I had my second in-office visit where in that 1 1/2hrs they verified the fit of my trays. They also applied the desensitizer using something that kept my lips wide open and my tongue held back. This was timed and I think it was done twice. Don't remember if the gel was applied, but I don't think so. I was sent home with my trays, gel, instruction video, and written instructions. I watched the video and read the information several times. That first night applying the desensitizer and trays went fine and had no issue. Next day my teeth throbbed all day, and occasionally got a little discomfort from cold/hot. By end of the first day the throbbing was too much and I stopped by my dental office. They gave me a syringe of desensitizer and instructed me not to use any of the at-home procedure that one night and just put this gel in the trays for 30 minutes. The following night I applied the regular desensitizer, keeping my lips away from my teeth as shown in the video just like I did the first night. I then applied the trays with the whitening gel. The discomfort was instant and just kept getting stronger. I tried waiting thinking it would quickly pass but I couldn't stand it. I removed the trays rinsed & cleaned my mouth and noticed my inside lip looked red and irritated. Shortly after I decided to try again thinking it couldn't possibly have been that bad as I'd had no problem the first night. I no sooner put the trays in and it felt like a thousand pin pricks. Quickly removed the trays, rinsed and cleaned my mouth. Next morning I awoke to swollen lips, and a large blister inside my bottom lip and the edges around my mouth are also irritated. The dental technicians thought it was an allergic reaction to the desensitizer and gave me Benadryl to help take down the swelling which it never did. That was 3 days ago and this morning I woke up looking like one of the Muppets. My whole mouth area is still swollen and the blister doesn't look any better even though I've been applying Vitamin E oil and lavender essential oil. Luckily my dental office was able to see me on a Saturday, probably because I was crying hysterically - I'M SCARED and I LOOK LIKE A MUPPET. He gave a Rx for a pill to reduce the swelling but it didn't take the swelling away either. The last thing I'm concerned about at this point is the teeth whitening, I'm worried the swelling will never go down. What happened?