Researchers at Peking University in Beijing have developed a battery-free toothbrush that generates its own electrical charge to destroy bacteria, supplementing the mechanical action of brushing. The researchers say the brush produces highly reactive oxygen in saliva that damages bacterial cell membranes, while early tests found no damage to tooth surfaces or toxicity to human cells. However, its long-term safety, cost and effectiveness still require further study.
The history of manual toothbrushes dates back to the Tang Dynasty in China. Credit: Valentyna Yeltsova/Getty
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 generating electricity while brushing teeth as “a new twist on an old concept.” He said the approach could reduce plaque more effectively, but added that further trials are needed to establish its effectiveness and safety.
Although the researchers found that the brush did not damage tooth surfaces and was not toxic to human cells, they did not assess its long-term safety or cost.
Bacteria suppression
Manual bristle toothbrushes, used since the 10th century AD, rely primarily on movement to remove plaque mechanically. Plaque is a film of saliva around the teeth in which bacteria grow.
The researchers made the brush’s bristles from polyvinylidene fluoride, a polymer that they stretched and heated into piezoelectric shapes. These materials generate an electric charge when they deform.
As the brush is used, its curved bristles release an electrical charge that creates highly reactive oxygen in the surrounding saliva. According to the researchers, these reactive compounds damage bacterial cell membranes. When the bristles relax, the material reabsorbs the charge.
Source: www.nature.com