Never tried these. Used to use the brush on kind but they don't make them anymore...hmm? Luckily, I know someone who can get me the dr's prescribed peroxide gel and boy are my teeth white...woo whoo me :-D
I tried the aquafresh trays in between buying the crest ones and I didnt like them as much, and the new crest ones you only need to wear for 5min instead of the 30 that it used to be when they first came out!
