Will an MRI Affect Dental Fillings?

Will an MRI affect dental fillings?

Will an MRI affect dental fillings?

Check out this answer from Consensus:

The current body of research presents mixed findings on whether MRI affects dental fillings, particularly those containing mercury. While some studies indicate a potential for increased mercury release, others do not find significant effects. Given the potential health risks, it is essential for healthcare providers to be aware of these findings and consider them when planning MRI procedures for patients with dental amalgam fillings. Further research is needed to clarify the extent of these effects and to develop guidelines for safe MRI practices in patients with dental fillings.


Magnetic Resonance Imaging (MRI) is a widely used diagnostic tool in medicine due to its ability to produce detailed images of the body’s internal structures without the use of ionizing radiation. However, concerns have been raised about the potential effects of MRI on dental fillings, particularly those containing metals such as mercury. This article explores the current research on whether MRI can affect dental fillings and the implications for patient safety.

Dental amalgam fillings, which contain mercury, have been a subject of controversy due to potential health risks associated with mercury exposure. With the increasing use of MRI in medical diagnostics, it is crucial to understand whether the strong magnetic fields used in MRI can cause mercury release from these fillings, thereby posing a health risk to patients.

Mercury Release from Dental Amalgam Fillings

Several studies have investigated the potential for MRI to cause mercury release from dental amalgam fillings. One study examined the effect of high-field MRI (1.5 T) on mercury release in a controlled setting. The study found that urinary mercury levels in individuals exposed to MRI increased significantly compared to a control group, suggesting that MRI can indeed cause mercury release from dental amalgam fillings1.

Another study explored mercury release from dental amalgam fillings exposed to both 1.5-T and 7.0-T MRI in an ex vivo setting. The researchers found that mercury release occurred in both scenarios, with higher magnetic fields potentially leading to greater mercury release2. This study highlights the need for further research to understand the implications of different MRI field strengths on mercury release.

Safety Considerations

The safety of MRI, particularly at higher field strengths such as 7-T, has been a topic of concern. Higher magnetic fields can cause more pronounced bioeffects, including vertigo, dizziness, and other sensory disturbances3. These effects, combined with the potential for increased mercury release, underscore the importance of careful patient management and safety protocols during MRI procedures.

Conflicting Evidence

Despite the findings mentioned above, some studies have reported no significant increase in mercury release due to MRI. For instance, an in vitro study found no evidence of elevated mercury dissolution from dental amalgam during exposure to a 1.5-T MRI4. This discrepancy in findings suggests that more research is needed to reach a definitive conclusion.

Artifact Formation and Diagnostic Accuracy

MRI can also cause artifacts in images due to the presence of metallic dental materials. These artifacts can impair diagnostic accuracy, particularly in regions close to the oral cavity. Techniques such as multi-acquisition variable-resonance image combination (MAVRIC) have been developed to reduce these artifacts and improve image quality5.


Will an MRI affect dental fillings?

Rebecca Dewey has answered Unlikely

An expert from The University of Nottingham in Neuroimaging, Neuroscience

It’s unlikely to – your fillings don’t contain magnetic materials and they don’t form a current loop, i.e. a circuit through which an electrical current can flow. You might experience a metallic taste in your mouth but that’s not the scan per se – it’s the magnetic field gradient (i.e. the magnetic field changing over time or you moving from one area of the field to another) acting on your saliva/taste buds. That taste will stop as soon as you stay still or leave the field.

What’s more interesting though is the effect of your fillings on the MRI scan. The metal won’t generate any signal as it contains no water, and it will also cause there to be no signal in the surrounding areas, so you will look like those teeth are missing! No harm done though and your teeth are far enough away from your brain that it won’t make your images any less useful!

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