Question: how many times a year can you use crest whitening strips?
Answer: With that said, Crest 3D Whitestrips will whiten teeth for at least six to 12 months, so we recommend using Whitestrips twice per year to maintain a whiter smile. If you feel you are not seeing desired results, we suggest trying Crest 3D Whitestrips Professional Effects or consulting a dentist.