Works great short term [SEP] This is great for whitening for a specific occasion. My teeth were super white, looked great in photos, received lots of compliments. It doesn't last longterm though, so I wouldn't use it for permanent whitening or maintenance. I have permanent retainers on my teeth, so it's difficult to get strips to stick. This was easy to use with permanent retainers, and you can pop in the goo+tray and watch TV or whatever. I did like the hands-free part, but it does get annoying to have to rinse and reapply the gel every 8 minutes. I would use again in a pinch but would prefer professional whitening longterm though it is the pricier option.