Some people get worried when they notice small lines running through their front teeth. However, there is usually no reason to worry if you notice them, as they might only be craze lines (a harmless, cosmetic imperfection).
‘Craze line’ is a common term in dentistry. Craze lines are vertical lines that appear superficially on tooth surfaces. They can appear on front or back teeth. The appearance of craze lines usually comes as people age. They might be translucent or appear yellow, gray, or brown.
The human enamel experiences reduction in permeability and discoloration as one ages. The visual appearance of vertical cracks and craze lines also increases with age.
Craze lines appear as tiny cracks, also called 'hairline cracks.' They affect only the outer layer of the tooth (enamel) and don't extend into the dentin (the middle layer).
Craze lines are vertical lines that look like tiny hairline cracks on the tooth enamel. They look like straight-line patterns, are shallow, and appear vertically on a tooth.
Craze lines are easy to notice, especially if you flash a light on your teeth at a particular angle. The light will reflect off the surfaces of the hairline cracks.
Craze lines can appear because teeth are exposed to stress every day. For example, years of chewing or bruxism (teeth grinding) put pressure on the teeth, potentially causing craze lines.
The following can cause the appearance of craze lines:
Craze lines on tooth enamel are a common clinical finding. Even healthy teeth can develop craze lines. However, they appear more as one advances in age. Therefore, they are extremely common in adult teeth.
Craze lines and cracks are two terms that people usually confuse for each other in dentistry. However, they do not mean the same thing.
In a post made on CDA Oasis (The Canadian Dental Association website), Dr. Mary Dabuleanu, in collaboration with Dr. Suham Alexander, gave an insight into the difference between craze lines and cracks.
According to the doctors, a craze line is a tiny crack that affects only the tooth enamel and usually doesn’t present with symptoms. Craze lines typically don't have a treatment need unless for an aesthetic purpose.
On the other hand, a crack affects not just the outer enamel but the dentin as well. At some point, the pulp gets affected as well due to the central location of the cracks.
Cracked teeth usually require treatment (such as root canal treatment). The decision to treat and restore teeth will depend on the diagnosis. About 20% of cracked teeth cases diagnosed as reversibly inflamed will need a dentist to perform root canal treatment within six months.
Craze lines are typically not a sign of dental health issues like tooth decay or weak teeth. They also usually don’t predispose your teeth to cracks or cause or worsen cracked teeth.
No, craze lines don’t weaken your teeth. They are just harmless, cosmetic issues that don’t impact your oral health standing.
Craze lines also don’t indicate cracked teeth, nor do they lead to cracks.
Here are things you can do to prevent craze lines and to reduce their visibility:
If you have craze lines, your general dentist might recommend that you get porcelain veneers, as you might be unable to remove craze lines even after treatment. Porcelain veneers, also called dental veneers, are thin, custom-made shells of tooth-like materials made to cover the external surface of teeth so as to improve their appearance.
Some other things that you can do to fix your teeth craze lines include:
Craze lines can cause tooth discoloration, which can affect people’s self-esteem. However, with certain dental care procedures, you can remove tooth stains.
Some ways you can whiten teeth with craze lines include:
Craze lines tend to cause tooth sensitivity after whitening using the oxygenating chemical- hydrogen peroxide.
- Bleaching Induced Tooth Sensitivity: Do The Existing Enamel Craze Lines Increase Sensitivity? A Clinical Study
Dabuleanu, Mary, and Alexander Suham. “How Does One Decide Whether A Crack/Craze Line on An Asymptomatic Tooth Should Be Attempted To Be Removed, Either With A Restoration Or A Crown?” Canadian Dental Association, 5 June 2014, http://oasisdiscussions.ca/2014/06/05/ct/
Krell, Keith V, and Eric M Rivera. “A Six Year Evaluation of Cracked Teeth Diagnosed With Reversible Pulpitis: Treatment and Prognosis.” Journal of Endodontics, vol. 33, 12 (2007): 1405-7. Doi: 10.1016/j.joen.007.08.015, https://pubmed.ncbi.nlm.nih.gov/18037046/
Mariona, Preethi, and Anthony Delphine. “Diagnostic Methods for Cracked Tooth by Two Endodontic Tools.” Drug Invention Today, vol 10, 2 (2018): 0975-7619, https://jprsolutions.info/files/ms-file-5bd016fe9c0e54.82726411.pdf
Mutlu, Ozcan et al. “Bleaching Induced Tooth Sensitivity: Do the Existing Enamel Craze Lines Increase Sensitivity? A Clinical Study.” Odontology/ the Society of the Nippon Dental University, vol 102, 2 (2014): 197-202. https://www.researchgate.net/publication/235906209_Bleaching_induced_tooth_sensitivity_Do_the_existing_enamel_craze_lines_increase_sensitivity_A_clinical_study
“What are Craze Lines?” Dawson Dental. https://dawsondental.ca/what-are-craze-lines/#
Yahyazadefar, Mobin et al. “On the Importance of Aging to the Crack Growth Resistance of Human Enamel.” Acta Biomaterialia, vol. 32 (2016): 264-274. Doi: 10.1016/j.actbio.2015.12.038, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4754146/