Tooth sensitivity is a common dental problem that involves discomfort or pain in teeth when encountering certain substances and temperatures. At least 40 million adults suffer from sensitive teeth in the United States, according to the Academy of General Dentistry.

The pain is often sharp and sudden, but it is temporary. According to the Cleveland Clinic, the pain may shoot into the tooth’s nerve endings. Fortunately, sensitive teeth can be treated and the condition can improve.

Causes of tooth sensitivity

There are no at-risk groups for tooth sensitivity. It can happen to anyone, according to Dr. Margaret Culotta-Norton, a dentist in Washington, D.C., and former president of the D.C. Dental Society.

“The most common symptom … is a sudden, sharp flash of pain when teeth are exposed to air, cold, sweet, acidic or hot foods,” she told Live Science. Some people may experience tooth sensitivity from brushing or flossing their teeth.

In healthy teeth, enamel protects the underlying layer of dentin, which is softer than enamel. The tooth roots are protected by gums. But if the enamel is worn down or if the gum line has receded, then the dentin becomes exposed. “Cavities, cracked teeth, gum recession, enamel and root erosion all cause dentin to be exposed,” Culotta-Norton said. “Dentin is connected to the nerve that triggers pain in sensitive teeth.”

Dentin contains thousands of microscopic tubules, or channels, leading to the tooth’s pulp, according to the Academy of General Dentistry. When exposed to the elements, these dentinal tubules allow heat, cold, acidic or even sticky substances to reach the nerves inside the tooth, causing pain.

Some factors that contribute to sensitive teeth may include:

Brushing too hard or using a hard-bristled toothbrush. This can wear down enamel, causing dentin to become exposed, or encourage gum recession.

Gum recession. This often happens in people suffering from periodontal disease, and it exposes the dentin.

Gingivitis. Inflamed and sore gum tissue can result in exposure of the tooth’s root.

Cracked teeth. These can become filled with bacteria from plaque and cause inflammation in the pulp of the tooth. In more severe cases, it may lead to abscess and infection.

Teeth grinding or clenching. This can wear down enamel.

Plaque buildup.

Long-term use of mouthwash. Some over-the-counter mouthwashes contain acids. If dentin is exposed dentin, the acids can make existing tooth sensitivity worse and also further damage the dentin layer. There are neutral fluoride mouthwashes available that might be a better option.

Acidic foods. These can encourage enamel reduction.

Dental procedures. Teeth may be sensitive after professional cleaning, root planing, crown replacement and other tooth restoration procedures. Usually the pain will disappear in four to six weeks.

Tooth sensitivity after filling

Some people may experience tooth sensitivity after having a cavity filled or a filling replaced, according to the Columbia University College of Dental Medicine. The tooth decay that causes cavities irritates the tooth, and the filling procedure, while necessary, can lead to further sensitivity. Fortunately, tooth sensitivity after a filling should improve on its own within a few weeks. It may last longer, as much as a few months, but as long as the tooth sensitivity shows gradual improvement, there should be nothing to worry about. Persistent tooth sensitivity, however, may indicate that a root canal is needed.

Sometimes after a filling, teeth become sensitive when biting down. This can be fixed with a simple bite adjustment. Additionally, the filling may be too high, according to Columbia University. In this case, the dentist could lower the filling.

Composite fillings may cause tooth sensitivity when chewing. There is no pain when the teeth are clenched together, however. This tooth sensitivity is usually fixed by adjusting the bite or replacing the filling with another composite, according to Bear Peak Dental, a private practice in Boulder, Colorado.

Tooth sensitivity after whitening treatments

Teeth-whitening treatments — done either in a dentist’s office or using an over-the-counter product — contain harsh chemicals that remove stains, but they can also remove the enamel, leading to tooth sensitivity. Several studies have investigated ways to lessen pain after in-office teeth-whitening treatments. A 2018 study in Operative Dentistry found that patients taking acetomeniphin/codeine before treatment did not reduce pain, so more dramatic measures are likely needed. A 2016 study in Lasers in Medical Science found that irradiating teeth with a low-level red laser with an infrared diode after a whitening treatment reduced pain levels significantly. A 2018 study published in The Journal of the American Dental Association found that applying a densitizing gel before whitening significantly reduced tooth sensitivity after treatment.

Another potential solution is changing the formula of whitening products. A 2017 study published in Clinical Oral Investigations found that reducing the acidity in bleaching gels resulted in significantly less pain with the same whitening results.

Source: https://www.livescience.com/44377-sensitive-teeth.html