In the past, Consumer Reports has said electric and manual
toothbrushes are equally effective as long as you brush teeth thoroughly for 2 minutes, twice a day. But an analysis of 56 studies published in 2014 by the international evidence-based research organization Cochrane found that electric models may have a slight edge.
Compared with manual toothbrushes, electrics reduced dental plaque 21 percent more and gingivitis (i.e., inflammation of the gums) 11 percent more after three months of use, the team from Cochrane found.
More than half of the studies Cochrane researchers looked at involved rotating, oscillating
electric toothbrushes featuring heads that spin swiftly in one direction and then the other. Other studies examined sonic toothbrushes that have vibrating brush heads; powered brushes that move side-to-side but don’t rotate; ones with tufts that move in different directions; as well as types that attempt to dislodge plaque via a mild electrical charge. The researchers didn’t draw conclusions about the best kind of brush.