Product Information - Oral-B Interdental Brush Refills are designed for cleaning hard-to-reach interdental spaces. Brush angle is adjusted by moving the side of the handle, eliminating the need to touch the brush. - Cleaning Techniques; Position brush to desired angle by sliding the sides of brush handle. Insert brush between teeth. Using a soft back-and-forth motion, remove plaque and food particles. - Discard brush when bristles become worn.