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Craze Lines - Guide

Updated: May 15

Craze lines are superficial thin lines that appear on the surface of your tooth enamel. They are a cosmetic issue and not a dental emergency. They're often described as stress lines or hairline cracks in your teeth. They may resemble a cracked tooth but they are NOT the same. They are often asymptomatic with no pain.

They could be caused by a variety of factors and there are treatments available but fixing it is not necessary unless you elect to do so. We will go everything there is to know about craze lines in your teeth and what you should do to take care of them.

To get you started, here is a picture of a craze line on an upper front tooth #9 but you can also see it on #8 which is to the far left in the photo as well. They are very faint vertical lines.

Table of Contents:

What do craze lines in teeth look like?

Craze lines literally look like a vertical crack extending towards the entire length of the tooth. The size and position of the lines may vary from person to person. They're most often found on front teeth but they can also appear on back teeth as well.

Most people won't even notice that they are there unless they look really closely into the mirror. In fact, the only people who tend to know that craze lines are there is the person themselves and no one else!

Here are some common descriptions of them:

  • Stress lines in teeth

  • Hairline cracks in teeth

  • Vertical crack in tooth but not an actual crack

  • Crack in tooth enamel

  • Small cracks in tooth enamel

Here are some photos of craze lines on the front teeth:

Here is a photo of a craze line on a premolar, which is a back tooth just to demonstrate that they're not just on front teeth!

craze line premolar

What they feel like: If you run your fingernail across the craze lines, sometimes you can feel indentation in the enamel but other times you can't. It depends on how deep the stress lines are. The vast majority of time they are so superficial that they cannot be felt.

Note: These hairline cracks can also appear on dental crowns and veneers. They are not exclusive to your natural dentition.


Craze lines vs crack in tooth

The two main differentiating factors between a craze line and a cracked tooth are the depths of the stress lines and the urgency of required care.

Depth of crack in the tooth

Craze lines are very superficial crack lines that do not extend beyond the enamel. They are so shallow that you can't even feel them if you run your fingernail across it most of the time.

A cracked tooth on the other hand does NOT have a superficial crack. These stress lines or crack lines extend beyond the enamel and into the dentin. The very severe cracks will extend even further beyond the dentin and into the pulp. The catastrophic fractures will literally split the tooth in half!

Here are pictures of crack lines (not craze lines) that run through the entire tooth:

In case you were wondering, crack lines can even happen to root canal treated teeth. This is the reason why you NEED a crown after a root canal!

fractured molar

This is a very unfortunate outcome because the patient spent their hard earned money on the root canal but ended up developing a fracture line through the tooth. This tooth can no longer be saved and will need to be extracted.

Fortunately, craze lines are only located within the enamel and are very superficial. What that means is that they do not compromise the integrity of your tooth. They are merely cosmetic concerns.

Urgency of required care

A craze line is a cosmetic concern while a cracked tooth with a fracture line is an emergency.

Since the craze lines in teeth are not an emergency and are merely cosmetic, it means that they do not require treatment. You won't be in pain and your tooth is not in danger. However, some people do not like the appearance of the hairline cracks in their enamel and do wish to have them fixed. That of course is elective but not required.

The fractured teeth with crack lines on the other hand are emergencies and NOT cosmetic issues. The crack lines for these teeth often split the entire tooth in half meaning you no longer have a single tooth but two teeth! These teeth cannot be restored and will need to be extracted. You will also most likely be in pain if you have a fractured tooth.


What causes craze lines in teeth

There are multiple ways that craze lines can form in your teeth and here are the most common ones:

Large fillings

Large dental fillings can cause stress lines to form in your teeth. The reason is because they often do not provide enough support for your tooth. If you're seeing craze lines from large fillings, you may want to consider putting a crown on the tooth so that it doesn't become an actual crack.

Silver filling with craze lines

This tooth has a very large silver filling that is causing multiple stress lines to form. The tooth is even changing colors from the amalgam leeching out the black color! This tooth could benefit from a crown.

silver filling on premolar with 2 craze lines

This is another example of a large filling that ended up causing two craze lines. Fillings are meant to be small and not big.

Chewing trauma

If you like chewing hard foods like ice cubes and chicken bones, you may cause hairline cracks in your teeth. They form due to the hard biting pressure. There is not much you can do aside from minimizing hard foods!

Injury to mouth

Accidents which result in an injury to your mouth may end up causing you craze lines on your teeth. The most common would be tripping and falling on your face. The impact may not have been enough to crack your tooth but it did leave a superficial crack line on your enamel.

As long as your tooth is not in pain and the nerve is still healthy, you may not require any treatment. However if the tooth is in pain and it has "craze lines" the nerve may have been injured and in that case it would require treatment.

Teeth grinding

Habitual teeth grinding in the middle of the night can not only cause a lot of stress on your jaw but also on your teeth. Teeth will get worn down from grinding and its not unusual to start forming a lot of crack lines on all of your teeth.

