teeth whitening after braces?

What is a good affordable teeth whitening kit after having your braces removed? Affordable but still AFFECTIVE. Thanks so much! :)
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Crest White-strips work really great! You really see a difference. I Use them and my teeth are Pitch White ! :) But don't use them too often or keep them on too Long. It tells you on the box how to use them, when I first tried them I was 13 or 14? And I didn't read the instrustions and I used them way too often and now my teeth are Sensitive. SO make sure you don't use them TO often ! (:
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