Dentin hypersensitivity

Dentin hypersensitivity (DH, DHS) is dental pain which is sharp in character and of short duration, arising from exposed dentin surfaces in response to stimuli, typically thermal, evaporative, tactile, osmotic, chemical or electrical; and which cannot be ascribed to any other dental disease. A degree of dentin sensitivity is normal, but pain is not usually experienced in everyday activities like drinking a cooled drink. Therefore, although the terms dentin sensitivity and sensitive dentin are used interchangeably to refer to dental hypersensitivity, the latter term is the most accurate. The pain is sharp and sudden, in response to an external stimulus. The most common trigger is cold, with 75% of people with hypersensitivity reporting pain upon application of a cold stimulus. Other types of stimuli may also trigger pain in dentin hypersensitivity, including: Thermal – hot and cold drinks and foods, cold air, coolant water jet from a dental instrument. Electrical – electric pulp testers. Mechanical–tactile – dental probe during dental examination, periodontal scaling and root planing, toothbrushing. Osmotic – hypertonic solutions such as sugars. Evaporation – air blast from a dental instrument. Chemical – acids, e.g. dietary, gastric, acid etch during dental treatments. The frequency and severity with which the pain occurs are variable. The real cause of dentine hypersensitivity is controversial. There have been several theories put forward to try and explain the cause of dentine hypersensitivity. These include the odontoblastic transduction theory, the neural theory and the hydrodynamic theory. The most commonly accepted model is called the hydrodynamic or fluid movement theory proposed by Brannstrom in 1964. According to this theory, when the exposed dentine surface is subjected to thermal, chemical, tactile or evaporative stimuli, the flow of the fluid within the tubules will be increased. Fluid movement inside the dentinal tubules may be away from or towards the pulp.