Broken Tooth With Swelling: Your Guide to Urgent Dental Care
Pain from a broken tooth is unpleasant but usually contained. Swelling means something has changed.
Once the face or gum begins to swell, bacteria are no longer confined to the tooth. They have reached the tissue beyond it, and the body is responding. That response is what causes the swelling, and it is why the situation now needs treating with urgency rather than patience.
The great majority of cases are dealt with without drama, provided they are seen promptly. A small number are genuinely serious, and it is worth knowing which signs put you in that group.
Why Does a Broken Tooth Cause Swelling?
What is the mechanism?
When a fracture breaks through enamel and dentine, bacteria gain access to the pulp — the living tissue inside the tooth. The pulp becomes inflamed and, in a rigid chamber with a restricted blood supply, often dies. Bacteria then multiply within the empty root canal system and pass out through the opening at the root tip into the surrounding bone. The immune system responds, pus accumulates, and pressure builds. That collection is a dental abscess, and the swelling you can see or feel is the tissue response around it.
Infection through exposed pulp
The most direct route. A fracture reaching the pulp allows immediate bacterial contamination, as covered in our article on fractures exposing the nerve.
Abscess formation
Bacteria reaching the tissue at the root tip produce a collection of pus. This can remain localised, producing a tender lump on the gum, or spread through the tissue planes of the face.
Traumatic inflammation
Swelling immediately after an injury can be inflammatory rather than infective — a response to the impact itself. This typically appears within hours and begins improving after two or three days. Swelling that appears days later, or that worsens after day three, is more likely to be infection.
Pre-existing infection
Sometimes the tooth was already infected — from decay, a failing restoration or a previous root treatment — and the fracture simply exposed a problem that was already there.
The Infection Process
Bacteria that reach the pulp meet a tissue with very limited capacity to defend itself. The blood supply enters through a narrow opening at the root tip, and the pulp is enclosed in unyielding dentine, so it cannot swell in response to inflammation. Pressure rises instead, blood flow is compromised, and the tissue dies.
The dead root canal system then becomes a protected reservoir. Bacteria there are largely beyond the reach of the immune system and of antibiotics carried in the blood, which is a critical point: antibiotics alone do not resolve a dental abscess. They can control spreading infection temporarily, but the source must be dealt with by draining the abscess and either treating or removing the tooth.
From the root tip, infection spreads into bone, producing the bone changes visible on radiographs and described in our article on apical periodontitis and infection spreading to the jawbone. From there it can track through the tissue planes of the face and neck, which is where the serious complications arise.
Localised gum swelling
A tender lump on the gum near the affected tooth, sometimes with a small opening discharging pus. This often relieves pain temporarily, which people misinterpret as improvement — the infection is still present. Our article on bad taste from a ruptured abscess explains this pattern.
Facial swelling
Swelling of the cheek, jaw, under the chin or around the eye. This indicates the infection has spread beyond the immediate area and needs same-day assessment.
Accompanying symptoms
• Severe, throbbing toothache, often worse at night
• Pain when biting or when the tooth is touched
• A persistent bad taste or smell
• Fever, chills or feeling generally unwell
• Tender, enlarged lymph nodes under the jaw
Seek immediate emergency care — hospital rather than a dental appointment — if you have:
• Difficulty swallowing, or a feeling that the throat is closing
• Difficulty breathing
• Swelling spreading towards the eye or down the neck
• Inability to open your mouth more than a small amount
• A rapidly enlarging swelling
• High fever with confusion or feeling very unwell
These indicate infection spreading through the tissue spaces of the face and neck, which can compromise the airway. This is uncommon but is a genuine medical emergency.
Managing Symptoms Before Your Appointment
• Pain and inflammation: over-the-counter analgesia following the packet instructions, if suitable for you. Never place aspirin against the gum
• Cold compress against the outside of the face, twenty minutes on and twenty off, not applied directly to skin
• Warm salt-water rinses, gently, several times a day
• Keep the area clean — continue brushing gently despite the discomfort, as plaque accumulation makes things worse
• Sleep with your head elevated, which reduces throbbing
• Stay hydrated and eat soft food
• Avoid applying heat to the outside of the face, squeezing or attempting to drain the swelling yourself, and using leftover antibiotics from a previous course
Squeezing a swelling can force infection deeper into the tissues and is genuinely dangerous. Leave it alone.
Treatment Approaches
Drainage. The priority. Pus is drained, either through the tooth, through an incision in the gum, or by removing the tooth. Relieving the pressure is what resolves the pain and stops the spread.
