Its very important to understand that your teeth are dehydrated from the whitening treatment and this is what causes tooth sensitivity. Now keep in mind that your own saliva will naturally rehydrate your teeth within an hour or so after the treatment, therefore the sensitivity will go away by itself.
After your treatment, we also send you home with our home kit which includes our remineralisation gel. Our remineralisation gel works very similar to Sensodyne (a toothpaste that helps reduce tooth sensitivity for people with sensitive teeth) in the sense that it greatly reduces tooth sensitivity by hydrating the enamel and coating it with a calcium phosphate protective layer. So, if you do experience sensitivity after the treatment just use the remineralisation gel to relieve any sensitivity you may be experiencing.