White teeth are widely revered in many countries. Hollywood, advertising, and social media have helped to make ultra-white teeth a must-have, and even an obsession. For decades, people have used peroxide-based chemical whiteners in an attempt to get a perfect set of "pearly whites". However, these chemicals can damage the teeth and gums. Help is now at hand for those of us who have stained or off-white teeth. Researchers in China say they have created an effective teeth-whitening ceramic powder. Researcher Min Xing said it is "a safe, at-home teeth-whitening strategy integrating whitening, enamel repair, and microbiome balance for long-term oral health".

The researchers wrote about how their new powder works. It is activated by electric toothbrush vibrations, which create a small electric field over the teeth. This causes a reaction known as "reactive oxygen species". These are compounds that break down stain-causing molecules. The researchers said their laboratory trials were very promising. They tested human teeth that were artificially discoloured with tea and coffee. After four hours of brushing, there was visible whitening. After 12 hours of cleaning, the teeth were 50 per cent whiter than those brushed with saline. The researchers said the next step is to incorporate the powder into a toothpaste formula.