Teeth Sensitivity

Teeth sensitivity 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 microns 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.

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.

Prevention

Before the proper treatment for a patient is defined, it is important to first prevent, modify, eliminate or control etiologic factors such as plaque, improper toothbrushing, and a diet high in fermentablecarbohydrates and/or acidic foods.^]

Some examples of acidic foods are fruits, fruit juices and wine whose acids can remove smear layers and open dentinal tubules. Toothbrushing with abrasive toothpaste may abrade the dentin surface which may open up dentinal tubules if combined with erosive agents. One recommendation for patients is to avoid toothbrushing for at least two to three hours after consuming the above mentioned acidic foods or drinks.

There are different options to treat dentine hypersensitivity that can be divided in at-home treatments, those the patient can apply, and in-office treatments, those applied by the dentist.

At-home treatments include desensitizing toothpastes or dentifrices, potassium salts, mouthwashes and chewing gums.

Desensitizing toothpastes containing potassium nitrate have been used since the 1980s while toothpastes with potassium chloride or potassium citrate have been available since at least 2000. It is believed that potassium ions diffuse along the dentinal tubules to inactivate intradental nerves. However, as of 2000, this has not been confirmed in intact human teeth and the desensitizing mechanism of potassium-containing toothpastes remains uncertain. Since 2000, several trials have shown that potassium-containing toothpastes can be effective in reducing dentine hypersensitivity, although rinsing the mouth after brushing may reduce their efficacy.

Studies have found that mouthwashes containing potassium salts and fluorides can reduce dentine hypersensitivity, although rarely to any significant degree.^[6] As of 2006, no controlled study of the effects of chewing gum containing potassium chloride has been made, although it has been reported as significantly reducing dentine hypersensitivity.

In-office treatments might be much more complex and they may include the application of dental sealants, having fillings put over the exposed root that is causing the sensitivity, or a recommendation to wear a specially made night guard or retainer if the problems are a result of teeth grinding. 

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