Gum massaging bristles. The unique curved bristle-bed ensures our plush bristles clean and massage the gum rather than aggravating them. Choose your bristle type! Our Super Soft Flossing bristles are tapered to get closer to your gum line while our Soft and Medium bristles are end-rounded for a pillow-soft clean. Pair these replacement heads with our Big Brush™, Source™ Brush, or TOUR™ Travel Brush. Premium, eco-friendly bristles. The soft bristles are made from vegetable-based nylon to reduce our dependence on fossil fuels. The bristles are arranged in an elegant fanned shape, designed to gently yet thoroughly clean and invigorate the entire mouth.