The plaque removing capability of rotary electric toothbrushes relies on the scrubbing motion of the brush's bristles on a tooth's surface. What is different from previous generations of electric toothbrushes are rotary toothbrushes often possess some ability to reach between the teeth or below the gum line to some degree. Studies have shown that rotary electric toothbrushes are superb in regards to plaque removal and reduction in gingivitis. These findings can most likely be attributed to both the enhanced cleaning action of the bristle movements of these brushes.