Indicator bristles. Comfort grip. The brand more dentists use themselves. At Oral-B we care for your oral health by developing innovative products that are trusted by dental professionals worldwide. Ergonomically designed handle for comfort and control. Indicator Bristles: Blue Indicator bristles fade halfway so you know when to replace your brush. Dentists recommend changing your brush every 3 months. Clinical research proves that a new toothbrush can remove 30% more plaque than one 3 months old (J Clin Dent 2002; 13:119-124). End-Rounded Bristles: Carefully polished end-rounded bristles are gentle on your teeth and gums.