Oooooooo make sure you have pain killers just before you go in as you will be in lots of pain tonight
It starts about an hour after you leave the clinic, well im presuming your having lazer whitening. Good luck and hope the pain isnt too bad mine absolutley killed me and I couldent sleep at all, will be worth it though and follow their instructions like only clear fluids and stuff because I think it does help keep them white I need mine doing again now
have fun x x xx x