Until now, most home bleaching is performed using carbamide peroxide - a stabilised form of hydrogen peroxide. During use, the carbamide peroxide breaks down to hydrogen peroxide to whiten teeth.
Carbamide peroxide does not need to be refrigerated and has a longer shelf-life, meaning it is easier for distributers to store and ship - however it takes far longer to breakdown during use, meaning up to 8 hours (overnight) wear is required.
Hydrogen peroxide (like in Aura One) get's to work immediately, and is completely broken down within 60 minutes allowing for maximum whitening in just one hour treatment time.