A study led by Canadian researchers highlights the extensive damage that can be caused by common tooth-whitening agents.
Published in Scientific Reports, the study by a team at the University of Toronto assessed the dental cell damage caused by the use of carbamide peroxide teeth-whitening treatments.
It found that a recommended application of just 10 per cent carbamide peroxide gel on teeth (35 per cent carbamide peroxide gel can be purchased online) reduces the enamel protein content by up to 50 per cent.
“We have always been interested in the effect of peroxide-based tooth whitening on the tooth structure and its link to sensitivity,” lead researcher A/Prof Laurent Bozec said.
“Here, we wanted to further understand the impact on the enamel itself and deep inside the pulp.”
A/Prof Bozec had been looking at the effect of using hydrogen peroxide in root canal treatment prior to this study and found that it was causing damage to collagen locally. This led him to investigate how peroxide penetrates through the enamel and dentine before reaching the dental pulp—and checking what damage it may cause along the way.
The study found that the loss of enamel protein content resulted in a greater penetration of the whitening agent inside the tooth, and can lead to an increase in dental pulp cell mortality.
The team used an in-house dentine perfusion chamber to make their measurements. At carbamide peroxide concentrations around 35 per cent, the researchers found that dental pulp cells did not survive the exposure.
“Many home tooth-whitening products have such a high concentration of peroxide gel—for example, 35 per cent—and yet, little is known about what it does to the inside of our teeth,” A/Prof Bozec said.
“We believe this is the first study of its kind to show the toxic effects of using a tooth-whitening agent. Our hope is that people will opt for a lower concentration of peroxide if they decide to use a tooth-whitening product as they are so much less harmful to your teeth.”