Solar toothbrush zaps your oral bacteria without using toothpaste.

A variety of oral hygiene measures have been used since before recorded history. This has been verified by various excavations done all over the world, in which chew sticks, tree twigs, bird feathers, animal bones and porcupine quills were recovered. The first toothbrush recorded in history was made in 3000 B.C., a twig with a frayed end called a chew stick.

Many people have used some form of toothbrushes through the ages. Indian medicine (Ayurveda) has used the twigs of the neem or banyan tree to make toothbrushes and other oral-hygiene-related products for millennia. The end of a neem twig is chewed until it is soft and splayed, and it is then used to brush the teeth. In the Muslim world chewing miswak, or siwak the roots or twigs of the Arak tree (Salvadora Persica), which have antiseptic properties, is common practice. The usage of miswak dates back at least to the time of the Prophet Mohamed, who pioneered its use. Rubbing baking Soda or chalk against the teeth has also been common practice in history. - courtesy WIKI

Brushing your teeth is a regular ritual for most people, and normally that involves both a toothbrush and toothpaste to remove the gunk that builds up on our teeth and gums. The solar toothbrush looks to eliminate the paste, harnessing the power of the sun to kill off all that nasty bacteria.
The Shiken Soladey-J3X had a small solar panel near its base, which creates a stream of electrons that are emitted the head and react with acid in your mouth. Developers Dr. Kunio Komiyama and Dr. Gerry Uswak say that this results in "complete destruction of bacterial cells."
There is an opinion that bacteria aren’t the only thing brushing takes care of. Most toothpaste includes fluoride to fight cavities, and compounds to help remove any plaque deposits. If you get rid of the paste, will these problems become worse?