A light-powered toothbrush?

Would you like to use a light-powered toothbrush which needs no toothpaste and no batteries? It’s already available in Japan and North America and it costs about $30. Its rod contains titanium dioxide that generates a plaque-removing electrochemical reaction. This ’solar’ toothbrush of the future ‘works by releasing electrons that then react with the saliva in the mouth and help to breakdown plaque.’ It just needs some light — so you’ll be able to wash your teeth in your garden or on your balcony. And as it has no batteries, this is a very eco-friendly device. It is currently tested today by 120 students at the University of Saskatchewan, Canada, but it’s already available online.

You can see above how the light-powered Soladey toothbrush works. (Credit: Soladey-USA, on this page Here is a link to an ebven better graphical explanation from the New York Times. And you also might want to look at this short TV Commercial about this toothbrush.

Here are some more details provided by the Cosmetics Design Europe article. “The toothbrush is powered by light. When light hits the solar panel in the handle of the toothbrush electrons are released and delivered to the semiconductor head (titanium dioxide), explains the manufacturer. In addition, when light strikes the wet titanium dioxide head more electrons are released, which form a negatively charged fluid inside the mouth that can remove hydrogen ions from the plaque making it easier to break down, says the manufacturer. The toothbrush, therefore, cannot work in the dark. However, it takes the same amount of light as a solar-powered calculator, so that if the user can see their reflection in the mirror there is enough light to operate the brush.”

In “New brush could make toothpaste obsolete“, Janet French from CanWest News Service added that “University of Saskatchewan dentistry professor emeritus Dr. Kunio Komiyama and his colleague Dr. Gerry Uswak are recruiting 120 teens willing to brush with a prototype light-powered toothbrush and sit in a dentist’s chair for a few extra inspections.” So far Komiyama saw a complete destruction of bacterial cells.

And in “Brushing Innovations, Built on Titanium,” Joyce Cohen, from the New York Times, provides additional technical details. “The brush, available at soladey-usa.com, relies on a property of titanium dioxide. It is photocatalytic, meaning that it causes chemical reactions in the presence of light. Light shining on the titanium dioxide rod in the brush’s handle generates negatively charged electrons, which steal positively charged ions from dental plaque, causing oxidation. Brushing creates a slurry of negatively charged saliva, which attracts and decomposes plaque.”

According to the New york Times, Donald C. Selmarten, a senior scientist at the National Renewable Energy Laboratory in Golden, Colorado, thinks that the concept makes sense, but “has questions about the details — whether the wavelength of visible light is high enough to drive the reaction inside a dark mouth, and whether the resulting positive charge will actually remove plaque.”

This toothbrush is manufactured by Shiken Corporation of Osaka, Japan (page in Japanese) and available in North America from Soladey USA. And here are two questions you might ask about this toothbrush which are already answered in the Soladey FAQ section.Here is one: “Can Soladey be used with or without toothpaste? Yes, the ionic power of Soladey works with or without toothpaste. If you do want to use toothpaste, just make sure it doesn’t go all down the handle, blocking the light from getting to the light-sensitive rod. A strong light source is what makes Soladey most effective. If you wish to freshen your mouth we recommend using a natural mint rinse after brushing.”

But here is my preferred one. “Will any light source do? I’m not going to have to go outside to clean my teeth, am I? No, any light source will work, a fluorescent bathroom light, or a plain light bulb will do fine. Any natural or artificial light is all that’s needed. However, the better the light source is, and the more the titanium rod is in the light, the more effective Soladey is. Perfect your brushing habits by keeping the Titanium Rod in bright light as much as possible.’

Sources: Katie Bird, Cosmetics Design Europe, November 23, 2007; and various websites
Extracted from ZDnet blog