How long can I leave bleaching trays on?

Question

I used 22% last night while I slept in my custom bleaching trays. My gums are sore but I'm ok. Should I do/not do this again? How long do you leave yours in?

Answer 1

I slept with them overnight, and it wasn't a problem. Minimum time is suppose to be 30 minutes. If your gums hurt because of the trays, don't sleep with them on again.  

Answer 2

We don't reccomend it any longer, an hour is enough...the material slowly deactivates over time and becomes less effective through the night....pluss you get the seepage and then burning....I wouldn't do it.