Sensitive teeth refers to the sensation of pain or discomfort when teeth are exposed to stimuli such as cold or hot drinks and foods, cold air and sweet foods. The pain usually lasts for just a few seconds, although it may linger. Many patients with sensitive teeth experience the symptom repeatedly over a long period of time.
There are two major types of sensitivity that affect the teeth:
- Dentinal sensitivity. Occurs when the middle layer of the tooth (dentin) becomes exposed.
- Pulpal sensitivity. Occurs when the pulp (mass of blood vessels and nerves at the center of a tooth) of the tooth reacts to stimuli, causing pain.
Many factors can cause teeth to become sensitive, including periodontal (gum) disease, tooth decay, cracks in teeth, worn tooth enamel, worn fillings, and pressure on the teeth from excessive clenching or grinding (bruxism).
In trying to pinpoint the cause of sensitive teeth, a dentist looks for signs of decay or damage to restoration work. The dentist also looks for exposed tooth roots and may use a metal device with a sharp point (explorer) to check the sensitivity of teeth.
In some cases, no treatment of sensitive teeth is necessary as the symptom fades over time. However, other instances of sensitivity may indicate a problem that requires treatment. Sensitive teeth usually can be treated either at home or at the dentist’s office.
At home, patients may be asked to use desensitizing toothpaste that blocks sensations from traveling from the tooth surface to the nerves. Sensitive teeth also may require treatment in a dentist’s office, such as application of a fluoride gel or other desensitizing agent that helps reduce sensitivity temporarily.
One of the best ways to prevent sensitive teeth is to maintain good oral hygiene. Regular brushing using proper techniques and a soft brush can help prevent sensitive teeth. Flossing and regular professional cleanings can help prevent a number of factors that cause sensitive teeth, including periodontal disease and tooth decay. Patients also are urged to avoid whitening or tartar control toothpastes, acidic foods or drinks, and excessive amounts of diet soda.
About sensitive teeth
Patients with sensitive teeth may experience pain or discomfort when their teeth are exposed to certain stimuli, such as cold or hot drinks and foods, cold air and sweet foods. At least 45 million adults in the United States have sensitive teeth, according to the Academy of General Dentistry.
There are two major types of sensitivity that affect the teeth: dentinal sensitivity and pulpal sensitivity.
Dentinal sensitivity results when the middle layer of the tooth (dentin) becomes exposed. Normally, the dentin of a tooth is housed in an outer protective layer that divides into two parts. A layer of hard enamel protects the top of the tooth (crown) while a layer of cementum protects the part of the tooth under the gums (root).
When the enamel or cementum wears away, it leaves dentin exposed. Tiny hollow tubes and canals (tubules) run through the dentin, and each tubule contains a nerve branch that connects to the pulp at the center of the tooth. When these tubules are exposed to certain stimuli, they stimulate the nerves in the tooth and cause pain.
Pulpal sensitivity occurs when the pulp of the tooth reacts to stimuli, causing pain. The pulp is the mass of blood vessels and nerves at the center of a tooth. Frequently, pulpal sensitivity affects only one tooth. The irritation to the pulp does not necessarily cause permanent damage to the pulp itself.
People with sensitive teeth often feel pain when they eat sweets or cold food or drinks. Patients also may feel pain when chewing, breathing in through the mouth or touching the teeth. Less commonly, hot foods or drinks may cause pain.
In some cases, patients feel pain that lasts for just a few seconds before fading. Sensitivity that lingers after the stimulus is gone may indicate the need for a root canal treatment. Pain that occurs when consuming hot food or drinks may indicate that the nerve in the tooth is dying, a condition that may also require root canal treatment.
Patients with tooth sensitivity are encouraged to speak to their dentist about treatment options. The prognosis for patients with sensitive teeth varies. Some people experience sensitivity that lasts for only a short period before it subsides. Others may experience sensitivity that lasts throughout their lifetimes.
Sometimes tooth sensitivity may indicate other problems. Patients should contact their dentist immediately if any of the following occur:
- Sensitivity occurs long after stimulus is removed. If sensitivity lasts for a length of time (e.g., for more than just several seconds or a minute or two) after exposure to stimuli, it may indicate damage to the pulp of the tooth.
