Volume 9 • 2022 • Issue 5

A 2021 study 1 found that an application of 5% carbamide peroxide gel on teeth reduced the enamel protein content up to 50%. That loss of protein in the enamel resulted in a greater penetration of the whitening agent inside the tooth, which can lead to an increase in dental pulp cell death. Tooth Whitening Products May Damage Dental Cells D r. Laurent Bozec, an associate professor in the faculty of dentistry at the University of Toronto, previously studied the effect of hydrogen peroxide in root canal treatment and found that it caused damage to collagen inside the tooth. 2 This finding led to questions about how peroxide penetrates the enamel and dentine to reach the dental pulp, and what happens to living dental cells when peroxide reaches them. “We have always been interested in the ef fect of peroxide-based tooth whitening on the tooth structure and its link to sensitivity,” says Dr. Bozec. He is a biophysicist, who uses Atomic Force Microscopy technology to investigate collagen in tissues. “I come from a field where I look at the properties of tissues at a very small scale to understand how they function, ” he says. “My work with collagen brought me to dentistry.” His team at the U of T Bozec Lab used an in-house dentine perfusion chamber to make their measurements. At carbamide peroxide concentrations around 35% dental pulp cells did not survive the exposure. Dr. Laurent Bozec 27 Issue 5 | 2022 |