The Sensitive Clean brush head features ultra-soft bristles that are particularly gentle on the gums. It removes up to 100% more plaque and reduces gum inflammation by up to 100% vs. a manual toothbrush. The original Oral-B brush heads have been developed with new X-shaped bristles that now clean areas that normal bristles cannot reach. Dentists recommend changing the brush head every 3 months - for 100% cleaning power. Guaranteed fit with all Oral-B rechargeable toothbrushes except Pulsonic and iO.