People who assume that tooth whitening is a product of the 21st century may be surprised to learn they are sorely mistaken.
In an article for the Providence Journal, Lisa Vernon-Sparks explained that people have been trying to get their smiles brighter ever since Ancient Egyptian times.
Indeed, 4,000 years ago, white teeth were seen as a status symbol just like they are now, she said.
However, people back then used ground pumice stone and vinegar to bleach their teeth.
Moving forward to the Roman times, Ms Vernon-Sparks said things had not got any better.
"Ancient Romans whitened their teeth using urine (you read that correctly). The ammonia in the urine was the bleaching agent," she commented.
Luckily, after a brief period of filing the teeth down in the 17th century, dentists began to learn more about safe teeth whitening, resulting in the vast knowledge available to us now.
Last month, American dentist Dr Kevin Sands said he is pleased cosmetic dentistry has come on leaps and bounds, as he can do so much more for his patients.
