The Oral-B Pro CrossAction brush head features more than 2200 perfectly angled bristles that remove up to 100% more bacterial plaque than a manual toothbrush – for cleaner teeth and healthier gums. The original Oral-B brush heads are designed with X-shaped bristles that also clean areas that regular bristles cannot reach. The green indicator bristles gradually turn yellow depending on individual usage, indicating the optimal time to replace the brush head – for 100% cleaning power.