Sensitivity After a Filling: What Is Normal and What Is Not

Removing decay means drilling through enamel and into dentine, which is full of microscopic channels leading to the nerve. Drilling, the cleaning of the cavity, the filling material and the light used to set it all irritate the pulp a little.

The nerve inside the tooth sits in a closed space, so even mild irritation makes it more reactive than usual for a while. The result is a short, sharp response to cold, sweet food, or air, which stops when the trigger is removed. That pattern is a normal healing response, much like the one described on our sensitive teeth page.

Sensitivity is usually at its worst in the first days and fades over a week or two, though a few weeks is not unusual. Cold drinks, sweet food, and a little tenderness when biting hard are all in the normal range. What matters is the direction: it should be getting better, or at least no worse.

While it settles, avoid very cold or hot drinks on that side, and brush with a soft brush and lukewarm water. A toothpaste made for sensitive teeth, containing potassium nitrate, can help if used daily, and rubbing a little on the area is sometimes advised. It can take a couple of weeks of regular use to notice the effect.

If the filling stands slightly proud, the tooth hits first when you close your mouth. The result is a sore tooth on biting, sometimes a dull ache, and it does not settle on its own because it is struck again at every meal. Numbness during the appointment can hide a high spot, so it shows up only afterwards.

Do not wait for it to wear in. The fix is quick. The dentist marks the bite with thin paper, trims the filling down and polishes it, usually in minutes and often without anaesthetic. If your bite feels off, say so rather than getting used to it, because a high filling can strain the tooth and the jaw.

The closer the cavity was to the nerve, the more irritated it is likely to be, and the longer it may take to quieten down. A deep filling can be sensitive for weeks. Sometimes a protective lining is placed under the filling to help.

A larger filling usually means a longer settling time than a small one, simply because more tooth was cut and more of the dentine was exposed. A filling placed in a tooth that was already tender before treatment is more likely to stay sore than one placed in a tooth with no symptoms.

Sometimes the nerve was already inflamed before the filling, and the filling cannot reverse that. This is why a tooth that had a lot of pain before treatment is the one most likely to stay sore. The wider story of how cavities progress is in what a cavity in teeth looks like.

Sensitivity that starts weeks or months after a filling, rather than straight away, deserves a look too. It can mean new decay at the edge, a crack, or a leaking margin, as covered in types of dental fillings.

Be concerned about pain that lingers for a minute or more after a hot or cold drink, pain that comes on with no trigger, an ache that wakes you at night, or sensitivity that is getting worse after the first couple of weeks. Swelling of the gum, a bad taste, or a pimple on the gum are also warning signs.

These point to a pulp that is inflamed beyond recovery, or one that has died. The tooth then needs a root canal, as set out in filling or root canal, and the sooner it is seen the simpler it is. Swelling that spreads across the face, fever, or difficulty swallowing or breathing needs same-day care.

For ordinary sensitivity, give it time, use a desensitising toothpaste and avoid extremes of temperature. If it is not improving after a few weeks, if the bite feels high, or if any warning sign appears, contact the clinic. Painkillers such as paracetamol or ibuprofen as directed on the label are fine for short use, with the usual cautions. The process is on the tooth fillings page.

Mention the sensitivity at your next check-up even if it has gone. It helps the dentist judge how that tooth responded, and whether it should be watched.