Hairline Tooth Fractures (Cracks): Causes, Symptoms, and Treatment

Hairline Tooth Fractures (Cracks): Causes, Symptoms, and Treatment
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Hairline Tooth Fractures (Cracks): Causes, Symptoms, and TreatmentClinical Content Reviewed by Dr. Jay Khorsandi, DDS
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Table of Contents

  1. What are Hairline Fractures?
  2. Causes
  3. Symptoms
  4. Diagnosis
  5. Treatment
  6. Frequently Asked Questions
  7. References

Having a hairline tooth fracture can be a serious ordeal, especially when the condition is severe. Various factors such as age can cause tooth fractures.

It might take some time for symptoms to show, but it is impossible to miss them when they do. Your front teeth and at the back of the lower jaw are the most common locations for cracks. But fear not: your teeth should go back to normal after treatment.

Cracked tooth syndrome primarily affects adults between ages 30-50, with a 31-74 percent incidence rate. See an endodontist as soon as symptoms start to show.

What Are Hairline Fractures?

Also known as cracked tooth syndrome, hairline fractures present with the appearance of obvious cracks in your teeth. Hairline teeth fractures can be mild to severe. Children and older people are at a higher risk of developing fractured teeth.

Tooth fractures can happen on the crown above the gum or in the roots below the gum. Hairline fractures affect some or all of the layers in the crown and root. They can occur in four ways:

Cracked tooth.
This hairline tooth fracture runs from the biting edge towards the root. In some cases, the fracture may reach the gum line. The damage only occurs on the internal tissue of the tooth.
Split tooth.
If a cracked tooth goes untreated, it can develop into a split tooth. A fracture of this kind starts from the root to the biting surface.
Craze lines.
Craze lines are types of fractures that affect only the outer enamel of teeth. They are painless and common with adults. There is no need to rush for treatment with craze lines, as they are not severe.
Cracked cusp.
A cusp refers to the biting surface of a tooth. Damaged cusps result in broken teeth. Cracked cusps are often painful, especially when biting.


The most significant risk of fractured teeth is growing older. Teeth cracks are common in children and adults 50 years old and older.

Biting into hard things such as candy or popcorn can also cause hairline tooth fractures. Additionally, chewing gum or ice can result in fractured teeth.

If you experience teeth grinding (Bruxism), there is a strong likelihood you will suffer from fractured teeth. Also, heavy impact on teeth from falls, bike accidents, and violence may result in fractured teeth.

Additionally, cavities enhance the possibility of having fractured teeth even when there is minimal trauma.


Symptoms of fractured teeth usually show up when you are biting or chewing. Frequent dental checkups can help reveal signs before they manifest. That said, here are the common symptoms:

  • Fleeting pain: You will have a toothache when chewing or biting using cracked teeth.
  • Swelling: Swelling occurs in the gum surrounding the affected tooth. It could last a while when an abscess forms in the tooth as well.
  • Sensitivity: You will display sensitivity to extreme temperature and products heavy in sugar.


The first step in diagnosing a hairline tooth fracture is to identify the symptoms. You can also diagnose yourself by looking for the signs, but a healthcare provider should have the final say.

Usually, dentists ask questions about specific activities contributing to fractured teeth.

They also ask about your dental history to help place the origins of the fracture, which eventually helps with treatment. After that, the dentist will look for broken or avulsed teeth.

Dentists use a stick for patients to bite down on to find pain areas and inspect teeth for crack lines. A gum examination follows to examine the severity of a crack.

Transillumination will show fractures in the teeth. The dentist will then stain the affected tooth with a dye to enhance X-ray imaging. Periodontal probing, which involves checking if the tools can stick in the crack, is the final step in the diagnosis.

X-ray imaging works when the crack is parallel to the beams to allow penetration. Still, there is always vertical bone loss near the visible root if a break has been present long enough. In that case, applying a magnifying glass or bright light along the dye line can help find the crack.

Treatment and How to Repair

You can start treatment for a fractured tooth at home. Urgent care should focus on relieving pain to give you enough time to reach a dentist. Before you get to the dentist, do the following:

  • Ice the outside of your mouth to reduce swelling.
  • Use a salt and water solution to rinse your mouth. The salt solution is an antiseptic and will treat any wounds while killing microbes.
  • Take painkillers and anti-inflammation to reduce pain and swelling

A dental health expert will treat the tooth according to the damage. It is important to gather any available remedies to avoid nerve damage and abscess growth in a cracked tooth.

Dentists treat fractured tooth in several ways. They include:

Bonding involves filling a tooth fracture with resin. It typically repairs small chips off the biting edge to restore the shape of a tooth.
A dental care expert would recommend removing a tooth when the damage of the fracture is too severe. Extraction is the surest way of completely getting rid of a tooth fracture and any issues that might come with it.
Root canal.
Dentists use root canal treatment when a crack extends to the pulp. Removing damaged pulp prevents further tooth weakening.
Crowning is placing a porcelain or ceramic cap over a cracked tooth. It is an alternative when there isn’t sufficient support for veneers.
Dentists use veneers when a good portion of the tooth is left to provide support. It involves placing a thin covering of porcelain or plastic over the front of a fractured tooth.
Cosmetic contouring.
Cosmetic contouring involves polishing and rounding a broken tooth.


Can a hairline tooth fracture heal itself?
A hairline tooth fracture can heal over time, but only if the damage is insignificant. It heals through the process of remineralization. Generally, a hairline tooth fracture can heal itself if it occurs on the outer enamel. Typically, this type of crack is painless, providing it is not severe.
How do you fix a hairline crack in your teeth?

That can happen in four ways. One is bonding which involves filling the fracture with resin. Similarly, the medical practitioner can perform crowning by adding a cap over the crack.

Alternatively, your dentist can fix it through a root canal, especially if the crack stretches deep to your pulp. However, extraction is the best alternative if the damage is extreme.


Bruxism. (May 2021). Cleveland Clinic.

Cracked Teeth. (2021). American Association of Endodontist.

Cracked Tooth Diagnosis and Treatments: An Alternative Paradigm. (June 2015). European Journal of Dentistry.

Dental Bonding. (October 2018). Cleveland Clinic.

Fractured Tooth (Cracked Tooth). (June 2021). Cleveland Clinic.

The Obvious and The Obscure: Steps for Crack Detection and Confirmation. (Summer 2008). American Association of Endodontists.

Toothache. (March 2020). Cleveland Clinic.

Cracked tooth syndrome: Overview of literature. (December 2015). International Journal of Applied Basic Medical Research.

Disclaimer: This article is intended to promote understanding of and knowledge about general oral health topics. It is not intended to serve as dental or other professional health advice and is not intended to be used for diagnosis or treatment of any condition or symptom. You should consult a dentist or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment.