Possible causes include:
In healthy teeth, a layer of enamel protects the crowns of your teeth—the part above the gum line. Under the gum line a layer called cementum protects the tooth root. Underneath both the enamel and the cementum is dentin.
Dentin is less dense than enamel and cementum and contains microscopic tubules (small hollow tubes or canals). When dentin loses its protective covering of enamel or cementum these tubules allow heat and cold or acidic or sticky foods to reach the nerves and cells inside the tooth. Dentin may also be exposed when gums recede. The result can be hypersensitivity.
Proper oral hygiene is the key to preventing sensitive-tooth pain. Ask your dentist if you have any questions about your daily oral hygiene routine or concerns about tooth sensitivity.