The bristles are made of CUREN and, even when they are wet, they retain their superior original firmness. This allows the use of much finer filaments for gentle, deep brushing. With its small, compact head, the CURAPROX Sensitive cleans more intensively and more gently. When you brush with the CURAPROX CS, your tongue will notice the difference at once: your teeth will feel smooth and clean and naturally appear whiter.