Pain and sensitivity after a filling: how much is normal, and when should it be looked at again?

While a filling is being done, the tooth is put under strain in several different ways. When the decay is cleaned out, the inner layer of the tooth (dentine), full of microscopic tubules running to the nerve, is exposed; the drill produces heat and vibration; and the filling material dries and hardens as it bonds to the tooth. The tooth may respond to this procedure with short-lived sensitivity. Cleveland Clinic writes that mild tooth sensitivity after a filling, and tenderness of the gum in that area, are normal, and that they are temporary and should pass within a week or two.

How common is this? One of the best answers comes from a practice-based study in the USA involving 45 dentists. Composite fillings were placed in teeth with decay on the chewing surface, and patients were asked at weeks 1, 4 and 13 about sensitivity to heat, cold, sweet things, clenching and chewing. At week 4, 18% of the fillings had marked sensitivity. In 63% of teeth that had been sensitive beforehand, the filling had got rid of that sensitivity; on the other hand, in 10% of teeth that had had no sensitivity at all beforehand, new sensitivity had started after the filling. In the early decay in the study, sensitivity was not found to be related to the depth or width of the cavity prepared; this finding cannot be generalised to deep decay close to the nerve.

The effect of the material is not as great as people think. Cochrane's 2026 overview brought together systematic reviews comparing filling materials for back teeth. In the comparison of composite and amalgam, post-filling pain and discomfort had been reported at around 5% in both groups, but the certainty of the evidence was very low. In studies comparing composites filled in a single step (bulk-fill) with composites placed layer by layer, post-filling sensitivity was almost never seen with either method. No clear difference was shown between composite and glass ionomer either. Cochrane's 2021 review comparing amalgam and composite had also seen differences between the groups in some measures, including post-filling sensitivity, but had not found any consistent or clinically important harm.

The first sign that helps you tell them apart at home is what triggers the pain. With pain that appears only when you bite or clench your teeth and barely reacts to heat and cold, a filling left high comes to mind. With fillings done under local anaesthetic, the patient cannot feel the bite correctly; if the filling touches the opposing tooth before the other teeth, that tooth takes too much load with every bite, the connective tissue holding the tooth becomes inflamed and the tooth becomes painful under pressure. A simple check: bring your teeth gently together. If the filled tooth feels as if it touches before the others, or you catch on a single point as you close your mouth, tell your dentist.

The second sign is how long the pain lasts. MSD Manuals writes that with reversible inflammation of the nerve (reversible pulpitis), the pain starts with a trigger and passes within 1–2 seconds of the trigger being removed, whereas with irreversible inflammation the pain lasts for minutes after the trigger is removed or starts on its own. Drink a sip of cold water and count how long the twinge lasts. A twinge that is over in a few seconds and eases over the days fits the normal course. Pain that lasts for minutes after the trigger is removed, gets worse with heat or wakes you at night, on the other hand, suggests that the nerve cannot recover.

With deep fillings the risk is higher. MSD writes that inflammation of the tooth's nerve is associated with decay progressing deep into the dentine and with the tooth undergoing more than one invasive procedure. If the decay has come very close to the nerve, the nerve may already have been under strain before the filling, and the filling cannot always stop this process. If your dentist told you while doing the filling that the decay was close to the nerve, it is worth knowing that persistent pain developing later may not be a fault of the filling but a result of how deep the decay was.

A third possibility is an unnoticed crack in the tooth. A cracked tooth causes a short, sharp pain, especially when biting on a particular point or when releasing the bite. Because a large filling thins the walls of the tooth, a crack may have been there before the filling or may develop afterwards. A 2026 review writes that cracks are hard to detect in the clinic, that diagnosis relies largely on examination under magnification, probing and bite tests, and that metal fillings make imaging harder. If pain on biting continues even though the height of the filling has been corrected, a crack should be looked for separately.

Sometimes the source of the pain is not even the tooth that was filled. Toothache can be referred to neighbouring teeth in the same jaw, and even to the opposite jaw; pain that starts after a filling may in fact coincide with a problem developing in another tooth. The gum can be affected too: the band and wedge used for fillings between teeth can leave the gum tender for a few days, while part of the filling overhanging at the gum margin can cause persistent inflammation in that area. If floss catches or shreds at that point, mention this too.

The first list covers situations that are expected after a filling or are easily resolved. If an item from the second list applies to you, see your dentist without waiting.

The sequence starts with the most dangerous possibility, then moves to the most easily resolved, and from there to the nerve and a crack.

1. 1

   First, a spreading infection is ruled out

   If there is swelling in the face or neck, a fever, or difficulty breathing or swallowing, the assessment is done in A&E; call 112. If these signs are absent, the dental examination goes ahead.

2. 2

   The history of the pain is taken

   You will be asked when the pain started, whether it comes with cold, heat, sweet things or biting, how long it lasts and whether it wakes you at night. Tell your dentist these three things clearly: what sets the pain off, how many seconds it lasts, and whether it is easing or getting worse day by day.

3. 3

   The bite is checked

   Using articulating paper, the dentist checks whether the filled tooth touches before the others and whether it catches in sideways movements. A filling left high is corrected in a few minutes, and the pain often eases within a few days.

4. 4

   The condition of the nerve is tested

   As MSD describes, cold or heat is applied to the tooth, a tapping test is done and, if needed, the vitality of the nerve is checked with an electric test. How long the pain lasts after the trigger is decisive in telling reversible from irreversible inflammation.

5. 5

   An X-ray is taken

   How close the filling is to the nerve, whether there is inflammation at the root tip and whether the filling overhangs between the teeth are assessed. Decay in neighbouring teeth can also be seen at this stage.

6. 6

   A crack is looked for

   If pain on biting continues even though the bite has been corrected, the cusps are tested one by one with a bite stick and the tooth is examined under magnification. If there is a crack, an onlay or crown covering the cusps of the tooth may come up.

7. 7

   The treatment is decided

   With a reversible picture, monitoring or replacing the filling may be enough. MSD writes that with irreversible inflammation, the treatment is root canal treatment and a crown, or extraction.

Treatment varies with the cause of the sensitivity. All of these are procedures your own dentist will carry out; the list below is to help you understand what to expect.

Below are wrong decisions often made in this situation, and what they cost.

Timings vary from person to person and with the depth of the filling. The course below is the usual one; what your dentist tells you takes priority.

1. The first few hours

   Until the numbness wears off, do not eat or have hot drinks; you could bite your cheek or tongue without noticing. Once the numbness has worn off, try biting: if the filled tooth touches first, say so straight away.

2. The first few days

   Mild, short-lived sensitivity to cold and biting, and tenderness of the gum around the filling, are common.

3. The first two weeks

   The sensitivity is expected to ease day by day. Cleveland Clinic writes that these symptoms should pass within a week or two.

4. The following weeks

   In the practice-based study, some of the fillings still had marked sensitivity at week 4. If the sensitivity continues but is easing, mention it at your check-up; if it is getting worse or starts without a trigger, do not wait.

Resolving pain after a filling is a matter for your own dentist; we do not give figures here. The main items that determine the scope of the work are:

What the cause is

Adjusting the bite is a short procedure; replacing the filling, root canal treatment or a crown are much more extensive.

Depth of the filling

With deep fillings close to the nerve, the likelihood of monitoring and additional procedures increases.

Whether there is a crack

If a crack is found, the cusps of the tooth may need to be covered.

Where the filling was done

If the filling is new, the check and adjustment are often done as part of the same dentist's follow-up; it is sensible to ask about this when the filling is done.