Dental hypersensitivity may be defined as pain arising from exposed dentin typically in response to tactile, thermal, chemical or osmotic stimuli that cannot be explained as arising from any other form of dental defect or pathology. Grossman described it as an uncommonly sensitive or painful response of the exposed dentin to an irritation.
Attrition : The physiologic wearing away of a tooth as a result of tooth to tooth contact as in mastication.
Abrasion : Is the pathologic wearing away of tooth substance through some abnormal mechanical process
Erosion : Erosion is the loss of tooth substance by a chemical process that does not involve known bacterial action.
Incidence and Distribution
Hypersensitivity has been stated that it ranges from 8 to 30 percent of adult populations. Most sufferers range from 20-40 yrs and peak occurrence is found at the end of 3rd decade.
The reducing incidence of dentin hypersensitivity in older individuals despite increasing dentin exposure, with age, particularly through gingival recession presumably reflects age changes in dentin and the pulp, sclerosis of dentin, layering down of secondary dentin and fibrosis of pulp would all interfere with the hydrodynamic transmission of stimuli through exposed dentin
Etiology & Predisposing Factors
Dentin may be exposed by two processes either by enamel loss or loss of covering periodontal structures termed as gingival recession.
Loss of enamel could be due to: - habits or Para functional activity such as bruxism and habits such as tooth brushing or by erosion by dietary components particularly acids and exposure of root dentin by gingival recession.