Urgent assessment and drainage
The tooth is tested and X-rayed to confirm the source. Draining the pus, through the tooth or via a small incision in the gum, relieves pressure and pain quickly, often the same visit.
About this treatmentDental condition · Wimpole Street, Marylebone
Dental abscess: recognising it, and why the tooth itself must be treated
An abscess is the body walling off a bacterial infection with a pocket of pus. In the mouth that pocket sits either at the tip of a tooth root, when the nerve inside has died, or in the gum beside a tooth, when a deep periodontal pocket has become infected. Pressure builds inside bone, which is why the pain is so often described as throbbing and relentless. Two points matter above all others. First, antibiotics can calm the infection for a while but cannot reach a dead nerve or clean out a pocket, so the abscess returns unless the source is treated. Second, infection that spreads into the face or neck can become a medical emergency within hours. Our Wimpole Street team treats the cause: draining the abscess, saving the tooth with root canal treatment where possible, or removing it where not.
Recognising it
How it usually feels
Deep, throbbing ache that keeps time with your pulse
Pressure from pus inside bone with nowhere to go.
A tooth that feels taller and hurts to tap or bite on
Inflammation at the root tip lifts the tooth fractionally in its socket.
Swelling of the gum, cheek or under the jaw
Pus tracking through bone into soft tissue; may be firm or soft.
A small pimple on the gum that bursts and refills
A sinus tract draining the abscess; pain often eases when it drains.
Foul taste or smell
Pus leaking into the mouth.
Fever, tender glands in the neck, feeling generally unwell
Signs the infection is affecting the body, not just the tooth.
Behind the symptoms
What's going on
- 01
Deep decay reaching the nerve
Once bacteria breach the enamel and dentine and enter the pulp, the nerve becomes inflamed and then dies. Bacteria colonise the empty canal and escape through the root tip into bone, where the abscess forms. This is the commonest route.
- 02
A crack or fracture
A cracked tooth offers bacteria a direct path to the pulp even when there is no visible cavity. The tooth may have caused intermittent biting pain for months before the nerve finally dies and an abscess develops.
- 03
Trauma years earlier
A knock to a front tooth can damage its blood supply so that the nerve dies slowly and silently. The abscess may appear years later, often with the tooth having darkened in the meantime.
- 04
Advanced gum disease
In periodontitis, deep pockets between gum and root fill with bacteria. If the opening becomes blocked, or the body’s defences drop, pus accumulates and a periodontal abscess forms alongside the tooth rather than at its tip.
- 05
Failing restorations or earlier root treatment
Leaking crowns and fillings allow bacteria back into a tooth. A previously root-treated tooth can also re-infect if the seal fails or a canal was missed, producing a new abscess on an old problem.
- 06
Partially erupted wisdom teeth
A flap of gum over a wisdom tooth traps food and bacteria. Recurrent infection there (pericoronitis) can progress to a true abscess and spread towards the throat, which is why swelling in that area is watched closely.
Before your appointment
What you can do today
- Take pain relief as directed on the pack; a pharmacist can advise on combining paracetamol and ibuprofen if you are able to take both.
- Rinse gently with warm salt water several times a day; if a gum boil bursts, this helps keep the area clean.
- Sleep with your head raised on an extra pillow, which reduces the throbbing.
- Avoid heat on the face, hard chewing on that side, and very hot or cold drinks.
- Do not attempt to lance the swelling yourself, and do not take leftover antibiotics from a previous course.
- If swelling starts to spread towards the eye or down the neck, or swallowing becomes difficult, stop waiting for a dental appointment and go to A&E.
These are holding measures, not a substitute for an examination. Use any pain relief exactly as directed on the pack and check with a pharmacist if you take other medicines.
In the chair
How we treat it at Wimpole Street
Root canal treatment
Where the tooth is worth saving, the dead nerve tissue and bacteria are cleaned out of the canals, which are then disinfected and sealed. Usually one or two visits, followed by a crown to protect the tooth.
