Overview
Dentinal hypersensitivity (DH) is characterized by short, sharp pain arising from exposed dentine in response to stimuli — thermal, evaporative, tactile, osmotic, or chemical — that cannot be ascribed to any other dental defect or pathology.
The hydrodynamic theory is the universally accepted mechanism: fluid movement within dentinal tubules stimulates mechanoreceptors (A-delta fibers) at the pulp-dentin junction, generating pain.
DH requires two conditions: dentin exposure (loss of enamel or cementum) AND patent (open) dentinal tubules communicating with the pulp. Both conditions must be present simultaneously.