What is tooth sensitivity? Tooth sensitivity is a very common condition. It occurs when tooth enamel is eroded through daily eating or when the gums are exposed to heat and cold, causing pain. At that time, hot and cold stimuli affect the nerves inside the tooth, causing pain. How does Sensodyne help? Sensodyne is an expert for sensitive teeth. When used twice daily, the three cleansing actions of Sensodyne effectively prevent bacteria, remove plaque, brighten teeth, and help maintain strong teeth and healthy gums.