Toothache After a Crown: Reading the Timeline to Find the Cause
A crown is placed to protect a tooth, so discomfort afterwards feels like a contradiction. It is worth saying at the outset that most post-crown discomfort settles and that a good deal of it is straightforwardly correctable — but "give it time" is only appropriate advice for some of the causes, and the wrong advice for others.
The most useful sorting question is when the pain began.
Days one to fourteen: the tooth is reacting to being prepared
Preparing a tooth for a crown means cutting away a layer of enamel and dentine all round. That opens an enormous number of dentine tubules — microscopic fluid-filled channels running from the outer surface towards the pulp.
Two things follow. First, fluid movement within those tubules, triggered by temperature change, pressure or drying air, mechanically deforms nerve endings at the pulp end. This is the hydrodynamic mechanism, and it is why a freshly prepared tooth is sensitive to cold. Second, the cutting itself, and the heat generated, produces a degree of inflammation in the pulp.
Short, sharp sensitivity to cold that stops as soon as the stimulus is removed is the expected pattern, and it usually declines over days to a few weeks as the pulp lays down reparative dentine and the tubules become less permeable. Cement can also cause a transient chemical irritation, particularly where the remaining dentine layer over the pulp is thin.
Our article on getting used to a new dental crown covers the normal settling period.
What is not expected in this period: pain on biting. That points to something mechanical.
Any time after fitting: the crown is high
This is the most common correctable cause, and the one most often endured unnecessarily.
The periodontal ligament detects loading with remarkable precision — a discrepancy of a fraction of a millimetre is enough to be registered. If the crown contacts before the other teeth, that tooth absorbs a disproportionate share of every closure, several hundred times a day. The ligament becomes inflamed, and the tooth develops a dull ache, tenderness to biting, and often a sense that it feels taller than its neighbours.
Two things make this harder to detect than it should be. The local anaesthetic used during fitting means the bite is checked while proprioception is impaired, so a discrepancy can be missed. And the ache builds over a day or two rather than appearing immediately, so patients often do not connect it to the appointment.
It is corrected in a few minutes with a bite adjustment, and relief is usually rapid. Our article on occlusal adjustment and bite harmony and our article on managing functional occlusion in full-coverage restorations cover the principles. Our article on pain on biting generally covers how the cause is narrowed down.
A related but distinct problem is a contact that is fine in straight closure but interferes when the jaw moves sideways. This produces discomfort during chewing rather than on simple biting, and is checked separately.
Weeks two to twelve: the pulp may not be recovering
Where sensitivity is not improving after a few weeks, or has changed character, the pulp itself may be the issue.
The signs that inflammation has become irreversible are fairly specific: pain that lingers for many seconds or minutes after a cold or hot stimulus rather than stopping immediately; pain arising spontaneously with no trigger; pain that wakes you at night; and pain that is poorly localised, so you can identify the region but not the tooth.
A proportion of teeth require root canal treatment after being crowned. The proportion is higher where the tooth had a large existing restoration, deep decay, or a history of symptoms before the crown — which is often precisely why it needed a crown in the first place. The crown did not create the problem; the tooth was already compromised, and the preparation was an additional insult on top.
Root canal treatment can usually be carried out through the crown without removing it, with the access hole then restored. Our article on root canal treatment through an existing crown covers this, and our article on irreversible pulpitis covers the presentation.
Weeks to months: the gum, not the tooth
Discomfort that is a soreness around the crown rather than within the tooth, with bleeding when brushing or flossing, points to the tissues rather than the pulp.
The usual explanations are a crown margin placed too far beneath the gum, encroaching on the attachment zone that the body maintains between bone and gum; an overhanging margin or excess cement trapping plaque; or contours that are too bulky for the area to be cleaned. Our article on biological width and dental crowns, our article on margin placement and healthy gum tissue and our article on poorly designed crowns causing gum inflammation cover these.
Retained cement is worth singling out, because it is common, easily missed and readily resolved once identified.
Months to years: leakage, decay, or a crack
Cement failure and microleakage. The cement seal at the margin can break down over years, allowing bacteria beneath the crown. The tooth becomes sensitive again, sometimes with a bad taste, and the crown may feel slightly loose or click. Our article on the internal fit of crowns and cement washout and our article on how marginal fit affects long-term tooth health cover this.
