Tooth sensitivity is caused by a wearing away of the tooth’s outer surface or recession of the gums. When the inner layer(dentin) of the tooth or the roots is exposed, tiny channels called dentinal tubules are stimulated.
When hot or cold foods, cold air or pressure touches these channels, the tooth feels sensitive usually experienced as a sudden, sharp pain. It may recede immediately or linger for a while. Because sensitivity may mean different things to a patient and dental professional, be sure to clarify exactly what you feel when you discuss the condition with your dentist. Be sure to tell the dentist when the pain started and what relieves it, such as rinsing with warm water.
Causes of tooth sensitivity
There are two main types of tooth sensitivity:
- Dentinal sensitivity
- Pulpal sensitivity
Dentinal sensitivity usually affects more than one tooth. Causes of dentinal sensitivity include:
- Overzealous brushing leading to wear of enamel and/or recession of the gumline
- Tooth wear due to abnormal chewing or eating habits
- Tooth Decay
- An old filling with a crack or leak
- Gum recession, which exposes the tooth’s roots. The recession is often caused by gum disease or because of tooth grinding (bruxism).
- Gum surgery that exposes the tooth’s roots
- Excessive bleaching of the teeth for tooth whitening especially in people with already exposed root surfaces
Pulpal sensitivity is a reaction of the tooth’s pulp, the core of the tooth with blood vessels and nerves. Pulpal sensitivity tends to affect only a single tooth. Causes include:
- Decay or infection
- A recent filling
- Excessive pressure from clenching or grinding
- A "high" filling - sometimes a newly-done filling comes into contact before the other teeth and causes a sharp shooting pain.
- If you experience a sharp pain upon biting, you may have a cracked tooth or a broken or cracked filling.
Preventing tooth sensitivity
Some toothpastes contain abrasive ingredients that may be too gritty for people who have sensitive teeth. Ingredients found in some whitening toothpastes may also increase tooth sensitivity.
Pulpal sensitivity — When this occurs, it usually indicates the need for a filling, or more often, a root canal. If you grind or clench your teeth (bruxism), being treated for this condition with a nightguard may help.
Dentinal sensitivity — You might be able to reduce your chances of dentinal sensitivity by:
- Using a soft toothbrush and brushing gently in an up and down fashion, rather than side to side, to prevent wear of the enamel
- Practicing good oral hygiene, which can minimize the buildup of tartar and prevent gum disease, which can lead to tooth sensitivity
- Using a fluoride toothpaste and mouth rinse
- Getting treated for grinding and clenching(bruxism)
Treatment for tooth sensitivity
A complete evaluation by your dentist is essential in figuring out the cause of your sensitivity. Any cavities that need to be treated can be taken care of at this time.
True tooth sensitivity can be reduced by using a desensitizing toothpaste, applying sealants and other desensitizing filling materials including fluoride by your dentist, and decreasing the intake of acid-containing foods. In most cases, these products must be used on a regular basis for about a month before any benefit is observed. Avoid using hard bristled toothbrushes and brushing your teeth too hard, which can wear down the tooth’s enamel.
If the sensitivity results from a new amalgam or tooth-colored filling, it will subside in a few weeks without treatment. Sensitivity arising from bruxism should diminish as the bruxism is treated, usually with a nightguard or by balancing the bite.
A thorough dental cleaning by your dentist or dental hygienist is a key part of treatment; the cleaning will remove the dental plaque, which makes the teeth sensitive by releasing certain acidic substances. If your teeth are too sensitive to be cleaned, your dentist may use a local anesthetic before the cleaning.
After a cleaning, your dentist may apply a sealant to protect your teeth. This reduces the sensitivity while remineralizing your teeth, making them less sensitive in the long term.
At home, the use of fluoride toothpastes and mouth rinses also will block these tubules. Toothpastes are also available specifically for sensitive teeth; they contain compounds to block the tubules.
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