i just bought a Crest whitening strips, and it doesnt cover the whole teeth??:?

hi,i just bought a Crest whitening premium plus whitening, and well, i opened the top 1 first, and put it on, but it doesnt cover everything, just like the front teeth, same with the bottom ones. cuz this way, it will make only the front teeth whiter and the sides would be like yellow? also, just to make sure, u take off the plastic and throw it out, and from wuts left, u stick the side that has the gel on ur teeth right? and do they actually work? any other tips i should know? lol thanks, hope to hear soon
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That is the way they are supposed to be. when you put them on, leave them for 30 minutes than take them off, I always brush my teeth to get rid of the extra gel.
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