If you are doing this, you should consult a dentist about possibly having a night guard made to protect your teeth. A mouth guard is something that you wear at night time so that you grind through the acrylic, which it is made out of instead of on your own teeth.

Bad habits

Craze lines can form not only from hard foods but also from bad biting habits. Some people bite fingernails while others like to bite into pens/pencils. If you are one of these people then you should try to find an alternative way for you to fidget.

There are toys, which can help distract your hands so that you don't nail bite such as a fidget toy.

fidget cube

Uneven bite

An uneven bite can cause occlusal trauma to your dentition. Certain teeth may be sustaining a lot more force if the bite isn't even. The only way to treat this would be to make the bite even, which requires either braces or Invisalign. Once you even out the bite, the force load will be distributed more evenly among all of your teeth.

How to fix craze lines in teeth

The only way to fix the craze lines and get rid of them is by drilling them away. After you drill away the hairline cracks, you will need to restore it with something. Here are three popular options for covering up the tooth after drilling away the stress lines.

  • Dental bonding. The most conservative treatment is to place some composite bonding to restore the drilled away craze line. The procedure for this is the exact same as getting a cavity filling except you're not drilling away tooth decay but a stress line instead.

  • Crowns. If you have multiple craze lines such as from a large dental filling, a crown may be a better option. The reason is because dental crowns will cover the entire tooth 360 degrees.

  • Veneers. For craze lines that are just on the front teeth, a more aesthetic option than bonding would be dental veneers. They are more color stable and look prettier since they are made out of porcelain. The only downside is that a veneer procedure is less conservative than a bonding.

What will NOT fix craze lines

Contrary to some claims, teeth whitening will not get rid of craze lines because they are small cracks or surface indentations on the enamel. They are not a discoloration nor are they a stain so whitening will not get rid of them.

However, if the craze line does pick up staining the whitening will help them look less noticeable. That is if they get stained. If they don't then the teeth whitening will have zero effect.

Can you fix craze lines in teeth naturally?

Unfortunately, craze lines cannot be fixed naturally nor will they go away on their own. It all has to do with the fact that these lines are superficial cracks in the enamel. The cracks will not refill back in on their own and there is no home treatment for it either.

Even the most beloved fluoride toothpaste will not be able to "repair a craze line". The only way to do it is by seeing a dentist and receive either a bonding, crown, or veneer.

Is there any way to prevent craze lines from happening?

Since craze lines can develop in a variety of ways, we can only give you generalized tips on keeping your teeth healthy.

  • Fluoride toothpaste. Make sure you're using a toothpaste with fluoride because fluoride strengthens your teeth. The way that happens is the fluoride ion replaces the hydroxyl ion and that makes the overall integrity of the tooth stronger.

  • Eat calcium. You definitely need a diet that has enough calcium because that is what keeps your teeth and bones healthy. If you recall in your childhood with all of the got milk commercials. They weren't lieing.

  • Night guard. If you grind your teeth, make sure you let your dentist know and maybe have a night guard made. This can prevent you from damaging your teeth in the middle of the night.

  • Avoid hard foods. If you have a preference for eating hard foods like bones and seafood with shells, you may want to minimize the amount of it. Always use a crab leg cracker to get to the meat instead of using your teeth. A cracked tooth is a lot more expensive than a crab leg cracker!


Craze lines may look like a fractured tooth but they are not the same. It is a cosmetic condition rather than a dental emergency. The condition is often painless and does not require any treatment at all. However some people don't like the appearance of these stress lines and do elect to have them fixed via dental procedures.

If you are concerned about craze lines, you should get a consultation with your dentist. It would be prudent to do so because you do want to rule out a fracture. Often times, a tell tale sign of a fracture over a stress line would be the presence of pain. Fractured teeth are symptomatic and will cause pain.

So if you think you have a craze line but you're having pain, it most definitely is not just a craze.

Author: Written by Dr David Chen, a long island city dentist.



David Chen 200 x 200.jpg

About the author: Dr David Chen, DDS

Hello, I'm Dr Chen and I'm an actively practicing dentist in Long Island City, NY. I graduated from Columbia University College of Dental Medicine in 2016 but prior to going to dental school I was already working in the dental field. It's been more than a decade since I first got to know dentistry and let me tell you, time flies by quickly. Since then I've developed a fondness for writing, which is how this all got started!

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Medical Disclaimer:

This blog is purely meant for information purposes and should not be used as medical advice. Each situation in your mouth is unique and complex. It is not possible to give advice nor diagnose any oral conditions based on text nor virtual consultations. The best thing to do is to go in person to see your dentist for an examination and consultation so that you can receive the best care possible.

The purpose of all of this oral health information is to encourage you to see your dentist and to inform you of what you may expect during your visit. Due to the unfortunate nature of dentistry, there isn't really any true home remedies that will get rid of dental problems. Roughly 99.99% of them require in-person intervention by a healthcare professional.

Hint: That is the reason why you can't eliminate seeing dentists in your life!

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