Ultimate Clean brush heads are designed to optimize your iO brushing experience, giving you the feeling of a professional clean every day. 16-degree angled crisscross bristles remove more plaque for ultimate cleaning (*vs. manual toothbrush). Inspired by professional dental care products to clean hard-to-reach areas. Dentists recommend replacing your brush head every 3 months to maintain effectiveness. A worn brush head makes cleaning even more difficult, trapping millions of plaque-causing bacteria. Compatible only with Oral-b iO™ toothbrush.