Today is August 24 2010 and I had this procedure done yesterday. The dentist starts out by putting a plastic thing in your mouth that holds your mouth open, then they cover your gums with gauze so that your gums are not exposed. They then put sunscreen on your nose and give you glasses to wear during the whitening. Before they put the Zoom! whitening light on you, they cover your teeth with the bleach. It is 3 rounds at 15 minutes each. I got through round one. In fact, I was so comfortable I start to fall asleep... until the last five minutes were I started to feel the burning of the bleach. At first it is discomfort, but then (as others have mentioned), the "zingers" start.
After round one, the dentist checks on you to make sure you are okay. Immediately comes round two. The discomfort (kind of a dull pain in your gums, coupled with the zingers) was so bad that I actually did not last throughout the second round and finished early with four minutes left. The pain was so much we did not even do the third round, though my dentist said the third round was for people who had really bad stains (like smokers). The dentist kept telling me that the pain would subside 10 minutes after the procedure but that was not true. The duller, annoying pain did go away in a couple of hours, but the zingers continued up until I went to bed around 930 PM (I had the procedure done around 1 PM). The pain was gone the next day (today), and now I am fine. I still feel a tiny bit of discomfort, but no zingers, just a little bit of soreness... but what do you expect, you just bleached your teeth! $500.00 was steep but I think the procedure worked great. My teeth are really white now, which is perfect just in time for my wedding