Dentinal Hypersensitivity is commonly known as tooth sensitivity. If a person feels mild to severe discomfort or pain on consuming hot, cold, or sweet food and drinks or breathing in cold air, it indicates sensitive teeth. It is a very common clinical presentation and causes considerable concern for patients. Studies showed that in most populations, 10-30% of the general population suffer from dentinal hypersensitivity.
Dentine hypersensitivity (DH) is defined as short, sharp pain arising from exposed dentine, typically in response to chemical, thermal or osmotic stimuli that cannot be explained as arising from any other forms of dental defect or pathology.
-(Addy & Dowell, 1983)
It is common in people of age 20 - 40 years, with the peak incidence occurring at the end of the third decade and decreases during the fourth and fifth decades of life. Women are affected more than men.
The tooth has outer enamel layer that protects the dentin underneath. The dentin comprises of microscopic tubules or canals that are connected to the pulp of the tooth. If dentin loses its protective covering of enamel its tubules get exposed. These tubules allow heat, cold or acidic foods to reach the nerves and cells inside the pulp of the tooth and the tooth becomes sensitive.
Several theories have been proposed to explain the mechanism involved in dentinal hypersensitivity such as the transducer theory, the modulation theory, the “gate” control and vibration theory, and the hydrodynamic theory.
The most widely accepted theory is Brannstrom’s hydrodynamic theory, that is fluid movement within the dentinal tubules.
Good oral hygiene is the best defense against most of the oral health problems, including tooth sensitivity. Brushing too hard, applying too much pressure while brushing or using a hard-bristled toothbrush causes tooth abrasions and gingival recessions leading to tooth sensitivity. The American Dental Association recommends to follow a good dental care routine:
The type of treatment will depend on the cause of sensitivity. Sensitivity takes some time to settle.
Treatment includes use of desensitizing toothpastes for use at home; or topical application of desensitizing agents by dentists. These desensitizing agents contain compounds that prevent irritants from stimulating the nerves inside the tooth. Most widely used ingredient is potassium nitrate. Other effective desensitizing agent are dentin sealers (resins), sodium citrate, and sodium monofluorophosphate.
In office treatments are fluoride varnishes, or fluoride gel application, fillings, crowns, inlays or bonding, that can be used to repair the damaged areas of the tooth or to cover the areas exposed by gum recession. Invasive procedures include gingival graft surgery or root canal treatment.