Crest® 3D White™ Professional Effects Whitestrips® Provide Professional Level Whitening. Whitening results that lasts up to 12 months. Featuring Advanced Seal Technology, these no-slip Whitestrips allow you to talk, drink water and go about your day while you whiten with no sticky mess. Use for 30 minutes, once a day for a stand-out smile. Plus, you'll start seeing results after just 3 days. Full results after completion of kit.