The purpose of a toothbrush is to get rid of foreign particles from inside
the mouth. These particles of food and plaque are places where bacteria can
safely multiply, leading to bad breath tooth decay and gum disease.
There was some research from british universites in 2003 that seemed to show that electronic brushes were no better than manuals at producing cleaner teeth.
Only the rotation-oscillation brushes out-performed manual brushing in that experiment.
However for people like me who are not obsessive about brushing their teeth, theElectric toothbrushes seems to help us remember to go everywhere. Maybe it is the bussing or the smaller heads which remind me of the dentists chair and cause me to take longer using the electric toothbrush than I used to with my old hand held.
In addition we can think about people who have limited movement range, be it through arthritis or any other form of disability. The electric toothbrush requires less movement on behalf of the owner than a manual brush to achieve the same cleansing effect.
For these reasons I will continue to use my Philips Sonicare HX7351/02 Elite Electric Toothbrush.