- Sensitivity persists despite treatment. If tooth sensitivity does not decrease after two to four weeks of desensitizing treatment (e.g., regular use of desensitizing toothpaste), patients should consult their dentist. Persistent sensitivity that does not respond to desensitizing agents may indicate another problem or the need for certain types of treatment (e.g., gum graft, root canal treatment).
- A single tooth is sensitive. This may indicate tooth decay or infection that has damaged the pulp of the tooth. Treatment by a dentist is necessary. Even if sensitivity subsides, treatment may be necessary to prevent the spread of infection.
- Sensitivity occurs upon biting or chewing. This may indicate a crack or fracture in a tooth. A dentist can determine the extent of the break and whether the pulp of the tooth has been damaged.
- Sensitivity is accompanied by signs of disease or decay. If the gums change color, or there is an obvious cavity, crack or fracture in the tooth or dental restorations, it may indicate a condition that needs to be treated by a dentist.
Potential causes of sensitive teeth
Teeth may become sensitive for a variety of reasons. Tooth sensitivity occurs most often due to dentin exposure, although it may also occur when the pulp of the tooth is irritated or injured.
Causes of tooth sensitivity include:
- Gum recession. When the gums recede, the tooth root becomes exposed, causing increased sensitivity of the tooth. This is the one of the most common causes of tooth sensitivity. Gum recession usually affects more than one tooth and may be caused by a number of factors, including periodontal (gum) disease and surgery on the gums.
- Tooth abrasion. When the enamel and cementum of teeth are worn away, dentin may become exposed and tooth sensitivity usually results. This is a common cause of tooth sensitivity, usually due to aggressive brushing of the teeth. Some teeth whitening products, including toothpastes, use abrasive ingredients that contribute to the wearing of enamel. Sodium pyrophosphate, used in tartar-control toothpastes, can also make teeth more sensitive.
- Tooth decay or damage to restorations. Cavities and cracks in fillings or crowns are examples of factors that can cause tooth sensitivity.
- Cracks or fractures in teeth. When cracks or fractures in tooth enamel occur, it may cause tooth sensitivity and pain, usually when biting or chewing.
- Recent dental work. Patients may experience lingering discomfort and tooth sensitivity from recent dental work, such as fillings or crowns.
- Bruxism. Pressure on the teeth from excessive clenching or grinding can cause teeth sensitivity.
- Frequent vomiting. Frequent, persistent vomiting (e.g., cyclic vomiting syndrome) may also cause sensitive teeth as the digestive acids wear away tooth enamel.
Diagnosis and treatment of sensitive teeth
A dentist compiles a thorough dental history and performs an examination of the mouth when diagnosing the source of sensitive teeth. During the examination, the dentist looks for signs of decay or damage to restoration work. The dentist also looks for exposed tooth roots and may use a metal device with a sharp point (explorer) to check the sensitivity of teeth.
In some cases, no treatment is necessary. For example, patients who have recently had an amalgam filling or composite resin filling may experience pulpal sensitivity to cold for several weeks. Amalgam conducts cold easily and transmits it to the pulp, while fillings that bond to the tooth, such as composite resin, sometimes require acid-based etching of the tooth that wears away enough enamel to cause sensitivity. In most cases, sensitivity associated with recent restoration work disappears over time.
However, other instances of sensitivity may indicate a problem that requires the appropriate treatment. Sensitive teeth usually can be treated either at home or at the dentist’s office.
At home, patients who regularly use fluoride toothpaste decrease their vulnerability to sensitivity. In addition, special desensitizing toothpastes are available over-the-counter for patients who have sensitive teeth. These toothpastes contain compounds (e.g., potassium nitrate) that block sensations from traveling from the tooth surface to the nerves. Patients may need to use these toothpastes for up to a month before the desensitizing effect is apparent and continue to use them regularly to maintain the effect.
