Dentine Hypersensitivity

Dentine hypersensitivity is sensation felt when the nerves inside the dentin of the teeth are exposed to the environment. The sensation can range from irritation all the way to intense, shooting pain. This sensitivity can be caused by several factors, including wear, decaying teeth or exposed tooth roots.

Dentine contains many thousands of microscopic tubular structures that radiate outwards from the pulp; these dentinal tubules are typically 0.5-2 micrometres in diameter. Changes in the flow of the plasma-like biological fluid present in the dentinal tubules can trigger mechanoreceptors present on nerves located at the pulpal aspect thereby eliciting a pain response. This hydrodynamic flow can be increased by cold, air pressure, drying, sugar, sour (dehydrating chemicals), or forces acting onto the tooth. Hot or cold food or drinks, and physical pressure are typical triggers in those individuals with teeth sensitivity.

Treatment can consist of amorphous calcium and phosphate, NovaMin, potassium nitrate, strontium chloride, gluma, fluoride therapy, or calcium sodium phosphosilicate.

Potassium nitrate is commonly used in toothpastes such as Sensodyne or Crest Sensitive as a remedy and is approved as a monographed drug by the FDA. Nonetheless, there remains some dispute about its effectiveness. Strontium chloride and strontium acetate are used in Sensodyne Original and Sensodyne Mint toothpastes. The mode of action is linked to their ability to form mineralised deposits within the tubule lumen and on the surface of the exposed dentine that help prevent transmission of the applied stimulus.

One cause of sensitive teeth can be traced to nocturnal gastroesophageal reflux disease (acid reflux). Stomach acid can reach the teeth and cause enamel loss and prevent re-mineralization.