how do i get really white teeth? my dentist said i don't need whitening but i think i do?

my friends have lovely white teeth and i would like mine that colour too, is there anything not harmful i can try at home?
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If you can afford it, go to a cosmetic dentist and get the procedure done there; it takes about an hour and the results are outstanding. If you want it to be inexpensive, use Crest whitening strips, you'll see results in 7 days.
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