The history of manual toothbrushes dates back to the Tang Dynasty in China. Credit: Valentyna Yeltsova/Getty
Researchers at Peking University in Beijing have developed a battery-free toothbrush that generates its own electrical charge while brushing to destroy bacteria, rather than relying only on mechanical friction. The team reported that the brush did not damage tooth surfaces or show toxicity to human cells, although its long-term safety, cost and effectiveness still require further study. The work was published in Scientific Progress on November 41.
Frank Scannapieco, a periodontist and microbiologist at the University at Buffalo in New York, described the approach as “a new twist on an old concept.” Generating electricity through toothbrushing could potentially reduce plaque more effectively, he said, but additional trials are needed to establish whether the brush is effective and safe.
Suppressing bacteria with electricity
Manual toothbrushes with bristles have been used since the 10th century AD. They primarily rely on movement to remove plaque, the film of saliva around the teeth in which bacteria grow.
The researchers made the brush’s bristles from polyvinylidene fluoride, a polymer that can generate an electrical charge when deformed. They stretched and heated the material into curved, piezoelectric shapes.
As the brush is used, the curved bristles release an electrical charge that generates highly reactive oxygen in the surrounding saliva. According to the researchers, these reactive compounds damage bacterial cell membranes. When the bristles relax, the material absorbs the charge again.
Source: www.nature.com
