The first thing people notice when they meet you is your smile. To be more confident when offering wide-mouthed, crinkled smiles, people want healthy, pearly-white teeth. But toothpastes only remove floor stains, and whitening treatments can damage enamel, leading to cavities and discoloration. Today, researchers at ACS Utilized Supplies & Interfaces report a new hydrogel treatment that breaks down cavity-forming biofilms and whitens teeth without damaging them.
According to the American Dental Affiliation, daily tooth brushing and flossing are good ways to to prevent the development of cavities. However, these methods do not effectively whiten teeth. For better whitening, consumers often turn to over-the-counter or professional treatments that combine gels containing hydrogen peroxide and blue light, producing a chemical reaction that removes stains. This combination removes most discoloration, but generates reactive oxygen species that can break down enamel. Previously, Xiaolei Wang, Lan Liao and their colleagues modified titanium dioxide nanoparticles for a less destructive teeth whitening treatment. This method still required high intensity blue light, which can damage nearby skin and eyes. So the team wanted to find a material that would be activated by green light – a safer option – to both whiten teeth and prevent cavities.
Researchers combined bismuth oxychloride nanoparticles, copper oxide nanoparticles and sodium alginate into a thick mixture. Then they evenly applied the mixture to the surface of the teeth bonded to a slide and sprayed the concoction with a solution of calcium chloride, forming a strongly adherent hydrogel. Next, the team tested the material on teeth stained with coffee, tea, blueberry juice and soy sauce and placed in a lab dish. After the treatment with the hydrogel and the green light, the teeth became brighter over time and the enamel was not damaged. In another series of experiments, the team showed that the treatment killed 94% of the bacteria in the biofilms. To demonstrate that the treatment could work on teeth in vivo, the team used the new method on mice whose mouths were inoculated with cavity-forming bacteria. The green light-activated hydrogel effectively prevented the development of moderate and deep caries on the surface of the animals’ teeth. Researchers say their safe, brushless treatment effectively prevents cavities and whitens teeth.
The authors acknowledge funding from the Countrywide Natural Science Foundation of China, from the Crucial Youth Venture of Jiangxi Province, the Key Investigation and Improvement Plan of Jiangxi Province, the Pure Science Basis of Jiangxi Province and the Graduate Innovation Special Fund Job of Jiangxi Province.
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