Tracks wear on bristles. The brand more dentist use themselves worldwide. Indicator Bristles: Blue indicator bristles fade halfway so you know when to replace your brush. Comfort Fit Bristles: Comfortably curved for grooves between your teeth. Gentle End Rounded Bristles: Specifically designed to be gentle on teeth and gums. ADA Accepted: American Dental Association. The ADA Council on scientific affairs Acceptance of Oral-B Indicator is based on its finding that the product is effected for removing plaque and helping to prevent and reduce gingivitis, when used as directed. For more oral care information, visit www.OralB.com or call 1-800-56-OralB (1-800-566-7252). www.pg.com. Made in the USA (with US and imported parts).