Gently Power Away Gunk The round shape of the Oral-B Sensitive Clean® toothbrush head is awesomely designed to fit the mouths of tweens to gently power away gunk, resulting in an amazing, tooth-by-tooth clean. The soft bristles of the Sensitive Clean replacement toothbrush head are perfect for brushing away nasty plaque bacteria from teeth and gums, giving you and your tween something to smile about. Three of a Kind - Professionally Inspired Design Get more of a good thing – each Oral-B Sensitive Clean refill pack includes 3 toothbrush heads. In fact, each toothbrush head’s design is inspired by the round shape of professional dental cleaning tools and is perfectly sized for the mouth of your tween. The shape allows the bristles to surround each tooth for individual cleaning, resulting in an amazing, tooth-by-tooth clean. Know When to Restock Indicator™ Bristles fade halfway as a sign to replace your brush head for a better clean (about every 3 months).