Yes. The crown itself does not cause cavities, but the natural tooth underneath it can develop cavities, usually at the edge where the crown meets the tooth. The risk increases if there is bacterial plaque, gum recession, a leaky margin, or an old or damaged crown.
Why does tooth decay occur if the tooth is covered?
The crown covers a large portion of the tooth, but at the margin there is a transition zone between the restoration and the tooth structure. This area must be cleaned very thoroughly.
If plaque builds up or the margin is no longer tight, bacteria can damage the natural tooth. A crown does not make the tooth immune to decay.
How can you tell if there's tooth decay under a crown?
Sometimes there are no symptoms at first. Other times, sensitivity, pain, an unpleasant taste, a local odor, gum inflammation, or visible changes at the edge of the crown may occur.
If the tooth has had a root canal, tooth decay can develop without the typical nerve pain, which makes regular checkups even more important.
Does a crown that smells bad automatically mean I have a cavity?
No. The odor can also come from plaque, trapped food, gum inflammation, or poor oral hygiene. However, if it persists around a single crown, it’s worth checking the fit and the health of the tooth.
Don't try to mask the problem with mouthwash alone. The mechanical or biological cause must be identified.
Can tooth decay be seen on an X-ray?
X-rays can help assess cavities and the root, but the material of the crown and the location of the lesion may limit what can be seen. A clinical examination remains important.
The doctor may recommend a retroalveolar X-ray and, in certain situations, additional tests.
Should a crown be removed if there is tooth decay?
In many cases, the crown must be removed in order to properly clean out the cavity and assess the tooth’s structure. If the tooth can be restored, the necessary treatment is performed, followed by a new restoration.
If the lesion is small and accessible, there are situations in which the approach may differ. The decision depends on the location and how much of the tooth is affected.
Can the tooth still be saved?
Often, yes, if there is enough healthy tooth structure remaining and the root has a good prognosis. If the lesion is very deep, root canal treatment or retreatment may be necessary.
In cases where the tooth is fractured or destroyed well below the gum line, extraction may be an option. Early evaluation increases the chance of saving the tooth.
How long does a crown last before it needs to be replaced?
There is no universal expiration date. A crown can last for many years if it is properly fitted, the tooth is healthy, and oral hygiene is good. Other crowns may need to be replaced sooner due to cavities, fractures, gum recession, or cosmetic issues.
More important than the number of years is the condition of the crown during the checkup.
What type of crown can be used for a replacement?
SmileCity offers metal-ceramic crowns, monolithic zirconia, and Emax ceramic crowns. The material is selected based on the tooth’s position, mechanical stress, and aesthetic goals.
View current prices for crowns and prosthetic treatments.
How can you prevent cavities at the edge of the crown?
- brushing twice a day;
- interdental cleaning tailored to the area;
- professional cleaning services when recommended;
- periodic inspections;
- treatment of xerostomia and the increased risk of tooth decay;
- Do not delay if you notice a chipped edge or a loose crown.
A good crown requires the same care as the surrounding natural teeth.
When should you see a dentist sooner rather than later?
Pain, swelling, a loose crown, pus, or a fracture are reasons to schedule an appointment right away. If a crown falls out completely, keep it and contact the clinic—do not try to reattach it with household adhesives.
Even if there is no pain, a crown that appears to be coming loose should be examined before it causes the tooth to become sensitive and fracture.
Why is interdental hygiene so important around dental crowns?
A toothbrush cleans accessible surfaces, but plaque can accumulate in the area between the teeth and the edge of the crown. Flossing, interdental brushes, or other methods recommended by your dentist can reduce the risk of inflammation and marginal caries.
For bridges, there are special cleaning techniques for the underside of the bridge deck that must be learned after the structure has been set in concrete.
What happens if you put off replacing a decayed crown?
A small lesion can progress beneath a restoration without being visible. If too much tooth structure is lost, treatment becomes more complex, and sometimes the tooth can no longer be restored predictably.
Early detection can make the difference between a new crown and additional treatments such as root canal therapy, reconstruction, or extraction.
How do you prepare for your appointment, and what information should you bring?
Make a note of when the problem started, what symptoms you’re experiencing, what dental treatments you’ve had in that area, and what medications you’re currently taking. If you have X-rays, CBCTs, medical reports, or documents regarding implants and previous dental work, bring them to your appointment. Tell your dentist if you smoke, have any allergies or chronic conditions, or are undergoing treatments that could affect healing. It’s also helpful to specify what concerns you most: pain, duration, aesthetics, cost, or the number of procedures. An effective consultation isn’t just about receiving a diagnosis—it’s about understanding your options, the sequence of steps, and the reasons why a particular approach is recommended. Ask for clarification if a term is unclear, and ask what happens if you choose to postpone treatment or opt for an alternative. This way, you can make an informed decision and accurately compare your options, rather than relying solely on the price of a single procedure.
Frequently Asked Questions
Can a zirconia crown cause cavities?
Zirconia does not cause cavities, but the natural tooth beneath the crown may develop a cavity at the edge.
If the tooth has had a root canal, can I still feel the cavity?
You may not experience the typical symptoms, which is why the recommended tests and X-rays are important.
Can the crown be repaired without being replaced?
Some minor defects can be managed, but decay under a crown often requires removal of the restoration.
Why has the edge of the crown turned black?
There may be several causes, ranging from subgingival tissue to tooth decay or gum recession. An evaluation is necessary.
Should I have my crowns checked even if they don't hurt?
Yes. Minor problems may be asymptomatic at first.