Teeth whitening is one of the most popular cosmetic dental treatments — and it's easy to see why. Having whiter teeth can make you look years younger, and the procedure itself is among the most conservative (and cost-effective) cosmetic treatments dentistry offers. Sometimes, however, achieving a pleasing, even shade of lightness can be challenging; this is particularly true when a tooth that needs to be lightened has been subjected to an injury (dental trauma) in the past.
Dental trauma encompasses any damage to the tooth that's caused by an external agent, whether accidental or intended. It may be due to a fall, a sports injury — or even a past orthodontic procedure. According to some studies, around a quarter of Americans aged 6 to 50 years old have experienced some traumatic dental injury, with most occurring before age 19. Traumatized teeth may react to whitening procedures differently from undamaged teeth, which can make them difficult to treat. However, several effective treatments are available.