The Dual Clean replacement toothbrush head has two moving brush heads for a comprehensive clean. One bristle section moves side to side while the other oscillates and pulsates for twice the cleaning action. It can even penetrate hard-to-reach areas. Try the Dual Clean and discover a thorough, whole-mouth clean, and feel fresher. The Dual Clean toothbrush head features twice the cleaning action, thanks to two moving brush heads in one. It delivers a thorough cleaning to remove plaque, freshen and provide gum care. The Dual Clean works with unique Oral-B technology that oscillates, rotates and pulsates, allowing the bristles to surround each tooth for an amazing, tooth-by-tooth clean. Dentists recommend replacing your brush every 3-4 months. Oral-B brush head refills feature Indicator bristles that fade halfway to help remind you when to replace your toothbrush head so you maintain a superior clean.