The first successful electric toothbrush, the Broxodent, was conceived in Switzerland in 1954 by Dr. Philippe-Guy Woog. Woog's electric toothbrushes were originally manufactured in Switzerland (later in France) for Broxo S.A. The first clinical study showing its superiority over manual brushing was published by Pr. Arthur Jean Held in Geneva in 1956. Electric toothbrushes were initially created for patients with limited motor skills, as well as orthodontic patients (such as those with braces). Claims have been made that electric toothbrushes are more effective than manual ones as they are less dependent upon patients brushing correctly.

Independent research finds that most electric toothbrushes are no more effective than manual brushes (Robinson PG, Deacon SA, Deery C, Heanue M, Walmsley AD, Worthington HV, Glenny AM, Shaw WC (2009). Of course the comparison assumes that people using a manual toothbrush will brush properly. The "rotation-oscillation"-models, including many of the electrical brushes in Braun's Oral B-series, are marginally better than manual ones. The research indicates that the way brushing is done is more important than the choice of brush. For certain patients with limited manual dexterity or where difficulty exists in reaching rear teeth, however, dentists strongly feel that electric toothbrushes can be especially beneficial.

See also: https://en.wikipedia.org/wiki/Electric_toothbrush

Source: Wikipedia (All text is available under the terms of the GNU Free Documentation License and Creative Commons Attribution-ShareAlike License.)