Does Sensodyne toothpaste actually reduce sensitivity in one's teeth? If so, how?
The Sensodyne marketing includes an explanation, some of which includes a reference.
They claim that the products containing Potassium Nitrate work because the potassium stops the nerves from firing, citing Nagata, T. et al, Clinical evaluation of a potassium nitrate dentrific for the treatment of dentinal hypersensitivity, J Clin Periodontal. 1994;21:217-221.
They claim the products containing Strontium Chloride work by blocking the exposed tubules within the dentinal tissue, that stops fluid flow that triggers pain. They do not provide references on their web-site to support that claim.
Here are a couple of sources that might be helpful: This study addressed the "clinical effectiveness of strontium chloride" and found that out of a group of 132 patients, 72% had reduced discomfort and pain. No mechanism was offered.
This study seems to indicate that fluid flow is associated with dentinal pain (this addresses thermal stimulation)
This study indicates that potassium nitrate works through desensitization of nerve tissue within the tubules