Why are my teeth sensitive, and how is tooth sensitivity treated?

That sudden, sharp twinge when you drink cold water, bite into ice cream or breathe in cold air is one of the most common reasons people visit a dentist. In most cases tooth sensitivity happens because dentine, the softer layer under the enamel, has become exposed. Dentine contains thousands of tiny tubes that lead towards the nerve, so cold, heat, sweet or sour foods can trigger a quick flash of pain.

The good news is that ordinary sensitivity is usually manageable. The important part is telling the difference between harmless sensitivity and pain that signals decay, a crack or an inflamed nerve.

What causes tooth sensitivity?

The American Dental Association lists tooth decay, fractured teeth, worn fillings, gum disease, worn enamel and exposed roots as common causes (ADA MouthHealthy: sensitive teeth). This table explains how each one typically feels:

Why are my teeth sensitive to cold water?

Cold is the most common trigger because it makes the fluid inside the dentine tubes move quickly, which the nerve senses as a sharp pain. If the pain lasts only a few seconds after the cold is gone, it usually comes from exposed dentine. If it lingers for more than about 30 seconds, or you have to stop eating on that side, the nerve itself may be inflamed and the tooth should be checked soon.

Sensitivity after a filling, whitening or cleaning

Sensitivity after a filling

It is common for a newly filled tooth to be sensitive to cold or to biting for a few days to a few weeks, especially after a deep filling. It should get steadily better. See your dentist if it is getting worse, if the tooth hurts when you bite down (the filling may be slightly high), or if you develop throbbing or night pain. A filling that is high on the bite is a quick adjustment.

Sensitivity after whitening

Whitening gels can cause temporary sensitivity during treatment and for a short time afterwards. Spacing out sessions and using a sensitive toothpaste usually helps. Our page is teeth whitening safe? covers this in more detail.

Sensitivity after scaling

Root surfaces that were covered by tartar are suddenly exposed after cleaning. This usually calms down within days to a few weeks as the gums heal. More in teeth scaling and cleaning.

How to treat sensitive teeth at home

1. Use a toothpaste for sensitive teeth twice a day. Products usually contain potassium nitrate, stannous fluoride or arginine. It usually takes several uses, often a few weeks, before you feel a difference, so give it time.
2. Spit, don't rinse after brushing. You can also smear a little toothpaste on the sensitive area before bed.
3. Brush gently with a soft brush and small circular movements; avoid hard scrubbing at the gum line.
4. Reduce acidic drinks and foods such as soft drinks, juices, lemon and vinegar, and don't brush straight after them; wait about an hour.
5. Avoid whitening toothpastes and charcoal powders while your teeth are sensitive.
6. If you grind your teeth, mention it to your dentist; a night guard can protect the enamel.

In-clinic treatments for tooth sensitivity

When home care is not enough, or the cause needs fixing, the dentist can:

• Apply a fluoride varnish or desensitising agent to the exposed areas.
• Cover exposed roots or worn areas with tooth-coloured bonding.
• Replace a leaking or worn filling, or place a crown on a cracked tooth.
• Refer for a gum graft where recession is significant.
• Consider root canal treatment only if severe, persistent sensitivity comes from an inflamed nerve and other measures have not worked.

When tooth sensitivity is a sign of a problem

See a dentist promptly if you notice any of these:

• Pain that lingers long after the hot or cold is gone, or that throbs.
• Pain that starts on its own or wakes you at night (see toothache at night).
• Sharp pain when biting on one tooth.
• Swelling of the gum or face, or a bad taste.
• Sensitivity limited to one tooth that has not improved after two to three weeks of sensitive toothpaste.

These point to decay, a crack or nerve inflammation rather than simple exposed dentine, and they are much easier to treat early.

How Prof. Nouran approaches sensitive teeth

Many patients have spent months switching toothpastes, or avoid cold drinks altogether, without anyone explaining why the teeth are sensitive. At El Nabi Dental Clinic in Maadi, Prof. Nouran first finds the cause: she checks for recession, worn enamel, cracks, leaking fillings and the way your teeth meet when you bite. The aim is the most conservative fix that works, so a sound tooth is not drilled or crowned without a clear reason. You leave knowing what is causing the sensitivity and what your options are.

If one tooth has been bothering you for weeks, send us a message on WhatsApp to arrange a check, or read about what an examination includes on our general dentistry page.