The shape of the head allows the bristles to surround each tooth for individual cleaning penetrates hard to reach areas indicator bristles fade as a sign to replace your toothbrush head for a better clean about every 3 months dentists recommend replacing your toothbrush head about every 3 4 months or when bristles are faded and worn compatible with the entire lineup of oral b rechargeable electric toothbrush handles except for oral b sonic toothbrushes oral b 1 brand used by dentists w