Product label warnings against long-term use of desensitizing toothpastes are meant to advise patients to consult a dentist about their tooth sensitivity. If tooth sensitivity does not decrease after two to four weeks of regular use of a desensitizing toothpaste, it may indicate another problem that requires treatment by a dentist. Desensitizing toothpaste has not been tested on children under the age of 12, and is not generally recommended for this age group.
Use of fluoride mouth rinses also may decrease sensitivity for some patients. Patients considering using a mouth rinse are urged to speak with their dentist about the best available options. It is best to avoid acidic rinses and to instead use rinses with neutral sodium fluoride. When purchasing over-the-counter dental products, it is important to look for the American Dental Association Seal of Acceptance.
Sensitive teeth also may require treatment in a dentist’s office. Some patients who have sensitive teeth may need a local anesthetic or nitrous oxide before having their teeth cleaned in a dentist’s office. In addition, dentist can apply a fluoride gel or varnish, or other desensitizing agents (e.g., bonding, sealants) to the teeth that help reduce sensitivity temporarily. Some treatments block the tubules in the teeth to keep them from transmitting stimuli to the pulp. Others bond to the tooth root and act as a seal over the sensitive teeth.
If these treatments fail to reduce a patient’s sensitivity, other procedures may be necessary. Sensitive teeth may be the result of tooth decay that may need to be treated with a restorative procedure such as a filling, crown or inlay. When lost gum tissue causes the sensitivity, patients may require surgical gum graft to cover the root of the tooth that is sensitive. If these treatments fail to reduce pain in the tooth, a root canal treatment may be necessary.
Finally, some instances of sensitive teeth can be reduced or eliminated by treating an underlying condition. For example, pulpal sensitivity resulting from grinding or clenching of teeth (bruxism) usually goes away once the underlying condition is treated.
Researchers continue to investigate new, better treatments for sensitive teeth. For example, some scientists are looking into the use of a tiny particle to bond with and strengthen tooth enamel as a long-term treatment.
Prevention methods for sensitive teeth
One of the best ways to prevent sensitive teeth is to maintain good oral hygiene. Regular brushing, flossing and dental examinations can help prevent a number of factors that cause sensitive teeth, including tooth decay and periodontal (gum) disease.
However, patients are urged to consult their dentist if they are unsure of proper oral hygiene techniques. Well-intentioned but incorrect techniques (e.g., brushing too hard, snapping floss against the teeth and gums) can injure the gums, exposing the roots of the teeth and increasing sensitivity. Brushing too hard is often an ingrained habit. A person is brushing too hard if the bristles on the brush are pointing in several different directions.
Patients are urged to brush gently with a soft-bristled toothbrush, or to use a powered toothbrush that has a pressure sensor. This type of brush stops working when the patient applies too much pressure during brushing.
Patients may be advised to avoid using teeth whitening solutions, including whitening or tartar control toothpastes, which can increase tooth sensitivity. Regular use of desensitizing toothpaste may be recommended to maintain the teeth’s resistance to stimuli.
Acidic foods (e.g., citrus fruits, tomatoes, pickles, tea) and excessive amounts of diet soda should be avoided because they may also increase tooth sensitivity. Patients should also refrain from using tobacco since it can cause receding gums and lead to increased sensitivity.
Questions for your doctor about sensitive teeth
Preparing questions in advance can help patients to have more meaningful discussions with their dentists regarding their conditions. Patients may wish to ask their doctor the following questions about sensitive teeth:
- What steps can I take to reduce sensitivity in my teeth?
- How will I know if I should have my sensitive teeth checked by a dentist?
- What are the signs that my sensitive teeth may result from a more serious dental problem?
- What do you suspect is the cause of my sensitive teeth? Why do you think that?
- If I experience pain after a filling, how long might it last before it indicates a problem?
- If I have desensitizing gel or other treatment applied in a dental office, how long will it last?
- Is there another option besides surgery for covering my exposed tooth root?
- Can you suggest a good mouth rinse and toothpaste for me?
- What should I do if my desensitizing toothpaste still is not effective after one month?
- Do you know of a good toothbrush with a pressure sensor?