Does crest whitening strips work?

Question

do they cover your whole tooth or do they leave parts of your teeth yellow?

Answer 1

Yes, they work on the front teeth~the part that the strips covers.

Answer 2

yes, but they can also make your teeth very sensitive and hurt, like mine did.  I couldn't drink anything cold and sometimes even just breathing in through my mouth made my teeth hurt after using them for the time specified.

Also, if your teeth aren't completely straight (mine aren't), then they don't cover them very well. And, they only do the front of your teeth, like maybe 2 inches or so since that is the length of the strip you use.