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. These may include:
- Drinking or eating cold things
- Drinking or eating hot things
- Eating sweets
- Touching the teeth with other teeth or the tongue
- Brushing your teeth too hard. This can wear away the enamel layer.
- Poor oral hygiene. This may allow tartar to build up at the gum line.
- 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
- Tooth whitening in people who have tooth roots that already are exposed
- Frequently eating acidic foods or drinking acidic liquids
- Decay or infection
- A recent filling
- Excessive pressure from clenching or grinding
- A cracked or broken tooth
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 becomes sensitive to heat, the tooth's nerve is dying. In this case, root canal treatment is necessary.
Your dentist will look at your dental history and will examine your mouth. You also will need X-rays to show if there is decay or a problem with the nerve. The dentist will ask about your oral habits. Grinding or clenching your teeth can contribute to sensitivity. Your dentist also will look for decay, deep 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 you get a filling. 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 do tests to see if you need root canal treatment.
If your tooth becomes sensitive after a deep filling is placed, the problem may go away in several weeks. Sometimes the filling is too high. That puts too much pressure on the tooth when you bite down. Your dentist can reduce the height of the filling. If the sensitivity does not go away over time, 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 years.
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 provides protection against sensitivity
- Getting treatment for grinding or clenching your teeth (bruxism)
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 may apply an in-office treatment for sensitivity. These products block the openings (tubules) in dentin and reduce sensitivity. A newer approach is to use a dental laser. The laser treatment also alters the tubules to reduce sensitivity. Using fluoride toothpastes and fluoride mouth rinses at home will help to reduce sensitivity. You also can buy toothpastes 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 will be treated with a root canal if the tooth's nerve is damaged or dying. Your dentist will remove the nerve and place a non-reactive substance (gutta percha) in the space where the nerve was. The tooth no longer will have a continuous barrier of enamel to protect it. Therefore, it will be restored with either a composite filling or a crown. To reduce pain due to grinding or clenching, the dentist will make a plastic night guard. Use the guard while you sleep.