2004-4-10 2004-4-10 Teeth become sensitive when dentin (the tooth layer covered by enamel under the crown and by cementum under the root) becomes exposed. The microscopic tubules (small hollow tubes) found in dentin are then exposed, allowing sensations of heat and cold or acidic foods to stimulate the nerves and cells within the tooth. 91546 text/html 1.0 EN index,follow sensitive teeth enamel crown dentin heat cold acidic foods cavity family dentistry Nelson Family Dentistry - Sensitive Teeth text