Diagnosis before anything else
We test the nerve of the tooth, probe the gum around it, check the bite and take an X-ray. Which one of the six causes is at work determines everything that follows.
About this treatmentDental condition · Wimpole Street, Marylebone
Gum pain around one tooth: working out which of several causes is responsible
When the gum hurts everywhere, the cause is usually general: gingivitis, a new toothpaste, a viral infection. When it hurts around a single tooth, something local is going on, and the list of possibilities is surprisingly long. A shred of food wedged below the gum, a periodontal pocket that has become infected, a dying nerve tracking pus out through the gum, a partly erupted wisdom tooth, a cracked root, or simply a rough filling edge irritating the tissue every time you eat. Some of these settle with a floss and a salt rinse; others are the early stage of an abscess that will not resolve on its own. The distinction can be difficult to make at home, and the symptoms overlap. Our Wimpole Street dentists approach it methodically: where exactly it hurts, what makes it worse, what the tooth itself says when tested, and what the X-ray shows beneath the gum.
Recognising it
How it usually feels
A tender, swollen patch of gum beside one tooth
Localised inflammation, often from a trapped foreign body or an infected pocket.
Pain that started after a meal with meat, popcorn or seeds
Something has lodged between tooth and gum and is being pressed deeper.
A small blister or boil on the gum that comes and goes
A sinus tract draining infection from the root or from a deep pocket.
The tooth itself feels high or sore to bite on
Inflammation at the root tip lifting the tooth in its socket.
Soreness behind the last molar, sometimes with difficulty opening
Infection under the gum flap over a wisdom tooth.
Behind the symptoms
What's going on
- 01
Food impaction
A fibrous strand of meat or a seed husk forced between two teeth and into the gum acts like a splinter. The gum swells, throbs and bleeds within a day. It is the commonest cause and the easiest to resolve, but if the gap traps food repeatedly the contact between the teeth needs correcting.
- 02
Periodontal abscess
In someone with gum disease, a deep pocket can become blocked so that pus accumulates rather than draining. The gum over the pocket balloons and is exquisitely tender, and the tooth may loosen. The nerve inside is usually alive, which distinguishes it from an abscess of the tooth.
- 03
Infection from a dead nerve
When decay or a crack kills the nerve, bacteria escape from the root tip into the bone and pus finds its way to the surface through the gum, which becomes sore and may develop a boil. The tooth typically does not respond to cold and hurts on tapping.
- 04
Pericoronitis around a wisdom tooth
A partly erupted lower wisdom tooth sits under a flap of gum that traps food and bacteria. The flap becomes swollen and painful, the opposite tooth bites on it, and the infection can spread into the cheek or throat if not treated.
- 05
A cracked or fractured root
A vertical crack running down a root, often in a tooth that has had a root canal and a post, lets bacteria along its length. The gum beside it develops a narrow, deep pocket and a persistent, low-grade soreness that antibiotics do not touch.
Before your appointment
What you can do today
- Floss gently around the painful tooth, or use an interdental brush, to dislodge anything trapped; a water flosser can help if you have one.
- Rinse with warm salt water three or four times daily to keep the area clean and reduce swelling.
- Take pain relief as directed on the pack; anti-inflammatories tend to help gum pain more than paracetamol alone.
- Do not press, pick at or lance a swollen gum, and do not use leftover antibiotics.
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
Clearing and cleaning the pocket
Trapped debris is removed and an infected pocket is irrigated and thoroughly cleaned under local anaesthetic, which usually relieves the pain within hours.
About this treatmentRoot canal treatment
If the nerve has died and is the source of the infection, the canals are cleaned, disinfected and sealed so the gum can heal from within.
About this treatmentAdjusting or replacing a restoration
An overhanging edge is trimmed and polished, or a poorly fitting filling or crown is replaced so that the gum is no longer traumatised.
About this treatmentWisdom tooth care
The flap is cleaned and irrigated, and if episodes recur or the tooth cannot fully erupt, removing it ends the problem.
About this treatmentExtraction where the root is cracked
A vertically fractured root cannot be repaired. Removing the tooth clears the infection, and the replacement options are planned once the site has healed.
About this treatmentFees
Costs to expect
An emergency or problem-focused appointment at Wimpole Street, including X-rays and immediate relief such as removing debris or cleaning a pocket, is expected to be around £95. Where gum disease underlies the problem, periodontal treatment from £850 is planned afterwards.
If the tooth’s nerve is the source, root canal treatment is indicative at £695 for a front tooth and £895 for a molar. Replacing a faulty filling is from £185, wisdom tooth removal from £250, with surgical cases higher, and extraction of a fractured tooth from £250 with replacement quoted separately. You receive the diagnosis and the options in writing before committing to anything beyond the first visit.
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
- Gum pain beside one tooth has lasted more than three days.
- There is visible swelling, a boil or pus at the gum.
- The tooth hurts to bite on or feels loose.
- Flossing has not shifted whatever is trapped.
- You have difficulty opening your mouth or swallowing comfortably.
FAQ
Common questions
Gum problems tend to hurt on pressure and touch, bleed easily, and the tooth still feels cold normally. Nerve problems tend to give a tooth that is dead to cold, sore to tap and sometimes discoloured, with the gum boil sitting further up towards the root tip. In practice the two overlap and the tests we run in the surgery settle it.
Usually because the contact between two teeth has opened up, either from a worn or broken filling, a tooth that has drifted, or gum recession creating a space below the contact. Correcting the contact, often by reshaping or replacing a filling, stops the trap. Until then, keep an interdental brush handy.
The pressure has been released, which is why it feels better, but the infection producing the pus is still there and the boil will refill. Whether the source is a pocket or a dead nerve, it needs treating; a draining sinus that is left alone slowly destroys bone around the tooth.
A single sore site does not mean generalised periodontitis, but a periodontal abscess only forms where there is already a deep pocket, so it is a prompt to have the whole mouth measured. If other pockets are found, treating them early prevents further episodes.
Most localised gum infections resolve once the cause is removed and the area is cleaned, without antibiotics. They are reserved for spreading swelling, fever or patients whose immune system is compromised, and always alongside treatment of the source rather than instead of it.
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.
Related conditions
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
