The Causes of Dental Sensitivity Dental sensitivity is very common. Sensitivity to eating and drinking hot and cold is not normal and may be indicative of disease. What are the causes? Tooth decay. As a cavity grows and comes closer to the nerve of one’s tooth the thermal layer that was covering the nerve is now thinner. Gum disease. Gun disease, because of bone loss, uncovers portions of the root surface. The root, by definition, lacks that protective enamel covering and can be sensitive to hot or cold. The nerve of the tooth is sick. Due…