What it does: Used once a week, the paste polishes teeth almost as well as a professional cleaning, says the company.
What's in it: ActivClean Crystals (a patented polymer) and finely ground silica.
How it works: The silica, which is larger and more abrasive than the kind in daily toothpastes but less harsh than that in professional pastes, gently scrubs away stains. ActivClean Crystals dissolve in saliva to clean the teeth.
What an expert says: "This mild abrasive is good for removing stains and preventing tartar buildup between dentist visits," says Mark S. Wolff, associate dean for predoctoral clinical education at New York University College of Dentistry. "However, this formula doesn't contain fluoride, so it's not a replacement for regular toothpaste".
What I say: The paste is gritty and felt strange - though it didn't make my teeth noticeably whiter, they felt smoother than they had in months after just one use.