Most people dream of a bright smile and white teeth. Unfortunately, most of the current whitening methods are far from harmless for our quenottes. Most use gels based on peroxidehydrogen (oxygenated water), sometimes activated with a lamp infrared. A compound that can damage theE-mail, cause a tooth sensitivity or irritation of the gums. In addition, this method involves many weeks of treatment and is not always effective. A team of Chinese scientists therefore sought to develop a teeth whitening treatment without all these harmful side effects.
Xingyu Hu and his colleagues have developed a catalyst which, under the effect of light infrared, improves the effectiveness of hydrogen peroxide at tooth-friendly concentrations. Their gel incorporates nanoparticles of titanium dioxide (TiO2) oxygen deficient which catalyzes the production of hydroxide radicals from hydrogen peroxide. These hydroxyl radicals are particularly effective in breaking down pigments in stains. By exposing the nanoparticles to infrared light, the researchers managed to completely whiten tooth samples stained with orange and red dye, and tea in less than 2 hours. They then made a gel containing these nanoparticles with a concentration of 12% hydrogen peroxide. They found that its effectiveness was similar to that of a popular whitening gel containing 40% hydrogen peroxide, while causing less damage to the enamel.
However, it should be noted that European regulations limits the concentration of hydrogen peroxide to 6%, including in dental offices. It will therefore be necessary to further improve the efficiency of the catalyst to make this gel marketable here.