I went in for a routine checkup and both the assistant and dentist said i had "perfect teeth" for a whitening; I've been noticing my yellowing teeth for some time, I've never had a whitening nor used whitening products other than toothpaste and mouthwash so I decided why the heck not. They told me "some teeth sensitivity will occur" but I was not at ALL prepared for the absolute excruciating pain my mouth would be in. I felt my first "zinger" in the last few minutes of the first block, and as she applied more bleach my teeth began to throb. Thinking that this was the "standard" sensitivity i toughed it out through the second block- by the end of it was nearly in tears. I had to stop (there goes $300) and not only did she apply fluoride and give me ibuprofen, but they had to apply varnish to my teeth to stop the throbbing. Nothing is working so far, I haven't nor will I be able to eat all day, and I'm in so much pain I haven't stop crying since I left the office two hours ago. Not only did i waste $300 but I'm forced to take a PTO day because I can barely move my mouth, let alone talk or function in an office. I'm in my twenties, and my teeth have never displayed this level of sensitivity in my entire life, so this isn't just an overreaction. Please try Crest White Strips or something before you even think about this procedure, especially if you think you may have the slightest teeth sensitivity, because the $50 box of Crest White Strips will work infinitely better and cause you exponentially less pain than this Zoom treatment. The best part is there isn't even a contact over at Zoom i can complain to, and I'm certainly not going to blame my dentist for this.