The professionally-inspired round design of the toothbrush head of Oral-B Smart 4 4000 electric toothbrush surrounds and adapts to each tooth as it oscillates, rotates, and pulsates to break up and remove up to 100% more plaque than a regular manual toothbrush. Oral-B Smart 4 4000 electric toothbrush provides focused care and guidance along your dental care journey. Simply download the Oral-B App on your smartphone and connect with your brush for real-time feedback.