Teeth Sensitivity

TEETH SENSITIVITY

Many of us say we have "sensitive teeth." We usually mean that we feel twinges of pain or discomfort in our teeth in certain situations, including:
Drinking or eating cold things
Drinking or eating hot things
Eating sweets
Touching the teeth with other teeth or the tongue
There are two types of tooth sensitivity:
Dentinal sensitivity occurs when the dentin (middle layer) of a tooth is exposed. Normally, the dentin is covered by enamel above the gumline and by cementum below the gumline. Dentin is made up of tiny openings called tubules. Inside each tubule lies a nerve branch that comes from the tooth's pulp (the center of the tooth). When the dentin is exposed, cold or hot temperature or pressure can affect these nerve branches. This causes sensitivity.
Dentinal sensitivity can affect one or more teeth. Dentinal sensitivity occurs when the outer protective layers of enamel or cementum are removed, exposing the dentin. Some causes of dentin exposure include:
Brushing your teeth too hard. This wears away the enamel layer.
Poor oral hygiene. This may allow tartar to build up at the gum line, leaching minerals from the tooth.
Long-term tooth wear
Untreated cavities
An old filling with a crack or leak
Receding gums that expose the tooth's roots. Receding gums often are caused by periodontal diseases or by brushing too hard.
Gum surgery that exposes a tooth's roots
Excessive tooth whitening in people who have tooth roots that already are exposed
Frequently eating acidic foods or drinking acidic beverages
Pulpal sensitivity is a reaction of the tooth's pulp. The pulp is a mass of blood vessels and nerves 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
A cracked or broken tooth
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 changes from cold sensitivity to hot sensitivity, the tooth's nerve may be dying. In this case, root canal treatment is necessary.
Diagnosis
Your dentist will look at your dental history and will examine your mouth. He or she will ask about your oral habits. 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.
A tooth may be sensitive to cold for several weeks after a filling is placed. The metals in amalgam (silver) conduct the cold very well, transmitting it to the pulp. Bonded (tooth-colored) 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 now make it less likely to cause tooth sensitivity.
Your dentist or endodontist can conduct tests to see if you need root canal treatment.
Expected Duration
If your tooth becomes sensitive after a silver filling is placed, the sensitivity should go away in several weeks. Some sensitivity may not go away over time. This means the tooth probably needs a root canal.
Sensitivity in more than one tooth may disappear in a short time or it may continue. It depends on the cause of sensitivity. 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
Dentinal sensitivity — You might be able to reduce your chances of dentinal sensitivity by:
Brushing twice a day and flossing daily
Using a soft or ultrasoft toothbrush and brushing gently up and down, rather than side to side
Using a fluoride toothpaste and mouth rinse
Using a toothpaste that has the American Dental Association (ADA) Seal of Approval and provides protection against sensitivity
Getting treatment for grinding or clenching your teeth (bruxism)
Pulpal sensitivity — If a tooth needs root canal treatment, there is no good way to prevent pulpal sensitivity other than to get the needed treatment. Delaying root canal treatment may result in further problems and is not recommended.
Treatment
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 to protect your teeth. This temporarily reduces sensitivity. It also strengthens your teeth. Your dentist also may apply an in-office treatment for sensitivity. These products block the openings (tubules) in your teeth and reduce sensitivity.
Using fluoride toothpastes and fluoride mouth rinses at home also will help to reduce sensitivity. Toothpastes are available just 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.
Pulpal sensitivity can be treated with a root canal if the tooth's nerve is damaged or dying. If the sensitivity is from a new amalgam (silver) filling, it should go away on its own in several weeks. In some cases, a new filling may be too "high" and may be causing sensitivity. Your dentist can polish the filling in this case. Sensitivity caused by grinding or clenching should diminish as the condition is treated.