your mouth has sipped, snacked, ...yellowed... lived, loved, ...yellowed... chatted, chewed, ...yellowed. and over all those years, your teeth...have yellowed. fact is, if you're not whitening, you're yellowing. crest 3d white whitestrips remove over ten years of stains by going below the enamel surface. and, they whiten 25 times better than a leading whitening toothpaste. crest whitestrips. life opens up when you do.