Does the taste of ice or a sip of hot coffee cause painful experiences? Do you occasionally drive together when brushing your teeth or flossing? If so, you may have sensitive teeth. As you may know, healthy teeth have a layer of enamel that protects your dental crowns. Under the gum line, a layer called cement protects the tooth root. Under the enamel and the cement is dentin. Dentin is less dense than enamel and cement and contains microscopic tubules. When dentin loses its protective layer of enamel or cement, these tubes can get heat and cold or acidic or sticky foods into the nerves and cells in the tooth. Dentin can also be exposed when the gums go back. The result can be hypersensitivity. To understand the difference between hot and cold sensitivity, watch this video.