We're very sorry to hear that the spaces between your teeth did not get as white as the rest of the tooth surfaces after using Crest 3D Whitestrips. We can understand your disappointment, and this is certainly not the results we want you to have. Consumer testing and clinical studies have shown that Whitestrips are effective. However, if you have stubborn stains you may need to use a second box of Whitestrips to achieve the results you want. Our Crest Team would like to talk with you more about your experience, and ask that you please give us a call at 1-800-395-8423 from 9AM -- 6PM EST Monday – Friday. We'll be happy to further assist you.

We’re very sorry to hear that you didn’t get the results you were hoping for, Patty. Consumer testing and clinical studies have shown that Whitestrips are effective. However, if you have stubborn stains, you may need to use a second box of Whitestrips to achieve the results you want. If you have any further questions or need assistance, please feel free to call us at (800) 566-7252.