Please help! what is the best and safest over-the-counter teeth bleaching system?

Depends: 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.

Teeth whitening : You can use over the counter products, however, they are not so effective and/or stable. OTC bleach and whitening tooth paste could be used as a supplement only. A professional teeth whitening without laser, followed by home whitening system with custom trays for the long term effect. You will be very happy with the results.