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Reviewed by Dr. Drew Endicott, Endicott Dental, Broken Arrow, OK. Updated September 23, 2026.
Craze lines are not bad for your teeth. They are hairline cracks in the outer enamel only, they don’t reach the dentin or nerve, and they almost never get worse on their own; most adults have a few and never know. The exceptions are a line that starts to catch your fingernail, turns dark and deepens, or comes with pain when biting. Those are signs of a true crack, not a craze line, and need a dental exam.
What bothers most people is how craze lines look, because they pick up coffee, tea and tobacco stain and show as thin brown or grey lines on the front teeth. That part is fixable: teeth whitening lightens the stain in the lines, and bonding or veneers cover them entirely. Here is how to tell a craze line from a crack, what causes them, and which fix fits.
- Are craze lines bad? No. Enamel-only, no pain, no treatment needed.
- Do they get worse? Rarely. Grinding, ice-chewing and hot-cold cycling can add more lines, but they stay superficial.
- When to worry: a line that catches your nail, darkens and deepens, or hurts when you bite.
- How to hide them: whitening for stain, bonding for a few lines, veneers for many.
What Are Craze Lines, and Why Do They Look Like Cracks?
Craze lines are vertical cracks in your tooth’s enamel, the hard outer shell that protects the living interior, and they can be treated with resin. They are very shallow, so they don’t penetrate the living portion of the tooth — the dentin and the pulp.
The best way to think of craze lines is to think of antique porcelain. You’ve probably seen such porcelain with what looks like thousands of cracks covering the surface. Those cracks don’t mean the porcelain is unusable. It means it’s showing its age and wear, which can worsen if not addressed with proper dental care.
The same can be said for craze lines, as they are often superficial and can be treated. The hairline cracks in teeth show the age and wear of your tooth’s enamel, which can get worse over time. These lines are usually invisible at first, but over time they can be stained and show up better. That’s why it’s important if you see craze lines to take special care in keeping your teeth clean. Otherwise, plaque and bacteria can penetrate the cracks and cause cavities, which can lead to a dental emergency.
What does a cracked tooth look like compared to craze lines, and how can a dentist help? A crack will be deeper, potentially compromising your tooth enamel. You may even be able to see the interior of the tooth. A crack in a tooth is usually very visible compared to the nearly invisible lines, affecting the aesthetics of your front teeth. Your teeth also likely will become sensitive because the crack exposes the dentin and pulp, where the tooth’s nerves are located, leading to potential tooth sensitivity. Craze lines don’t go deep enough to make your teeth more sensitive.
What Causes Craze Lines in Teeth?
Craze lines can be caused in several ways. Often, those lines are caused by biting or chewing down on something hard, such as tortilla chips or hard candy. They can also be caused by bad chewing habits, such as chewing on pencils or pens, fingernails, or other objects. Craze lines can also be caused by bruxism or teeth grinding, which can lead to a crack in your tooth.
Craze lines don’t necessarily mean all of your enamel is weak, but patients who know they have thin or weak enamel may be more susceptible to craze lines. However, you could have great enamel and still get a line from biting down on something wrong. Craze lines do tend to happen as you age, and normal wear and tear weakens your enamel.
If you’re concerned about your enamel, talk to us at Endicott Dental. When we examine your teeth during your semi-annual visits, we can determine whether you need to take steps to strengthen your enamel and prevent craze lines. Weak enamel can also lead to cavities and tooth decay if dental hygiene is not maintained. We have ways to help, including a fluoride sealant we can put on your teeth to help strengthen your enamel.
Craze Line vs. Cracked Tooth: How to Tell
- Craze line: visible as a thin vertical line in normal light, no pain, stays the same for years, no treatment needed.
- Cracked tooth: often needs a dental light to see, hurts when you bite or release, sensitive to cold, deepens over time, treated with a crown or root canal.
How to Make Craze Lines Less Visible
How do you fix craze lines? It’s not necessary to fix them unless the crack grows or gets a cavity. Most of the time, craze lines are just an aesthetic thing. They may not look great, but they won’t harm the way your tooth functions according to your dentist.
Over time, craze lines can become stained and more visible. If you don’t like the look of that, we have ways to make craze lines less visible or cover them completely. We offer several Our cosmetic dentistry services can help address issues like craze lines and cracks in your tooth, ensuring better dental care. that can reduce or eliminate the appearance of craze lines.
Teeth Whitening
Teeth whitening can eliminate the stains on your teeth and in the craze lines and make them far less visible. After teeth whitening, patients usually have to look very closely to be able to see even a hint of the lines. Teeth whitening is one of the easiest treatment options to deal with them, and it can make the rest of your smile look amazing! Learn more about professional teeth whitening in Broken Arrow.
Bonding
Dental bonding involves brushing a special coating on your teeth that can cover stains, cracks, and chips. Our dental bonding can make your teeth look like new and restore your tooth enamel. See our cosmetic dentistry options.
Crowns
A dental crown is essentially a cap that goes over your entire tooth to cover cracks, breaks, or chips. A crown is often used to protect a broken tooth so it doesn’t have to be pulled. It can also cover craze lines and deeper cracks in your enamel and prevent them from damaging your tooth further. Read about dental crowns.
Veneers
Veneers are thin shells that cover the front surface of your tooth. Our veneers give your teeth a new look and are often used to cover stains, chips, cracks, and tooth wear. Veneers do require thinning the enamel so they fit properly, so it’s a multi-appointment process. But the end result is stunning! Read about dental veneers.
Craze Lines FAQ
Are craze lines bad?
No. They are shallow cracks in the enamel that don’t reach the inner tooth, and they don’t weaken the tooth or need treatment.
Do craze lines get worse over time?
Usually not. They stay the same depth for years. Clenching, grinding, chewing ice and rapid hot-cold changes can create more lines, but the lines stay superficial.
How can I tell a craze line from a cracked tooth?
A craze line is painless and visible as a thin vertical line in normal light. A cracked tooth hurts when you bite or release, is sensitive to cold, and the crack deepens over time. If you have any pain, have it checked.
Can craze lines be removed?
They can’t be erased, but they can be hidden. Whitening removes the stain that makes them show, bonding covers a few lines, and porcelain veneers cover many.
Why do my craze lines look brown?
Coffee, tea, red wine and tobacco settle in the grooves and stain them. A professional cleaning and whitening lifts most of that stain.
Craze Lines Care in Broken Arrow, OK
Craze lines may not look great, but they’re usually part of the normal wear and tear your teeth endure throughout your lifetime. As long as you feel no pain from your teeth, you can live with craze lines as simply a cosmetic change. If you want your teeth to look normal, Endicott Dental has several options that can make your teeth look good as new!
Schedule an appointment with your dentist to discuss treatment options. with Endicott Dental in the Broken Bow, OK, area to see what we can do for you and your craze lines. You deserve to have a smile you can be proud to show off, and Endicott Dental can help you get just that!
