Purchased coupon online, so it wasn't as expensive. Went to my regular dentist for cleaning, x-rays, & check-up a couple days before Zoom. I've *never* had sensitive teeth or any tooth pain before and I was not uncomfortable during the zoom process - the light felt sort of warm on my teeth but it wasn't uncomfortable and I had no gum irritation or anything.
I had 3 15-minute sessions with the UV light and no real pain (just dry mouth from having my mouth held open for an hour). But about an hour later my teeth started to hurt and the pain has increased over the last several hours - I haven't had many of the sharp, shooting pains others have described (though the hygienist warned me about these 'zingers') but I definitely have a constant throbbing pain in my front teeth (top & bottom) from the procedure. They do look whiter and brighter than before, but they weren't *terrible* before so I'm reserving judgment yet on whether or not this was worth it.
If the pain goes away by tonight or early tomorrow and my teeth stay this bright, then I will probably consider it worthwhile. But if the pain gets much worse or goes on for more than another few hours, I'd have to say I don't recommend it overall. I'll repost in a week once I'm off the "white food" diet and let you know how it looks and feels.