Metal prostheses are now used to replace missing of faulty parts of the human body quite often. They range from dental implants to full-sized prosthetic limbs. Metal plates and screws have long been used to support and join fractured bones in the body.
Since dental implants are made from metal, one of the anxieties that patients have while considering a dental implant is whether the implants will, in any way, affect their daily life or ability to get other medical procedures.
What is an MRI?
Unlike X-rays and CT scans that use radiation to take a picture of the bones, an MRI is basically a very strong magnet. An MRI is a huge cylindrical machine. A patient is asked to lie still inside the machine, which then produces very strong magnetic and radio waves, forming an image of the tissues inside the body.
The magnetic force generated by an MRI machine is so strong that it has been known to attract metallic objects of any size — from a small nail to wheelchairs and oxygen cylinders present in the room — when the machine is switched on.
Large-sized metal prostheses, or old tattoos containing metals in their ink, pose a serious problem while taking an MRI. Certain metals are also known to considerably heat up due to an interaction with the magnetic waves and cause severe discomfort.
MRI and dentistry
Several dental prostheses, like cast partial dentures, orthodontic braces, and dental crowns, contain alloys made up of nickel, cobalt, and steel. Before entering an MRI room, the patient should take out all removable prostheses to avoid any interaction with the MRI.
Orthodontic braces made up of stainless steel alloys should ideally be removed prior to an MRI to avoid accidents.
Braces made of titanium or ceramic may, however, be left on during the scan although they may cause some amount of distortion in the image.
Are dental implants safe during an MRI?
Dental implants are typically made from metal. Since magnets attract metals, patients are generally concerned about how a piece of metal in their jaw will react during an MRI.
Metals that are very weakly attracted to a magnet are known as paramagnetic. Titanium or titanium alloys, the material from which most dental implants are made, belong to this category. Hence, dental implants will not usually be attracted by the MRI machine. They will not be pulled out from your jaw.
Recently, certain dental implants have been fabricated from zirconium, as well. The prosthetic crown or bridge given over the implants, especially if they are PFM prosthesis, may contain alloys made of ferromagnetic metals. Hence, it is important to mention any implant treatment that you may have undergone previously to your radiologist.
Can dental implants interfere with MRI image quality?
Before getting an MRI, especially for diagnosing any anomalies in the head and neck region, it is important for you to inform the radiologist if you have a dental implant or any other metal prosthesis or fillings in your mouth. This is because metal prosthesis and fillings can interfere with the quality of the MRI image.
The images around the areas having implants may show artifacts or distorted images due to the deflection of magnetic fields around the implants. These artifacts may interfere with the diagnosis of lesions.
Dental implants and airports
The embarrassment and the inconvenience of being singled out by airport security during security checks is something that no one wants to ever go through. Imagine being a frequent flier and having to explain why the scanners are going off every time you go through them! Not a pleasant thought at all.
With many international and domestic airports now employing full-body scanners, your dental implant can pop up in the imaging software at such terminals.
However, the relatively small size and the location of the dental implants make them quite easy to recognize. Most airport security agents are well trained to identify dental implants, so it should be of no concern to them.
Conclusion
Newer prostheses are made from materials that are inert and cause minimum disruption in patients' daily activities. With the widespread use and awareness of dental implants, the majority of physicians and radiologists are used to scanning patients with dental implants.
Airport security staff too are educated and trained in such a way that they can readily identify dental implants and cause minimum disruptions during your security checks.