New toothbrush generates electricity to combat bacteria

Researchers have incorporated polyvinylidene fluoride (PVDF) bristles into the brush, a material that produces electricity when flexed – a property known as piezoelectricity. This electrical charge triggers chemical reactions in saliva and water, releasing reactive oxygen species (ROS), which are molecules that can damage bacterial cells. The brush also maintains a surface charge even when not in use, hindering bacterial adhesion.

Oral microbiologist Nicholas Jakubovics of Newcastle University, who was not involved in the study, commented, “It’s great to have new approaches that actually enhance the effect of mechanical cleaning. The idea that the toothbrush surface itself is actively doing something is really interesting.”

Laboratory tests demonstrated the brush’s effectiveness, killing over half of the Streptococcus mutans bacteria – a key contributor to tooth decay – compared to just 9% killed by nylon bristles. It also reduced levels of Porphyromonas gingivalis, linked to gum disease, by up to 78%, significantly more than nylon brushes. The antibacterial effect diminished when an antioxidant was added, suggesting ROS are crucial to the brush’s function.

The research team observed changes in genes involved in bacterial nutrient transport after exposure to the electrified bristles. They hypothesize this disruption weakens bacteria, making it harder for them to survive and adhere to teeth. Biofilm tests on cow tooth enamel showed the brush removed over 99% of plaque, surpassing the performance of regular nylon brushes.

A three-month trial involving 115 adults with gum inflammation or tooth decay revealed that those using the electrified toothbrush experienced less plaque, reduced gum inflammation, and less bleeding compared to those using conventional brushes. Plaque samples also showed a decrease in harmful bacteria and an increase in beneficial bacteria.

While the team believes disease-linked bacteria have more fragile cell membranes, making them more susceptible to ROS, further investigation is needed to confirm this selectivity. Durability tests showed the PVDF bristles maintained their properties over three months of simulated use, and lab tests on mouse cells and cow tooth enamel showed no signs of damage. However, long-term human safety remains to be established. Jakubovics emphasized that larger studies are necessary to confirm the brush’s advantages over traditional methods, considering the current trial was relatively small and the bacteria were exposed to electricity for longer periods in the lab than during typical brushing.