Oral-B Cross Action Indicator has perfectly angled bristles to remove up to 90% plaque in hard to reach areas. It's new bristle technology signals when to change for your best clean. CrissCross bristles flex and straighten to penetrate hard-to-reach plaque in-between teeth New bristle technology that turns green bristles to yellow, signaling when it's time to change Power Tip bristles help reach deep and clean hard-to-reach areas while still being gentle enough on your enamel Soft gum stimulators positioned on both sides of brush head gently massage the gums.