevertheless, concerns continued that too little research had been done on device safety. In particular, doctors asked themselves whether it is known how the ultra-high magnetic fields would affect surgical and dental implants in patients.
Research focused on 60 teeth filled with amalgam
In the current study, the experts researched 60 human teeth, which were extracted for various reasons. These teeth were given an amalgam filling - a type of silver that is mostly used for a normal filling. Then the teeth were assigned to three different groups. One group underwent normal 1.5T magnetic resonance imaging, the second group underwent 7T examination and a control group did not undergo such treatment. The teeth were then exposed to artificial saliva in the laboratory for nine days. Then the amount of mercury that had leaked out of the teeth by the treatment was measured.
How much mercury leaked out of the fillings?
The mean amount of mercury that emerged from a normal MRI scan was slightly higher than that from the control group. When treated with an ultra high magnetic field, almost five times as much mercury was released. The researchers also found that other dental implants also had problems, with gold and platinum crowns getting hotter under the higher magnetic fields. (as)