Dental Crowns: Airport Security & MRI Scans Explained

Introduction

If you have recently had a dental crown fitted — or are considering one — you may have found yourself wondering whether it could cause complications during everyday situations like passing through airport security or undergoing a medical MRI scan. These are entirely reasonable questions, and you would not be alone in searching for clear, reassuring answers online.

Dental crowns are one of the most commonly used restorations in modern dentistry. They can be made from a variety of materials, including porcelain, ceramic, metal alloys, or a combination of these. Because some crowns contain metal components, patients naturally want to understand whether these materials could set off a metal detector at an airport or interfere with the powerful magnetic field used during an MRI scan.

This article provides a straightforward, educational explanation of how different dental crown materials behave in these situations, what you might reasonably expect, and when it would be appropriate to seek further clinical advice from your dental or medical team.

Featured Snippet: Can a Dental Crown Affect Airport Security or an MRI Scan?

Can you go through airport security or have an MRI scan with a dental crown?

In most cases, dental crowns do not trigger airport security scanners and are generally considered safe during MRI scans, though this depends on the crown material. Metal-containing crowns may occasionally be detected, whilst porcelain and ceramic crowns rarely cause any issues. Always inform your MRI radiographer of any dental restorations before your scan.

What Is a Dental Crown and What Materials Are Used?

A dental crown is a tooth-shaped cap placed over a damaged, weakened, or heavily restored tooth to protect it and restore its function and appearance. Crowns are custom-made to fit your individual tooth and are permanently cemented in place by your dentist.

The material used to construct your crown can vary considerably depending on clinical requirements, aesthetic preferences, and your dentist's recommendation. The most common crown materials include:

Porcelain-fused-to-metal (PFM): A metal substructure covered with a layer of tooth-coloured porcelain. This was the most widely used crown type for many years.
Full ceramic or full porcelain: Made entirely from dental ceramic materials with no metal content. Increasingly popular for their natural appearance.
Zirconia: A high-strength ceramic material that is entirely metal-free. Zirconia has become a widely used material in contemporary dentistry.
Full metal (gold or base metal alloy): Less common today but still used in certain clinical situations, particularly for back teeth where strength is paramount.

Understanding which material your crown is made from is the most important factor when considering how it may interact with airport scanners or MRI equipment. If you are unsure which material was used for your crown, your dentist can confirm this from your clinical records.

If you would like to explore your options, you can learn more about dental crown treatments available at our London clinic.

Dental Crowns and Airport Security Scanners

One of the most frequently asked questions from patients with dental restorations is whether their crown will set off the metal detector at an airport. The short answer, for the vast majority of patients, is no — and even in the rare cases where a scanner does detect something, the process is typically straightforward.

How Airport Metal Detectors Work

Airport security uses a combination of walk-through metal detector archways and full-body imaging scanners. Walk-through metal detectors work by generating a low-level electromagnetic field. When a metallic object passes through this field, it disrupts it and triggers an alert.

Will a Metal Crown Set Off the Alarm?

The metal components used in dental crowns are generally quite small in mass and volume. For this reason, they very rarely trigger standard airport walk-through metal detectors. Even full metal crowns or porcelain-fused-to-metal crowns typically do not contain sufficient metal to activate an alarm.

Full-body imaging scanners (the millimetre-wave or backscatter X-ray type) may occasionally reveal dental work as an anomaly on the scan image, but security staff are well accustomed to this and it does not typically result in anything more than a brief explanation.

Practical advice for air travel:

There is no need to request a letter from your dentist specifically for airport security regarding a dental crown.
If you do experience any queries from security staff, calmly explaining that you have a dental restoration is usually sufficient.
Porcelain and ceramic crowns contain no metal and will not interact with metal detectors at all.

Dental Crowns and MRI Scans: What You Need to Know

MRI (Magnetic Resonance Imaging) scans use a powerful magnetic field and radio waves to produce detailed images of the body's internal structures. Unlike airport security scanners, the question of dental crowns and MRI scans requires a slightly more nuanced answer — particularly in relation to patient safety and image quality.

Are Dental Crowns Safe During an MRI?

For most patients with dental crowns, MRI scans can be performed safely. Here is what the evidence and clinical guidance generally indicates:

Porcelain and ceramic crowns (including zirconia): These are entirely metal-free and pose no known risk during an MRI scan. They do not interact with the magnetic field and are considered MRI-safe.

Porcelain-fused-to-metal crowns: These contain a metal substructure. However, the alloys used in dental restorations are typically non-ferromagnetic (meaning they are not attracted to magnets in the same way iron-based metals are). Because of this, they are generally considered safe for MRI, though they may cause minor artefacts (small distortions or shadows) in the scan images around the area of the mouth and jaw.

