The Cochrane Oral Health Care Group’s review (30 years of studies) compared manual and power toothbrushes and found that models with rotation-oscillation action (bristles that rotate in one direction, then the other) were the only ones superior to manual toothbrushes in reducing plaque and gingivitis—and the improvement was “modest.” No studies actually showed a reduction in periodontal disease or cavities even with rotation-oscillation action—all types of power toothbrushes worked well, but no better than manual. The Cochrane Collaboration assembles independent researchers to evaluate studies.
It’s fairly easy to maintain your dental health. A plain soft-bristled toothbrush is still your best buy. Use a fluoridated toothpaste, brush for two minutes each session, and replace the brush every three months or so. Floss at least once daily. See your dentist every six months for a professional checkup and cleaning.