The iO 3 electric toothbrush is equipped with Oral-B's good technology and combines a dentist-inspired round brush head with micro-vibrating bristles for a professional, clean feeling at home. The intelligent pressure control prevents brushing too hard or too gently to better protect the gums. The Gum Guard warns you if you brush your teeth for too long with too much pressure. Replace the brush on your Oral-B iO toothbrush every 3 months to achieve optimum results.