How dark are the teeth?
For mild discoloration, or for someone who wants minor color change, try crest whitestrips or cao sheerwhite!.
But if you want a moderate or major color change, see your dentist.
I have had great success with 1 or 2 in- office zoom! led treatment and dispense custom fit home trays with either 10%, 16% or 22% nitewhite or 14% daywhite. Or kor whitening system.