LISTERINE SENSITIVITY with CRYSTAL BLOCK Technology works differently than many sensitivity toothpastes. Our CRYSTAL BLOCK Technology contains potassium oxalate, an ingredient which binds to calcium in your saliva and leads to the formation of calcium oxalate crystals deep inside exposed dentin tubules. Each rinse thus forms crystals that build up deep inside open tubules, blocking 97% of tubules in just 6 rinses* to provide daily repair of damage by creating a powerful barrier for continuous sensitivity protection.** LISTERINE SENSITIVITY starts to work right away***, and the crystals build with every rinse to provide deep, stable, lasting protection. As the crystals build up, tooth pain starts to go away. That usually happens in 2 weeks, with results that last between rinses.** The tubule occlusion is more durable than the occlusion from a leading sensitivity toothpaste that also blocks tubules – even after mechanical and acid challenge.* *In laboratory studies **With continued use ***Relief in 2 weeks with continued use