Daily repair toothpaste Why use Sensodyne Repair & Protect Whitening? It is possible to treat the pain of sensitive teeth and to repair these vulnerable areas. With twice daily use, new Sensodyne Repair & Protect Whitening continuously repairs strengthens and protects your teeth, whilst restoring them to their natural whiteness. What is tooth sensitivity? Sensitivity occurs when the dentine underneath tooth enamel becomes exposed. When exposed dentine comes into contact with hot or cold, sweet, sour or even your toothbrush it can trigger the nerve, causing a short sharp pain.