Oral-B Floss Action brush head features MicroPulse bristles that help provide a superior deep clean between teeth*. The bristles on the round brush head are designed to clean deep between teeth to remove up to 100% more plaque leaving your whole mouth cleaner than a regular manual toothbrush. The brush head is also equipped with colour-changing bristles that help you change your brush on time. The bristles turn from green to yellow, indicating when it is time to change.