Search for Health Information You Need

What Causes Sensitive Teeth

Sensitive teeth refers to the sensation of discomfort or pain when teeth are exposed to certain stimuli such as cold air, cold or hot drinks and foods and sweet foods. About one fifth of the population experience sensitive teeth. Dentinal sensitivity and pulpal sensitivity are the two major types of teeth sensitivity.

Dentinal sensitivity occurs when the middle layer of the tooth called dentin becomes exposed. The dentin of a tooth is normally housed in an outer protective layer that is divided into two parts. A layer of cementum protects the part of the tooth under the gums known as root, while a layer of hard enamel protects the crown of the tooth.

When these protective layers wear away, the dentin becomes exposed. Tiny hollow tubes and canals known as tubules run through the dentin. Each tubule contains a nerve branch that connects to the pulp at the centre of the tooth. When these tubules are exposed to certain external factors, they stimulate the nerves in the tooth, causing pain.

Pulpal sensitivity occurs when the pulp of the tooth (mass of blood vessels and nerves at the centre of a tooth) reacts to stimuli and causes pain. Pulpal sensitivity often affects only one tooth. However, the irritation to the pulp does not necessarily lead to permanent damage of the pulp itself.

Many people with sensitive teeth experience pain when they consume cold food or drinks and sweets. Breathing in through the mouth, biting, chewing and touching the teeth are other common triggers of tooth sensitivity. Less often, hot drinks or foods may induce pain.

In most cases, patients feel pain that only lasts for a short period before it subsides. But, sensitivity or pain that lingers after the stimulus is gone or occurs when consuming hot food or drinks may indicate the need for a root canal treatment. Tooth sensitivity may also indicate other medical problems, especially if any of the following occur:

  • Sensitivity lasts long after stimulus is removed. This may indicate damage to the pulp of the tooth.
  • Sensitivity persists despite treatment. If tooth sensitivity does not subside after four weeks of desensitizing treatment (e.g., with desensitizing toothpaste), it may be indicative of another medical problem or the need for certain types of dental treatment, such as gum graft or root canal treatment.
  • Sensitivity occurs upon biting or chewing. This may occur if there is a crack or fracture in a tooth.
  • A single tooth is sensitive. This may suggest tooth decay or infection that has damaged the pulp of the tooth.

Potential Causes of Sensitive Teeth

In most cases, tooth sensitivity results from dentin exposure, although it may also be a result of the irritation or injury of the pulp of the tooth. Generally, the most common causes of tooth sensitivity include:

  • Tooth abrasion. When the layers protecting dentin are worn away, tooth sensitivity results. This common cause of sensitivity is often due to aggressive brushing of the teeth. Some teeth whitening products (incl. whitening toothpastes) as well as tartar-control toothpastes use ingredients that contribute to the wearing of enamel.
  • Gum recession. When the gums recede (e.g., due to periodontal disease or surgery on the gums), the tooth root becomes exposed, causing increased sensitivity of the tooth. Gum recession happens to be one of the most common causes of tooth sensitivity.
  • Tooth decay or damage to dentures. Cracks and cavities in fillings or crowns can cause tooth sensitivity.
  • Cracks or fractures in teeth. Cracks and fractures in tooth enamel may cause tooth sensitivity and pain, usually when biting or chewing.
  • Bruxism. Pressure on the teeth from excessive grinding or clenching may also cause teeth sensitivity.
  • Recent dental work. It is common for patients to experience lingering discomfort and tooth sensitivity from recent dental work.
  • Frequent vomiting. Digestive acids present in the vomit may contribute to wearing away tooth enamel and cause sensitive teeth.

Treatment and Prevention of Sensitive Teeth

Sometimes, no treatment of sensitive teeth is needed as the pain and discomfort fades over time. However, tooth sensitivity may also indicate a problem that requires treatment, which can be done at home or at the dentist’s office.

At home, patients may use desensitizing toothpaste. It helps to block sensations from traveling from the tooth surface to the nerves. In other cases, sensitive teeth may require treatment in a dentist’s office, such as application of a fluoride gel or another desensitizing agent that temporarily reduces tooth sensitivity.

Maintaining good oral hygiene is the best strategy for preventing sensitive teeth. Regular brushing with a soft brush can help prevent tooth sensitivity. Flossing and professional cleanings can help prevent periodontal disease and tooth decay that cause sensitive teeth.

Where to Get More Information: Colgate