Innovative technology delivers better results. Now there's a guaranteed way to better oral health. It's the new Philips Sonicare FlexCare that adapts to your oral care needs. The contoured brush head fits along the gum line to gently clean and massage gums. Align the brush head so the bristles face the front of the handle and firmly press the brush head down on the metal shaft until it stops. Reminder bristles let you know when to replace the brush head. After three months of normal use bristles exhibit fatigue, and brush heads are less effective. Replace your brush head every 3 months.