The Soladey-3 ionic toothbrush from Japan claims to get rid of plaque with electrons that work with saliva to remove plaque from your teeth.
A solar panel attached to the handle absorbs electrons from light and then transmits them to your teeth through ionised water and a titanium oxide semi-conductor in the handle.
The makers claim you don't need toothpaste as the electrons themselves do the job. However the British Dental Health Foundation has expressed its concern over the new invention and advises people to continue using toothpaste. Dr Nigel Carter, chief exec of the BDHF is calling for more tests to see if the brush actually does what is claimed, and to measure any long-term effects of not using toothpaste.
I checked the date on this report to make sure it wasn't April 1st.... but it wouldnt take off around here in 'sunny' Lancashire - there would only be enough solar power to clean people's teeth about 3 weeks of the year. Now develope a rain powered brush and you would be onto a winner.