What Is It?
Many of us speak of having "sensitive teeth." We usually mean that we feel twinges of pain or discomfort when our teeth encounter certain stimuli, including:
 
▪ Cold food or drink
▪ Less often, hot food or drink
▪ Sweets
▪ Touch

There are two main types of tooth sensitivity:

Dentinal sensitivity occurs when the dentin (middle layer) of a tooth is exposed. Normally, the dentin is protected. The part of the tooth above the gumline is covered with enamel and the tooth's roots are covered with cementum.

The dentinal layer is made of tiny openings called tubules. Inside each tubule lies a tiny nerve branch that comes from the tooth's pulp chamber in the center of the tooth. When the dentin is exposed and a stimulus, such as those listed above, can reach these nerve branches, sensitivity can occur.

Dentinal sensitivity can affect one or more teeth, depending on the cause. Causes include:

▪ Too-vigorous brushing that wears away the tooth surface
   (enamel and/or cementum)
▪ Poor oral hygiene that allows tartar to build up at the gum line, leaching
   minerals from the tooth
▪ Long-term tooth wear
▪ Decay
▪ An old filling with a crack or leak
▪ Gum recession, which exposes the tooth's roots. The recession is often
   caused by periodontal disease
▪ Gum surgery that exposes the tooth's roots
▪ Excessive tooth whitening in people with root surfaces already exposed

Pulpal sensitivity is a reaction of the tooth's pulp, a mass of blood vessels and nerves that sits in the center of each tooth. Pulpal sensitivity tends to affect only a single tooth. Causes include:

▪ Decay or infection
▪ A recent filling
▪ Excessive pressure from clenching or grinding

If you experience a sharp pain upon biting, you may have a cracked tooth or a broken or cracked filling.


Symptoms
Both dentinal and pulpal sensitivity usually involve reactions to temperature or pressure. Sensitivity to cold drinks or foods is the most common symptom. Less often, the teeth are sensitive to hot temperatures. If a single tooth progresses from cold sensitivity to hot sensitivity, it may indicate that the tooth's nerve is dying, and root canal treatment (endodontic therapy) is necessary. If single-tooth sensitivity continues for some time after the stimulus is gone, the tooth is more likely to require root-canal treatment than if the sensitivity lasts only seconds.


Diagnosis

Your dentist will look at your dental history and will examine your mouth. He or she will ask about your oral habits because grinding or clenching your teeth can contribute to sensitivity. Your dentist also will look for decay, deep metal fillings and exposed root surfaces. He or she may use an explorer — a metal instrument with a sharp point — to test teeth for sensitivity.

If you have one sensitive tooth and it has recently had a filling — either an amalgam filling or a bonded composite resin filling — it may be sensitive to cold for several weeks. The metals in the amalgam conduct the cold very well, transmitting it to the pulp. Bonded fillings require etching the tooth with acid before the filling is placed. In some cases, this etching removes enough enamel to make the tooth sensitive. However, advances in bonding technique now make it less likely the procedure will cause tooth sensitivity.

Your dentist or endodontist will conduct sensitivity tests that can determine if root canal treatment is needed.
 

Expected Duration
Sensitivity that occurs after an amalgam filling is placed will go away in several weeks. However, if the tooth requires a root canal, the sensitivity will not disappear over time.

Sensitivity that occurs in multiple teeth may disappear in a short time or may continue. Every case is different. Some people have sensitive teeth for only a month or two. Others have the condition for much of their lives.


Prevention

Pulpal sensitivity — There is no good way to prevent pulpal sensitivity that occurs because the tooth needs root canal treatment. If you grind or clench your teeth (bruxism), being treated for this condition may help to prevent the pulp from being overly sensitive.

Dentinal sensitivity — You might be able to reduce your chances of dentinal sensitivity by:

▪ Practicing good oral hygiene, which can minimize the buildup of tartar and
   prevent periodontal (gum) disease, which can lead to sensitivity
▪ Using a soft brush and brushing gently up and down, rather than side to side,
   to prevent abrasion of the enamel
▪ Using a fluoride toothpaste and mouth rinse
▪ Using a desensitizing toothpaste that has the American Dental Association
   (ADA) Seal of Approval and provides protection against sensitivity
▪ Getting treatment for bruxism


Treatment
Pulpal sensitivity can be treated with a root canal in cases where the sensitivity indicates that the tooth's nerve is damaged or dying. If the sensitivity results from a new amalgam filling, it should subside without treatment in several weeks. Sensitivity caused by bruxism should diminish as the bruxism is treated.

Dentinal sensitivity is quite treatable, whatever the cause.

Your dentist or dental hygienist will clean your teeth. If your teeth are too sensitive to be cleaned, your dentist may use a local anesthetic or nitrous oxide before the cleaning.

After a cleaning, your dentist may apply a fluoride varnish-based treatment to protect your teeth. This reduces the sensitivity and strengthens your teeth. This treatment reduces sensitivity temporarily. Your dentist also may apply an in-office treatment for sensitivity. These products contain substances that block the openings (tubules) in your teeth and reduce sensitivity.

At home, the use of fluoride toothpastes and mouth rinses also will help to reduce sensitivity. Toothpastes are also available specifically for sensitive teeth.

Talk to your dentist about which fluoride rinses you should use. Some over-the-counter rinses are acidic. Others are not. You should choose a fluoride mouth rinse that uses neutral sodium fluoride.


When To Call A Professional
If you have sensitivity that lasts for longer than a few weeks, contact your dentist. Or if you have a scheduled cleaning coming up soon, talk to your dentist then about your sensitivity and possible causes. Most cases of tooth sensitivity are treated easily.


Prognosis
The outlook is different for each individual. Some people have only short-term tooth sensitivity, while others deal with the condition for many years.


Additional Information
American Dental Association
211 East Chicago Ave.
Chicago, IL 60611
Phone: (312) 440-2500
Fax: (312) 440-2800
http://www.ada.org/

 

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