Table of Contents
Zirconia crowns are widely known for their outstanding durability, natural appearance and long-term reliability. They are among the strongest types of dental crowns used in the UK. However, many patients still wonder: “Can a zirconia crown crack?”
While zirconia crowns are highly resistant, they are not completely indestructible. This guide explains how cracks occur, how to spot them, and what to do if your crown becomes damaged.
Can a Zirconia Crown Crack? Understanding the Possibility
Yes, a zirconia crown can crack, but it is far less likely compared to porcelain or ceramic crowns. Zirconia is one of the toughest materials in modern dentistry, and full-contour zirconia crowns are especially famous for their strength.
Cracking usually happens due to extreme force or underlying dental issues, not because the material is weak.
How Strong Are Zirconia Crowns?
Zirconia crowns have a flexural strength between 900–1200 MPa, which is significantly stronger than traditional porcelain (around 400 MPa). This makes zirconia highly resistant to:
- Heavy biting forces
- Wear and abrasion
- Temperature changes
- Everyday chewing
Despite this strength, excessive forces—especially from grinding or accidental trauma—can still damage them.
Why Do Zirconia Crowns Crack or Chip?
Although uncommon, a zirconia crown may crack due to:
- Teeth Grinding (Bruxism)
Constant grinding places extreme pressure on the crown, increasing the risk of fractures over time.
- Improper Crown Fit or Thickness
If the crown is too thin or improperly shaped, it may be more vulnerable.
- Chewing Extremely Hard Foods
Biting items like ice, hard sweets, fingernails or nutshells can cause damage.
- Trauma or Accidents
A sudden impact—such as a fall or sports injury—may crack even the strongest materials.
- Manufacturing or Laboratory Issues
If zirconia is not milled or sintered correctly, microscopic weak spots may form.
Is a Cracked Zirconia Crown Common?
No.
Compared to other crown materials, zirconia crowns are the least likely to crack. Most UK dentists prefer zirconia for:
- Back teeth restorations
- Patients with strong bite forces
- Individuals with a history of cracked crowns
Cracks are possible but definitely not common.
Signs Your Zirconia Crown May Be Cracked or Damaged
It can be difficult to notice a zirconia crown fracture because the material doesn’t always show clear lines. Look for:
- Sharp edges on the crown
- Sudden sensitivity
- Pain when chewing
- A visible hairline crack
- A slight movement or looseness
- Food getting stuck around the crown
- Unusual sound when biting
If you suspect a problem, see your dentist for an examination and X-ray.
Can a Zirconia Crown Break While Chewing?
It is rare, but possible.
Zirconia crowns can withstand heavy pressure, but chewing on extremely hard objects or grinding your teeth can create microfractures that grow over time.
Avoid biting:
- Ice
- Hard boiled sweets
- Bones
- Nuts (with shell)
- Metal bottle caps or pens
These habits put unnecessary stress on the crown.
Can Hairline Cracks in Zirconia Crowns Get Worse?
Yes.
A hairline crack can slowly expand due to repeated chewing forces. If untreated, it may eventually lead to:
- Crown splitting
- Crown detaching
- Pain or discomfort
- Bacterial leakage into the tooth
Early detection prevents more serious problems.
Can a Cracked Zirconia Crown Be Repaired or Does It Need Replacement?
Unlike porcelain, zirconia cannot be repaired reliably once it cracks.
In almost all cases, the dentist will recommend replacing the crown to prevent further damage or bacterial leakage.
What Should You Do If Your Zirconia Crown Cracks?
Follow these steps:
- Avoid chewing on the affected side
- Contact your dentist immediately
- Take a photo if a visible crack is present
- Do not try to glue the crown yourself
- Schedule an examination and X-ray
Your dentist will determine whether replacement is required.
How Dentists Fix or Replace Damaged Zirconia Crowns
A dentist will typically:
- Inspect the crown visually
- Take X-rays
- Evaluate bite alignment
- Remove the damaged crown
- Take digital or physical impressions
- Create a new custom zirconia crown
- Cement the new crown securely
Modern digital dentistry allows for faster and more accurate replacements.
Prevention Tips to Stop Zirconia Crowns from Cracking
- Wear a night guard if you grind your teeth
- Avoid chewing hard foods
- Prevent bad habits like nail biting
- Maintain regular dental check-ups
- Ensure your bite alignment is checked periodically
- Treat gum disease or infections promptly
With proper care, zirconia crowns can last 10–20 years or longer.
FAQ – Can a Zirconia Crown Crack?
Can a zirconia crown crack?
Yes, but it is rare. Zirconia is one of the strongest dental materials.
What causes a zirconia crown to crack?
Grinding, trauma, hard foods, improper fit or manufacturing issues.
Can chewing hard foods crack a zirconia crown?
Yes. Foods like ice and hard sweets can increase the risk.
How can I tell if my zirconia crown is cracked?
Look for sensitivity, sharp edges, visible lines or pain when chewing.
Does a cracked zirconia crown need to be replaced?
Almost always — zirconia cannot be reliably repaired.
Are zirconia crowns stronger than porcelain when it comes to cracking?
Yes. Zirconia is significantly stronger and more resistant to chipping.
Can grinding or clenching crack a zirconia crown?
Yes. Bruxism is one of the most common causes of crown fractures.