Just sharing my thoughts here.
I used to work part time in a dental clinic before. Chair side whitening is the most damaging whitening process. I would suggest to go for a bring home kit instead which will take about a 2 weeks and that you can bleach it to the white u want. Chair side usually takes u hours on the dental chair before it can give u the results. Both methods will leave u sensitive in the long run. So please use either the toothpaste for sensitive teeth or the enamel protect after that.
This was the insider details I got from the dentist when I was working there.