Clinically confirmed: Removes plaque 10x better than best-selling private label brush heads in Germany (12 weeks average plaque removal, Nielsen Retail Panel L12M). The original Oral-B brush heads were developed with the X-shaped bristles, which now also clean the areas that normal bristles cannot reach. The green indicator bristles turn yellow over time depending on individual use, indicating the optimal time to change the attachment brush - for 100% cleaning power. Guaranteed fit with all Oral-B rechargeable toothbrushes, except Pulsonic and iO.