(CNN) – Hydrogen peroxide, the active ingredient of over-the-counter bleaching strips, could harm the under-tooth enamel layer, according to a study presented Tuesday during the summer. a scientific meeting.
Teeth consist of three layers: the outer enamel, an underlying layer of dentin and the connective tissue that binds it to the gum. The intermediate layer, dentin, is rich in protein, the collagen of which is the most abundant.
Most studies on the safety of hydrogen peroxide have focused on enamel. The chemical is known to penetrate the enamel and reach the dentine, albeit in minute amounts, explained Dr. Edmond Hewlett, deputy dean of the UCLA School of Dentistry and spokesman for the ### 39; American Dental Association, which did not participate in the new study.
Kelly Keenan, lead author of the study and an associate professor of chemistry at Stockton University in New Jersey, said in a statement that she and her colleagues "were seeking to further describe what peroxide is. Hydrogen made collagen.
In the United States, all bleaching products contain hydrogen peroxide and / or carbamide peroxide, according to the American Dental Association.
Using whole teeth and artificial saliva, researchers found that dentin collagen breaks down into smaller proteins when treated with hydrogen peroxide, according to the results presented at the American Society meeting. biochemistry and molecular biology.
"Our results show that a treatment with hydrogen peroxide concentrations similar to those found in whitening strips is enough to remove the original collagen protein," Keenan said.
Hewlett warns against generalizing the results obtained with extracted teeth, as they might not represent the same environment as a person's mouth.
As the research is still in its infancy, it is not clear to what extent dentin is damaged, what it would mean to patients and whether the damage is permanent, he said.
"The teeth whitening products that are mentioned in the summaries have been around for decades and are used by millions and millions of people," he said. "With regard to the integrity of the damaged tooth, it has not emerged."
The most common adverse effect observed by dentists after the use of whitening strips is the sensitivity of the tooth, which is transient and does not represent an underlying lesion of the tooth, does it declared.
Hewlett recommends looking for products bearing the seal of acceptance of the American Dental Association, which means that they have been tested for their safety and effectiveness by the organization.