Dentin, a living tissue within the tooth, is normally nestled under the outer layers of enamel and cementum. It is made up of microscopic tubules filled with a fluid. The dentin may get exposed in various conditions, such as wear of teeth, gum inflammation and recession, etc. When the dentinal tubules are exposed to the oral environment, external stimuli, such as heat, cold, sweet/sour tastes, or touch, may disturb the dentinal fluid. This disturbance is manifested as a sharp pain in the tooth and is known as hypersensitivity.