Are Dental Implants Safe for MRI?

When looking for dental implantology, it is important to consider the safety of Magnetic Resonance Imaging (MRI). Fortunately, MRIs are completely safe to perform on patients with dental implants. Dental implants and magnetic resonance technologies continue to advance, which is good news for patients who can benefit from both. Because most implants are safe for MRI, you don't have to worry that the dental treatment you're receiving now will limit your medical imaging options in the future.

There's no reason to be concerned about MRIs when you have dental implants. Magnetic resonance imaging (MRI) is widely used for the diagnosis, staging, and monitoring of diseases. It has excellent soft tissue contrast and is considered safer than other modalities, as it does not expose the body to radiation. However, magnetic resonance imaging is not without risks.

The presence of a metal implant in the patient's body during an MRI can be dangerous due to excessive magnetic field interactions. Advances in medicine have led to the use of several implants, such as dental and orthopedic implants, in our body. In the field of craniofacial surgery, titanium plates and screws are frequently used for cranioplasty, facial bone reconstruction and orbital bone reconstruction, as they offer excellent results without posing major problems in terms of biosafety. But some doctors have wondered if titanium implants are actually safe for magnetic resonance exams.

The greater the number of elderly patients, the greater the chance of having a brain MRI due to cerebrovascular disease. This has led to questions about whether the widespread use of titanium implants in the craniofacial region is acceptable, given the likelihood that patients will undergo a brain MRI in the future. In this article, we present the mechanism of magnetic resonance and its relationship to metals, especially titanium, and review the concerns that have been raised about titanium materials in magnetic resonance imaging. During an MRI, a person is placed in a cylindrical machine and a wire is wrapped around the cylinder.

When electricity passes through this cable, a magnetic field flows through the cylinder. In magnetic resonance imaging, a magnetic field is applied to our body and the imaging device detects the signal produced in response to the magnetic field and takes pictures of it. Common sense indicates that we should not bring metal close to an MRI machine. Although the term “magnetism” is often used to refer to the magnetic properties of metals, all materials have magnetism which can be classified as ferromagnetism, diamagnetism and paramagnetism.

Ferromagnetic substances are materials that are magnetized even when there is no external magnetic field. When a ferromagnetic substance approaches an MRI machine, it attaches to the machine due to its strong magnetic field or moves to another location. Representative ferromagnetic materials include iron, cobalt and nickel. Diamagnetic substances are magnetized in the opposite direction to the magnetic field when placed in a magnetic field, although diamagnetism disappears when the magnetic field disappears.

Representative materials include copper, glass and plastic. Paramagnetic substances are weakly magnetized by an external magnetic field and lose their magnetism when the external magnetic field is eliminated. Most substances belong to this category including titanium. The Food and Drug Administration receives approximately 300 annual reports of adverse events in magnetic resonance imaging. Contact burns due to skin-to-skin contact or to external metal objects such as electrocardiogram cables, pulse oximeters and medical patches are more commonly reported.

The following most commonly reported events include damage caused by projectiles, accidents involving objects moving due to the magnetic field, finger injuries caused by the patient's table, patient falls, hearing loss and tinnitus - all of which are not related to the presence of surgical implants. Because MRI devices use strong magnets, metal implants present a specific risk of potential implant migration and radiofrequency (RF) -induced implant heating which can damage surrounding tissue. Metal implants can cause artifacts in the image that lead to a misinterpretation of results. Advances in technology can minimize image distortion by modifying magnetic resonance pulse sequences and optimizing scanning parameters. When deciding whether patients should undergo an MRI doctors must consider both advantages of imaging and possibility of image distortion due to implants. Titanium is a paramagnetic material that is not affected by the magnetic field of magnetic resonance imaging.

The risk of implant-related complications is very low and magnetic resonance imaging can be used safely in patients with implants. However titanium plates used in craniofacial area are made of alloys so more precise research is needed because effects of magnetic resonance depend on ratio of components of alloy. The variety of implant options allows patients to have a full set of teeth instead of dentures or bridges.