A team of researchers from China’s Nanchang University have developed a hydrogel coating that promises to whiten teeth and destroy cavity-causing biofilms.

The new hydrogel coating is the combination of bismuth oxychloride nanoparticles, copper oxide nanoparticles and sodium alginate, which when combined is activated by safer green light — a light wavelength on the visible light spectrum — instead of the often used blue light for teeth whitening applications.

Once the coating ingredients were combined and applied to teeth on slides in the lab, the researchers sprayed the mixture with a calcium chloride solution, which formed a strong adhering hydrogel.

Applied to teeth stained with blueberry sauce, coffee, tea, juice and soy sauce, and exposed to green light, the treated teeth got lighter without damaging enamel, the researchers reported. Additionally, the coating killed 94% of bacteria in the biofilms that formed on the teeth. The researchers also successfully demonstrated that the coating could work in vivo by applying the hydrogel to mice teeth in the lab.

This material, according to the researchers, promises a tooth whitening alternative to commonly used teeth whitening and anti-cavity solutions composed of hydrogen peroxide-containing gels currently in use that tend to break down enamel and blue light, which can damage skin and eyes.

The article, Fast cross-linked hydrogel as a green light-activated photocatalyst for localized biofilm disruption and brush-free tooth whitening, appears in the journal ACS Applied Materials & Interfaces.

For more on the hydrogel coating, watch the accompanying video that appears courtesy of the American Chemical Society.

To contact the author of this article, email mdonlon@globalspec.com