GALLOWAY, N.J. — Having the perfect smile may be priceless to some people, but if you’re using whitening strips to brighten your pearly-whites, you could actually be doing more harm to your teeth than good, a new study finds.
Researchers at Stockton University say that hydrogen peroxide, the active ingredient in many popular whitening products, can damage teeth by weakening the bone-like tissue beneath the tooth’s outer layer of protective enamel. This tissue, known as dentin, makes up the bulk of each tooth and contains high levels of protein, which is almost entirely collagen.
Previous studies had shown that whitening strips caused collagen within dentin to decrease. For this work, the authors conducted three different studies to better understand why this occurred and how whitening strips are able to affect the proteins within the layers of the teeth.
In one study, they treated teeth with over-the-counter strips for two weeks, using one or three rounds on teeth in an artificial saliva solution. “The results show a loss of protein with a decrease in size when the proteins were treated with [hydrogen peroxide],” the authors wrote. “These results suggest that if the active ingredient in whitening treatments can penetrate the enamel, it can damage the non-collagen proteins in the teeth.”
Researchers exposed albumin protein, which is the main protein of blood plasma, to different levels of hydrogen peroxide in the second study. In this experiment, they found that the protein was more susceptible to hydrolysis, or the chemical breakdown of a compound within water, when exposed to levels of hydrogen peroxide found in the strips.
In the third study, the authors treated pure collagen with with either hydrogen peroxide or water for an hour. They found the damage to collagen was especially concerning, occurring within just 10 minutes of exposure to the chemical compound.
“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,” says co-author Kelly Keenan, an associate professor of chemistry at the university, in a release.
Keenan notes that it’s possible the damage may not be permanent, as the authors did not study whether or not the damaged proteins could be regenerated within teeth. In future work, the team will determine how the strips may affect other proteins found in teeth.
The study’s results were presented at the American Society for Biochemistry and Molecular Biology annual meeting in Orlando, Florida.