Can docs explain what does sensodyne do for the teeth?

Potassium nitrite: The dentine is composed of many tiny tubules that are fluid filled and contain nerve endings. This fluid moves when the tooth is exposed to cold or hot temperature changes and this causes the nerve to fire causing the pain. Sensodyne has potassium nitrite that will prevent the nerve from firing so you do not feel pain. This process to stop nerve sensitivity can take a couple of weeks.