Americans spend $1.4 billion every year on over-the-counter teeth whiteners, but research found that these products do more than bleach away stains of cigarettes and coffee.
According to researchers, whitening strips are eroding the underlying dentin layer beneath the enamel of the teeth. They discovered that hydrogen peroxide, a common active ingredient found in products, stripped away the collagen and other proteins of the teeth.
They presented their findings at the American Society for Biochemistry and Molecular Biology's Experimental Biology 2019 meeting this week in Florida.
Beyond The Surface
Previous research found evidence that over-the-counter whitening strips can damage the outer layer of the tooth: the enamel. However, hydrogen peroxide has been known to infiltrate the enamel and go deeper to the dentin, the layer that makes up most of the tooth. The dentin has significantly more protein, most of which is collagen, than the enamel.
To test how hydrogen peroxide affects the deeper layer of the tooth, the researchers treated extracted human teeth using over-the-counter whitening strips. The researchers also simulated a human mouth by submerging the extracted teeth into artificial saliva.
After an hour, the researchers tested the level of collagen and other proteins from the sample human teeth. They found that the teeth whitening products broke down major proteins in the dentin into smaller fragments.
"Our results showed that treatment with hydrogen peroxide concentrations similar to those found in whitening strips is enough to make the original collagen protein disappear, which is presumably due to the formation of many smaller fragments," explained Kelly Keenan, an associate professor of chemistry at Stockton University. She led the study.
Are Tooth Whiteners Bad?
However, James Sconzo, the chief of dental medicine at New York Presbyterian Brooklyn Methodist Hospital, is not too concerned. He said that he has not seen a higher rate of damage and decay among people who whiten their teeth.
The researchers also admitted that the study did not show whether the collagen in the tooth can regenerate after the treatment. They, therefore, cannot say as of now whether the damage caused by over-the-counter teeth whiteners are permanent.
The team hopes to continue studying the effects of hydrogen peroxide in collagen and other proteins found in the teeth.