I was in Thailand and decided to have my teeth whitened due to the cost. I read some reviews after I had booked the appointment and was really concerned mainly about the pain. Anyway when I arrived i was told that i would probably feel some sensitvity whilst the treatment was being carried out and up to a couple of days later.
The first stage was done and then the following 3 and no pain or sensitvity whatso ever. I use a sensitive toothpaste so maybe that was why . the only soreness i got was in the corners of my mouth from holding the shield for so long. teeth are lovely and white - no pain either during or after would totally recommend it