From here: http://www.hon.ch/News/HSN/511232.html
Study: Most Electric Toothbrushes No Better than Manual Ones
About 55 million Americans use electric toothbrushes, but a new study finds that only one type works better than the old-fashioned, manual ones.
The Washington Post reports that electric toothbrushes with bristles that spin in both directions are the only ones that offer an advantage over the manual type. An example of that type is the Braun Oral-B device, made by Gillette Co. The company says Oral-B is used by 41 percent of electric toothbrush users.
The report was conducted by the Cochrane Collaboration of Oxford, England, which periodically issues studies on medical devices whose worth hasn’t been proven.
Other models studied included the Philips Sonicare, the Interplak, the Teledyne Aqua Tech, the Ultrasonex, the Rowenta Dentiphant and the Rowenta Plaque Dentacontrol Plus, the Post reported. They were “not worse, but they were just not any better” than manual brushes, said William Shaw, a professor of orthodontics at the University of Manchester who led the study.