Want to transform your smile in just 1 week? Try Crest 3DWhitestrips 1 Week Smile Transformation. This at-home teeth whitening treatment will make your smile 8 levels whiter in 7 days with a comfortable, no-slip teeth whitening experience. This teeth whitening kit includes two 1-week kits so you can keep your smile radiant. We recommend using a 1-week treatment every 6 months. It’s accepted by the American Dental Association for safety and effectiveness and uses the same enamel-safe whitening ingredient as dentists.