About this treatmentExtraction
If the tooth is fractured through the root, has lost too much bone or cannot be predictably root-treated, removing it removes the infection. Replacement with an implant or bridge is discussed once healed.
About this treatmentPeriodontal treatment
For a gum abscess, the pocket is drained and thoroughly cleaned under local anaesthetic, and the underlying gum disease is then treated to stop it recurring.
About this treatmentAntibiotics, when indicated
Prescribed only where there is spreading swelling, fever or a compromised immune system, and always alongside treatment of the tooth. They are not a substitute for drainage.
Crown after root treatment
A root-treated back tooth is brittle. A crown restores its strength and seals the canals against re-infection, and is planned once the abscess has healed.
About this treatmentFees
Costs to expect
An emergency appointment at Wimpole Street, including X-rays and initial drainage or dressing, is expected to be around £95. Root canal treatment is indicative at £695 for a front tooth and £895 for a molar, with a protective crown afterwards from £995.
Extraction, where the tooth cannot be saved, starts from £250, with surgical removal quoted higher. Treatment of a periodontal abscess and the underlying gum disease is planned after the emergency visit and quoted per session. Every option, including its fee and likely prognosis, is written down so you can choose between saving and removing the tooth with clear information.
Figures are indicative prices for Wimpole Street and are confirmed in a written plan once a dentist has examined you. Fees match our South Kensington and St Paul's clinics.
Don't wait if
When to see a dentist
- Throbbing pain in a tooth, especially if it wakes you or is worse lying down.
- A tooth that hurts to bite on or feels raised.
- Any swelling in the gum, cheek, jaw or under the chin.
- A recurring spot on the gum that discharges.
- Fever, swollen neck glands or generally feeling unwell with toothache.
- A tooth that has darkened after an old injury, even without pain.
FAQ
Common questions
Almost certainly not. Pain often eases when the nerve finally dies or when pus finds an exit through the gum, relieving the pressure. The infection remains and will flare again, so this is not a reason to cancel the appointment.
Antibiotics travel in the bloodstream, and a dead nerve has no blood supply, so the bacteria inside the tooth are beyond reach. Antibiotics can shrink the surrounding swelling temporarily, but the abscess refills once the course finishes. Only cleaning out the canal, draining the pocket or removing the tooth removes the source.
Warning signs are swelling that is spreading quickly, that involves the eye or closes it, that extends under the jaw or down the neck, difficulty swallowing your own saliva, trouble breathing, a hoarse voice, or a high fever with rigors. Any of these means 999 or A&E straight away, not a dental appointment.
An infected tooth can be harder to numb, so we take extra care with anaesthetic and sometimes drain and dress the tooth first, returning to finish the treatment once it has settled. Most patients report that the relief from drainage far outweighs any discomfort during treatment.
A large, long-standing abscess can erode bone around adjacent roots and occasionally affect their nerves, but this is uncommon if treated within weeks rather than years. The more usual consequence of delay is losing the affected tooth itself.
For molars and premolars, almost always, because the tooth is hollowed and dries out, making it prone to fracture. Front teeth with enough remaining structure can sometimes be restored with a filling alone. We advise on this once the tooth has been cleaned and we can see how much sound tissue remains.
Marylebone, W1
Wimpole Street opens 1 October 2026
Leave your details and we will be in touch when the Marylebone diary opens. If the problem cannot wait, the same clinicians are already seeing patients in South Kensington and at St Paul's.
Opening 1 October 2026
Wimpole Street is not yet seeing patients. Until then, please book or call our South Kensington clinic on 020 7183 2362 or our St Paul's clinic on 020 7183 3709. Questions about the new clinic: wimpolestreet@md.co.uk.
Until we open
Need an appointment before 1 October 2026?
The same clinical team already works from two other Medical & Dental clinics. Book at either one now and, if you prefer, move your ongoing care to Wimpole Street once the doors open.
South Kensington
- 20 Old Brompton Road, London SW7 3DL
- Open seven days a week
- 020 7183 2362
St Paul's, City of London
- 5 Ave Maria Lane, London EC4M 7AQ
- Open Monday to Friday
- 020 7183 3709
