Forget strips, gels, and pastes. Your next tooth-whitening and repairing substance might well be a new powder developed by Shanghai researchers. You'll want to use it with an electric toothbrush though, because that's what makes it spark.
The earliest recorded use of dental powders come from the Egyptians around 5,000 BCE when abrasive ingredients like ox-hoof ashes and burned eggshells were used to scrub teeth. But now, a team of Chinese researchers has just planted the humble tooth powder firmly in the 21st century with a formulation that gains an electric charge after being activated by the vibrations from a motorized toothbrush.
The powder (named BSCT based on its molecular makeup) works off the principle of piezoelectricity, the electric charge that accumulates in certain solid materials when they are put under some kind of physical stress. In this case, the solid materials are ceramic particles consisting of strontium and calcium ions combined with barium titanate. And the physical stress is the vibration caused by the spinning heads on electric toothbrushes.
When those particles were vibrated by brushing, they gave off a small electric field. This, in turn, created chemical reactions that generated reactive oxygen species (ROS) – oxygen-containing molecules, such as hydrogen peroxide, that readily react with other substances thanks to unstable electrons. ROS are typically used in whitening products on the markets such as strips and gels because they are effective in blasting apart stain-causing molecules. Sometimes, however, the ROS compounds can also damage tooth enamel.
In testing on human teeth that were artificially stained with tea and coffee, the researchers found that a total of four hours of brushing showed visible whitening, while 12 total hours of brushing led to teeth that were nearly 50% whiter than those in a control group. More significantly though, instead of damaging teeth, the team found that brushing with BSCT helped restore teeth with damaged enamel and dentin because the calcium and barium ions built up on the tooth surfaces.
Testing the powder on rats fed a high-sugar diet, the team found that brushing with BSCT for just one minute a day was enough to restore the rats' oral microbiome, reduce inflammation, and kill the bacteria that causes periodontitis.
The powder has yet to be formulated into a commercial toothpaste, but the study shows a way forward to use a very old-fashioned tooth treatment in a very modern way.
"This work offers a safe, at-home teeth whitening strategy integrating whitening, enamel repair and microbiome balance for long-term oral health," concludes first study author Min Xing, from the Laboratory of Dental Biomaterials and Tissue Regeneration at the Shanghai Xuhui District Stomatological Hospital.
The study has been published in the journal ACS Nano.
Source: American Chemical Society