Full metal crowns (gold or base metal alloys): Gold is non-ferromagnetic and is generally considered safe for MRI. Some base metal alloys may contain small amounts of ferromagnetic materials, though the amounts used in dental restorations are typically very small.

Artefacts on MRI Images

Even when a crown is considered MRI-safe in terms of patient safety, it may still create artefacts — visual distortions — in the scan image. This is most relevant when the scan area being imaged is close to the jaw or skull. If you are having an MRI of your head, neck, or brain, the radiographer should be informed of your dental restorations so they can account for this when interpreting the images.

Always Inform the MRI Team

It is considered best practice — and standard safety protocol — to inform the MRI radiographer and the requesting clinician of all dental restorations before your scan. This includes crowns, bridges, implants, and any other metalwork. Most MRI centres include questions about dental work on their pre-scan safety screening forms.

The Clinical Science Behind Dental Crown Materials

To understand why different crown materials behave differently in these situations, it helps to have a basic understanding of the materials science involved.

Ferromagnetic vs Non-Ferromagnetic Metals

Metals can be broadly divided into ferromagnetic and non-ferromagnetic types. Ferromagnetic metals — such as iron, nickel, and cobalt — are attracted to magnetic fields and can behave unpredictably in a strong MRI magnet. Non-ferromagnetic metals, such as gold, titanium, and most dental alloys, do not have this property.

The alloys used in dental crown fabrication are carefully chosen by dental material scientists and are typically composed of combinations such as:

Gold-based alloys (gold, platinum, palladium)
Base metal alloys (chromium-cobalt, nickel-chromium — though nickel alloys are less commonly used today due to sensitivity concerns)

Most dental alloys used in crown construction have been extensively tested and are classified as MRI-compatible, meaning they do not pose a direct safety risk in the MRI environment. This is distinct from MRI-safe, which refers to a higher level of certainty that an implanted device poses no risk whatsoever.

Why Does This Matter for Image Quality?

All metals — even non-ferromagnetic ones — can distort the local magnetic field in a small area around them. This is because of a phenomenon known as magnetic susceptibility. The result is that on the MRI image, there may be a small area of signal loss or distortion near the crown. In most cases, if the area being scanned is not the jaw or skull, this is clinically insignificant.

Dental Implants, Bridges, and Other Restorations: How Do These Compare?

Whilst this article focuses on dental crowns, patients often have other restorations and may be wondering how these differ:

Dental implants: Titanium dental implants are generally considered MRI-compatible and do not typically pose safety risks. However, they can create larger image artefacts than crowns. Always inform your medical team if you have implants.

Dental bridges: A bridge may incorporate multiple crowns and a pontic (false tooth). The same principles apply as for individual crowns. If you are considering replacing missing teeth, you can learn more about dental bridge options to understand which materials may be most appropriate.

Orthodontic braces: Fixed metal braces are more likely to cause MRI artefacts and may occasionally pose concerns depending on the type of wire used. This is separate from the crown discussion but worth noting if you have multiple restorations.

Amalgam fillings: Silver amalgam fillings also contain metals and can similarly cause minor MRI artefacts, though they are generally considered safe for MRI scanning.

When to Seek Professional Dental or Medical Advice

Whilst the information above is intended to be reassuring for the majority of patients, there are specific situations where it would be appropriate to consult your dentist or the relevant medical team before proceeding:

If you are unsure what material your crown is made from: Contact your dental practice and ask them to check your clinical records. They should be able to provide details of the materials used.
If you are scheduled for an MRI scan of the head, neck, brain, or jaw area: Inform the MRI radiographer and requesting clinician in advance. They may wish to consult with a radiologist or specialist.
If you have multiple metallic restorations or a complex dental history: A brief discussion with your dentist can help ensure you have accurate information to share with the MRI team.
If your crown has recently become loose, damaged, or painful: This is unrelated to the scanning question but is a clinical concern in its own right. A loose crown should be assessed by a dentist promptly to avoid further damage to the underlying tooth.
If you experience any jaw discomfort, altered bite, or dental pain following a recent procedure: These symptoms merit a professional dental evaluation.

It is worth emphasising that the MRI facility will conduct a thorough safety screening assessment before your scan. Their screening questionnaire will include questions about dental restorations, and their clinical team are experienced in assessing these on a case-by-case basis.

Prevention and Maintaining Good Oral Health With a Dental Crown

Having a dental crown does not mean your dental care routine should change dramatically, but there are some practical steps that can help maintain the longevity and health of your restoration:

Daily oral hygiene: Continue to brush twice daily using fluoride toothpaste. A crown protects the visible portion of the tooth, but the margin where the crown meets the natural tooth and gumline can still be vulnerable to plaque accumulation and gum disease if not cleaned properly.

Flossing around crowns: Use dental floss or interdental brushes carefully around your crown. When flossing, slide the floss in and out rather than snapping it upwards, which could dislodge a crown over time.

