Whether a person with dental implants can safely undergo a Magnetic Resonance Imaging (MRI) scan is a common concern. For the vast majority of patients with modern restorations, the answer is a qualified yes, as contemporary implants are considered safe for MRI procedures. The materials used in dentistry do not pose a risk of movement or physical harm within the magnetic field. Potential effects usually relate to the quality of the resulting images rather than patient safety.
Implant Materials and MRI Safety
The safety of a dental implant during an MRI scan is determined by the magnetic properties of its construction materials. Modern implants are predominantly made from commercially pure titanium or titanium alloys, which are classified as non-ferromagnetic. This means they are either not attracted to the powerful magnetic field of the MRI machine or exhibit minimal paramagnetic susceptibility.
The non-ferromagnetic nature of titanium prevents the primary safety risk associated with MRI—the “missile effect”—where a strongly magnetic object is pulled violently toward the scanner’s bore. Titanium’s minimal interaction ensures the implant remains securely integrated into the jawbone. Zirconia, an increasingly popular alternative, is a ceramic material that is entirely non-metallic and non-magnetic, offering complete compatibility. Both titanium and zirconia implants meet the standards for safe use under the magnetic field strengths of modern 1.5 Tesla (T) and 3.0T MRI scanners.
Risks of Image Distortion and Heating
Although dental implants are safe for the patient, their metallic presence can still affect the quality of MRI images, especially when the scan focuses on the head and neck region. This interference manifests as signal voids or bright spots known as metallic artifacts. These artifacts are caused by the localized disruption of the magnetic field homogeneity surrounding the implant, which degrades the image quality in that small area.
Titanium implants produce more pronounced artifacts than zirconia, due to titanium’s weakly paramagnetic nature. Studies using 3.0T scanners measured the distribution of titanium artifacts to be approximately \(2.57 pm 1.09\) millimeters, compared to \(0.37 pm 0.20\) millimeters for zirconia artifacts. These distortions may obscure adjacent anatomical structures, making diagnosis difficult if the area of interest is next to the implant. Radiologists can employ specialized imaging sequences and artifact reduction techniques to mitigate this effect.
Another concern is the potential for radiofrequency (RF) energy absorption to cause heating of the implant and surrounding tissue. The RF pulses used to generate the images can induce electrical currents in conductive materials like titanium. Research in tissue-equivalent phantoms at both 1.5T and 3.0T field strengths measured a maximum temperature rise of only \(0.4^{circ}\)C. This minimal increase is far below the \(2^{circ}\)C threshold considered a risk for tissue damage, confirming that the thermal risk posed by titanium dental implants is negligible.
Patient Communication and Preparation
Because safety and image quality can be affected by the implant’s specific composition, open communication with the healthcare team is necessary before undergoing an MRI. Patients should inform the referring physician, the MRI technologist, and the radiologist about the presence, location, and type of all dental restorations. This information allows the imaging center to confirm the implant’s compatibility status and adjust scan parameters to minimize image artifacts.
Patients should consult their dentist to obtain available documentation regarding the implant, such as a manufacturer’s card or record of the materials used. Knowing the specific brand, material (e.g., titanium alloy, zirconia), and placement date expedites the safety screening process. Any removable metallic prosthetics, such as partial dentures with metal clasps or magnetic attachments, must be taken out before entering the MRI suite.