Clinically proven: Removes plaque 10x better than the brush heads of the best-selling private label in Germany (12-week average plaque removal, Nielsen Trade Panel L12M). The original brush heads from Oral-B were designed with X-shaped bristles that clean areas that regular bristles cannot reach. The green indicator bristles turn yellow over time depending on individual usage, indicating the optimal time to replace the brush head - for 100% cleaning power.