See: Are dentists hooking patients on opioids? “Still, it’s good to always keep an eye out on what the research is showing about products that we commonly use.” “Those teeth were probably dehydrated and had a different composition than the teeth that are in a living person,” author and orthodontist Dr. There are some limitations this was not a peer-reviewed study, and living teeth in a person’s mouth will react differently to whitening agents than extracted teeth.

“Our results show that treatment with hydrogen peroxide concentrations similar to those found in whitening strips is enough to make the original collagen protein disappear,” said Keenan in a statement. And those whitened three times had even smaller amounts of collagen. They found that the teeth whitened with strips once had less collagen and other proteins than the untreated teeth the proteins were converted to smaller fragments. Then they tracked the level of collagen and other proteins remaining in the dentin layer of the whitened teeth, and compared that to a control group of unbleached teeth, as well as to another set of teeth that were whitened three times. Researchers also immersed the teeth in artificial saliva and washed them, to simulate what teeth experience in a human mouth. The study, led by Kelly Keenan, an associate professor of chemistry at Stockton University, treated extracted human teeth (from cadavers) with whitening strips, following the manufacturer instructions to leave them on for an hour.

And this latest research found that the hydrogen peroxide that serves as the active ingredient in whitening products could be hurting that protein-rich dentin layer. Our teeth are made of three layers: the outer white enamel layer the underlying dentin layer composed of proteins (namely collagen) and the pulp in the center that houses nerves, blood vessels and connective that binds the tooth to our gums.

Patchy teeth after zoom whitening