When the protective layer of teeth (enamel) is worn away or gums recede, the dentine underneath becomes exposed. When the exposed dentine comes in contact with hot, cold, sweet or sour food and drinks, it can trigger a sharp short sensation called tooth sensitivity. Sensodyne Rapid Relief is a daily fluoride toothpaste that acts rapidly against tooth sensitivity, while still providing the benefits of a regular paste like strong teeth and health gums. It starts to act rapidly by building a mineral-like layer over exposed dentine and within microscopic channels. The paste also builds ongoing protection with every brush so that you can enjoy your favorite foods and drinks without the worry of sensitive teeth. Sensodyne Rapid Relief tooth paste is available in two packs - 80 gm and 160 gm (80 gm * 2) combo pack. Brushing twice a day provides protection from tooth sensitivity. Always follow instructions and guidance included on the pack before use.