The Oral-B Sensitive Gum Care electric toothbrush replacement head features extra soft bristles for a superior* gentle clean, ideal for cleaning around sensitive and inflamed areas. The round brush head is inspired by dental professional tools for a tooth-by-tooth clean, with specially engineered bristles for optimal tooth coverage. Indicator bristles signal time to replace brush head. Dentists recommend changing your brush head every 3 months. *vs. a regular manual toothbrush.