Question: how often can you use crest 3d white strips in a year?
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.