The replacement heads Oral-B iO Gentle Care are designed for gentle yet effective cleaning, making them ideal for people with sensitive teeth and gums. The heads have a round shape, inspired by dentists, and feature up to 4,000 soft bristles. These bristles protect the gums and adapt precisely to the curvature of the teeth to ensure no area is left uncleaned. The heads combine the bristles with the micro-vibrations of iO technology to remove up to 100% more plaque compared to a regular manual toothbrush.