Where does sensitive tooth pain come from? Receding gums and damage to your enamel can expose thousands of microscopic channels which lead to your tooth's nerve center. 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 Enamel Repair Toothpaste work? Colgate Sensitive Pro-Relief is a clinically proven formula that works fast, within two weeks, to provide relief to the nerve and builds a protective shield to help prevent painful sensitivity flare-ups when used as directed.