A study by researchers in the US has found that hydrogen peroxide, the active ingredient in over-the-counter whitening strips, can damage protein-rich dentine tissue 

Researchers from Stockton University in New Jersey working under Kelly Keenan, PhD, associate professor of chemistry presented their findings at the recent American Society for Biochemistry and Molecular Biology annual meeting.

It is well established that hydrogen peroxide can penetrate the enamel and dentine.

Previous work by the researchers showed that collagen in the dentine layer decreased when teeth were treated with whitening strips.

‘We sought to further characterise what the hydrogen peroxide was doing to collagen,’ said Professor Keenan.

‘We used entire teeth for the studies and focused on the impact hydrogen peroxide has on the proteins.’

In their new work, the researchers demonstrated that the major protein in the dentine is converted to smaller fragments when treated with hydrogen peroxide.

In additional experiments, they treated pure collagen with hydrogen peroxide and then analysed the protein using a gel electrophoresis laboratory technique that allows the protein to be visualised.

‘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,’ she said.

The researchers point out that their experiments did not address whether collagen and other proteins in the teeth can be regenerated, so it is unknown if the tooth damage is permanent.

Next, they plan to further characterise the protein fragments released when collagen is treated with hydrogen peroxide and determine if hydrogen peroxide has the same impact on other proteins in the teeth.