Unique whitening formula with Pro-Argin technology and CalSeal technology. Where does sensitive tooth pain come from? Receding gums can expose thousands of microscopic channels which lead to your tooth's nerve centre. When your teeth make contact with something hot, cold or sweet, sensations are carried down these channels directly to the nerves, causing pain. How does Colgate Sensitive Pro-Relief Smart White work? Pro-Argin Technology: Pro-Argin creates a mineral barrier that blocks exposed channels to the nerves, providing instant and lasting relief. Calseal Technology: Together with Pro-Argin technology, it fortifies the mineral barrier, so the sensitive areas of your teeth are more protected against daily acid attacks. Whitening: Colgate Sensitive Pro-Relief Smart White effectively removes stains for whiter teeth.