Can i use 3d crest whitestrips supreme more than 1x a year? box says to use once a year. would i get gum recession or teeth problems if i use more?

Ask your dentist: Tooth whitening should be done under the guidance of a dentist, to make sure it is working properly and is not causing any side effects or gum irritation/damage. Although whitestrips are effective for parts of your teeth, they are not nearly as effective as dentist supplied whitening.

Yes, you can: You can use OTC tooth paste or Crest 3D whitening strips or pens as long as you want. However, they are not so effective and/or stable. A professional teeth whitening without laser, followed by home whitening system with custom trays for the long term effect.