Unlike typical toothbrushes that only clean one surface at a time, this advanced model has four heads that clean six surfaces–the front, back, and chewing surface of top and bottom teeth–simultaneously. The electric toothbrush automatically executes the Bass technique, a brushing method recommended by the American Dental Association: the bristles are aligned at a 4° angle and move towards and away from the gums 810 times per minute to remove bacterial plaque from teeth and at or below the gumline.