Decay at the margin. A crown does not prevent decay; the junction between crown and tooth remains vulnerable, and in a crowned tooth it usually sits at or below the gum where it is harder to clean and harder to see. Recurrent decay beneath a crown is one of the commonest reasons crowns are replaced. Our article on whether old crowns cause a grey line at the gums covers a related appearance change.
A crack in the underlying tooth or root. A root-treated, crowned tooth that develops a deep narrow pocket on one side, tenderness to lateral pressure, and a recurring gum boil is a classic presentation of a vertical root fracture — and it is the main reason such teeth are eventually lost.
A loose crown. Pain with movement, sensitivity to cold reaching the tooth beneath, and often a taste. Our article on emergency care for a broken or loose crown covers what to do.
What to do in the meantime
• Avoid extremes of temperature and very hard or sticky foods on that side
• Use a toothpaste for sensitive teeth, applied along the gum margin and left rather than rinsed away immediately
• Clean around the crown thoroughly, including between the teeth — inflamed gum around a crown usually needs more cleaning, not less
• Analgesia per packet instructions; never place a tablet against the gum
• If you grind, mention it, as a night guard may be relevant
When to arrange an appointment rather than wait
• Pain on biting at any point after fitting
• Sensitivity that is worsening rather than settling after two to three weeks
• Pain lingering well after a hot or cold stimulus
• Spontaneous pain, or pain waking you at night
• Swelling, a gum boil, a bad taste, or fever
• The crown feeling loose, moving, or clicking
• Persistent bleeding or soreness of the gum around the crown
Facial swelling, fever or difficulty swallowing require urgent care.
Key points
• Short cold sensitivity in the first weeks reflects open dentine tubules and usually settles.
• Pain on biting at any stage suggests the crown is contacting too heavily and is corrected in minutes.
• Local anaesthetic during fitting makes a high contact easy to miss, so report it rather than waiting.
• Lingering, spontaneous or night-time pain suggests the pulp will not recover and root canal treatment may be needed.
• Soreness and bleeding of the gum point to margin position, contours or retained cement.
• Late-onset pain suggests cement failure, decay at the margin, or a crack in the underlying tooth.
Frequently Asked Questions
How long should a new crown be sensitive?
Short, sharp sensitivity to cold commonly persists for days to a few weeks and should decline steadily. Sensitivity that worsens, or that lingers after the stimulus is removed, should be checked.
My crown hurts when I bite. Will it settle?
Not usually. Pain specifically on biting suggests the crown is contacting before the other teeth. A short adjustment appointment generally relieves it quickly, and waiting simply prolongs the inflammation.
Can a crowned tooth still need a root canal?
Yes. Preparation is an additional insult to a pulp that was often already compromised, and a proportion of crowned teeth subsequently need root canal treatment. It can usually be carried out through the crown.
Why do my gums hurt around the crown?
Commonly because the margin sits too deep, the contours are bulky, or cement was retained at fitting. All are identifiable at an examination and addressable.
My crown is years old and has started hurting. Why now?
Frequently cement breakdown allowing leakage, decay at the margin, or a crack in the tooth beneath. Radiographs are usually needed, as the relevant area sits under the crown.
Can a tooth under a crown decay?
Yes. The crown itself does not decay, but the junction between crown and tooth remains susceptible, and in crowned teeth that junction often sits at or below the gum line.
Next Steps
Discomfort after a crown is usually identifiable and often quickly correctable, and pain on biting in particular is not something to endure. You can contact our team to arrange a review, or read more about dental crowns and root canal treatment.
Dental Disclaimer
This article is provided for general information only and does not constitute dental advice. The cause of discomfort in a crowned tooth can only be determined through clinical examination and radiographs, and outcomes vary between individuals. If you develop facial swelling, fever or difficulty swallowing, seek urgent care.
Next review due: 13 August 2027
Written by Dr Elisabeth Lichtmannegger · reviewed by Dr Elisabeth Lichtmannegger, GDC 319325
This article is general information, not personal clinical advice. For a diagnosis and a plan tailored to you, book a consultation with a GDC-registered dentist.
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