Avoid excessive biting forces: Chewing extremely hard foods, ice, or biting non-food objects can place stress on your crown and the underlying tooth structure.

Regular dental check-ups: Routine check-ups allow your dentist to assess the condition of your crown, the surrounding gum tissue, and the tooth underneath. Most crowns are designed to last many years with proper care, but they are not a permanent lifetime restoration for every patient.

Night guards: If you grind your teeth (bruxism), a custom-fitted night guard may be recommended to protect your crown and other teeth from excessive wear forces.

For broader guidance on looking after your teeth and restorations, the oral health advice resources on our website may be helpful.

Key Points to Remember

Dental crowns rarely trigger airport metal detectors due to the small amount of metal involved, and porcelain or ceramic crowns contain no metal at all.
Most dental crowns are considered MRI-compatible and can be safely scanned, though the specific material should be confirmed with your dental team.
Always inform your MRI radiographer of any dental restorations before your scan — this is standard practice and part of the pre-scan safety screening.
Metal crowns may create minor artefacts in MRI images near the jaw or skull area, though this does not necessarily affect patient safety.
Knowing your crown material is valuable information — if you are unsure, your dentist can check your clinical records.
Regular dental check-ups remain important even after a crown is placed, to monitor the restoration and surrounding oral health.

Frequently Asked Questions

Will my dental crown set off the metal detector at airport security?

In the vast majority of cases, dental crowns do not trigger airport metal detectors. The amount of metal in even a full metal crown is typically too small to activate standard walk-through archway detectors. Porcelain and ceramic crowns contain no metal and will not interact with metal detectors at all. If you are ever questioned by security staff, a calm explanation that you have a dental restoration is usually all that is needed. There is generally no requirement to carry documentation from your dentist for airport security purposes.

Is it safe to have an MRI scan if I have a dental crown?

For most patients, MRI scans are considered safe to perform even with dental crowns in place. The alloys used in dental restorations are predominantly non-ferromagnetic and are generally classed as MRI-compatible. However, it is important to always inform the MRI radiographer and the clinical team about all dental restorations before your scan. If your crown is in the area being imaged, they may wish to note this for image interpretation purposes. The MRI facility's pre-scan safety screening will guide this process.

Can a dental crown cause distortion on an MRI scan image?

Yes, metallic components in dental crowns can occasionally cause small artefacts — visual distortions — on MRI images. This is more likely to be relevant if the MRI scan is of the head, jaw, neck, or brain area. Whilst this may occasionally affect image clarity in the immediate area around the crown, it does not typically compromise the safety of the scan or the diagnostic value of imaging performed in other body regions.

Does the type of crown material affect whether it is MRI-safe?

Yes, the material matters. Porcelain and zirconia crowns are entirely metal-free and pose no known concerns during MRI scans. Gold-based alloy crowns are generally considered MRI-compatible because gold is non-ferromagnetic. Porcelain-fused-to-metal and base metal alloy crowns also have a generally acceptable safety profile for MRI, but specific alloys vary. If you are uncertain which material your crown is made from, contact your dental practice who can confirm this from your clinical records before your scan appointment.

Do I need to tell my dentist before having an MRI scan with a crown?

It is advisable to let your dentist know if you have any concerns, particularly if you are unsure of your crown's material. Your dental team can provide information about the materials used in your restoration that may be helpful to share with the MRI radiographer. In most cases, the MRI facility's pre-scan screening will be the primary clinical checkpoint, but having accurate dental records to refer to is always beneficial.

What should I do if my dental crown feels loose or uncomfortable before a scan?

If your crown feels loose, has shifted, or is causing discomfort, you should contact your dental practice before any planned scan or travel. A loose crown can expose the underlying tooth structure and requires prompt dental assessment. This is a separate clinical concern from the scanning question and should not be left untreated. A dentist will be able to assess whether the crown needs recementation or further investigation.

Conclusion

For most patients, having a dental crown fitted does not mean you will face any significant difficulties passing through airport security or undergoing a medical MRI scan. The materials used in modern dental crowns — particularly porcelain, ceramic, and zirconia — are metal-free and raise no concerns in either of these scenarios. Even metal-containing crowns are generally made from non-ferromagnetic alloys that are unlikely to trigger airport detectors and are typically considered compatible with MRI imaging.

That said, the most important step is always to inform the relevant clinical or security teams of your dental restorations. For MRI scans in particular, this is a standard safety requirement and allows the radiography team to make informed decisions about scan protocols and image interpretation.

If you are unsure about your crown material or have concerns about an upcoming scan, speaking with your dental practice is a sensible first step. Dental symptoms and treatment options should always be assessed individually during a clinical examination.

Can You Go Through Airport Security or Have an MRI Scan With a Dental Crown?