Teeth are an important part of physical appearance for many people, and therefore they want to display a bright white smile. However, a new study reveals that many teeth whitening products can do just the opposite: damage teeth.
Previous studies have shown that most human teeth are not naturally pearl white. Actually, most teeth have different shades that tend towards yellow – not nuclear white. Also, the teeth are not uniform in color either.
Despite this, there is an idea, especially prominent in American societies, that incredibly white teeth are a symbol of beauty and personal care. A concept that is also catching on in Europe. For this reason, many people choose to whiten their teeth, either on their own or with the help of a cosmetic dentist.
Now, several studies show that teeth whitening with whitening products that contain hydrogen peroxide can endanger the health of the teeth.
How does hydrogen peroxide damage teeth and what part of the tooth does it attack?
The research, led by Kelly Keenan from the University of Stockton (USA), was presented at the 2019 Experimental Biology meeting, which is part of the annual meeting of the American Society for Biochemistry and Molecular Biology in Orlando, Florida and gave precisely an answer to this question.
After their study, the experts observed that the whitening strips, which everyone can buy without a prescription, damage one of the three sensitive layers of the teeth .
Teeth whitening strips generally contain hydrogen peroxide as the main active ingredient. This substance is an oxidizing agent that some people use in a sterilizer, although most know it as an agent used to lighten the color. It is precisely the main substance that is used to bleach hair. It is known that if you use too much or too much of this substance to lighten hair color, it can cause “significant damage” to the hair and scalp.
Damage to dentin
Now Keenan and his team have discovered how hydrogen peroxide damages dentin, the “middle” layer of teeth. A tooth contains three different layers: an outer layer of shiny enamel, a layer of dentin in the middle, and an inner layer that is primarily connective tissue, which helps hold the tooth in place.
Hydrogen peroxide, Keenan explains, can pierce enamel and infiltrate dentin, which contains about 90 to 95% of the protein of collagen.
In this study, “we tried to better characterize what hydrogen peroxide was doing to collagen,” says Keenan. “We used whole teeth for the studies and we focused on the impact that hydrogen peroxide has on proteins,” he adds.
The researchers found that collagen present in dentin breaks down when exposed to hydrogen peroxide, leading to loss of collagen mass in that layer.
“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 likely due to the formation of many smaller fragments.” Keenan concludes.
Experts are still not sure if this damage is permanent or if there is any way to reverse it. In the future, they plan to find out if hydrogen peroxide affects not only collagen, but also other proteins that dentin contains.
Referencia: Experimental Biology 2019 meeting. American Society for Biochemistry and Molecular Biology