Antibiotics. Prescribed where infection is spreading, where there is systemic involvement, or where the patient is medically compromised. They are an adjunct, not a treatment in themselves, and prescribing is guided by antimicrobial stewardship. Do not expect antibiotics as a matter of course.
Root canal treatment. Where the tooth is restorable, the infected canal system is cleaned, disinfected and sealed, removing the reservoir of bacteria.
Extraction. Where the tooth cannot be restored — a fracture below the gum, a split root, or too little structure remaining. Replacement options such as a dental implant or bridge are considered once the infection has settled.
Definitive restoration. After the infection is controlled, the tooth is restored, often with a dental crown since a root-treated posterior tooth is more prone to fracture.
Hospital referral. For severe or spreading infection, which may require drainage under general anaesthetic and intravenous antibiotics.
When Professional Dental Assessment May Be Needed
Contact an emergency dentist the same day if you have:
• Any facial or jaw swelling
• A dental abscess or a lump on the gum
• A broken tooth with pain or swelling
• Fever alongside dental pain
• A persistent bad taste or discharge
• Swollen gums around a damaged tooth
Go to hospital immediately for difficulty swallowing or breathing, swelling spreading to the eye or neck, or inability to open your mouth.
Reducing the Risk
• Treat broken teeth promptly rather than waiting for symptoms
• Do not ignore a tooth that hurt and then stopped — the pulp may have died
• Wear a night guard if you grind and a mouthguard for sport
• Attend routine check-ups with radiographs at the recommended interval
• Attend hygiene appointments
• Clean between the teeth daily
• Report a cracked tooth or a failing filling early
Key Points to Remember
• Swelling means infection has moved beyond the tooth
• Antibiotics alone do not resolve a dental abscess; drainage and definitive treatment are needed
• A discharging gum lump relieves pain but does not mean the infection has gone
• Swelling worsening after day three following trauma suggests infection rather than bruising
• Never squeeze a swelling or apply heat to the face
• Difficulty swallowing or breathing is a medical emergency needing hospital care
• Do not use leftover antibiotics from a previous course
The NHS page on dental abscess explains symptoms, treatment and when to seek urgent help.
Frequently Asked Questions
1. Is a broken tooth with swelling an emergency?
Yes, it should be treated as urgent. Swelling indicates infection has spread beyond the tooth into the surrounding tissue. Arrange same-day dental care. If you have difficulty swallowing or breathing, swelling spreading towards the eye or down the neck, or you cannot open your mouth properly, go to hospital immediately.
2. Will antibiotics clear the infection?
Not on their own. The source of the infection is inside the tooth, in a dead root canal system with no blood supply, so antibiotics carried in the blood cannot reach it effectively. They may control spreading infection temporarily, but definitive treatment — drainage plus root canal treatment or extraction — is what resolves it.
3. The swelling burst and the pain went — is it over?
No. Spontaneous drainage relieves pressure and therefore pain, which feels like recovery, but the source of infection inside the tooth remains. The abscess commonly recurs, and infection continues to affect the surrounding bone in the meantime. It still needs proper treatment.
4. How long can I wait to be seen?
Not long. Dental infections can progress quickly, sometimes over hours. Arrange same-day care for any facial swelling. Where there is difficulty swallowing or breathing, or rapidly worsening swelling, seek immediate emergency medical attention rather than waiting for a dental appointment.
5. Can I put a hot compress on the swelling?
No. Heat applied to the outside of the face can encourage infection to spread through the tissues. A cold compress against the outside of the cheek is safer for comfort and swelling. Warm salt-water rinses inside the mouth are fine and are helpful for keeping the area clean.
6. Will the tooth have to be taken out?
Not necessarily. Many teeth with abscesses can be saved with root canal treatment, provided enough sound structure remains and the root is intact. Extraction is recommended where the tooth is fractured below the gum, the root is split, or too little structure remains to restore it. Your dentist will explain the options with a written estimate.
Conclusion
Swelling is the point at which a broken tooth stops being something to deal with next week.
Most cases are resolved straightforwardly once someone drains the infection and treats the source. The problem only becomes serious when it is left, and the signs that it is being left too long — difficulty swallowing, swelling spreading, being unable to open your mouth — are the ones to act on immediately.
For urgent dental care, book an appointment at 22 Wimpole St, London W1G 8GQ, or call 020 7183 0692.
Dental symptoms and treatment options should always be assessed individually during a clinical examination.
Dental Disclaimer
This article is for general educational information only and is not professional dental advice, diagnosis, or a treatment recommendation. Information here is general and cannot replace an in-person assessment by a qualified, GDC-registered dental professional. Symptoms, suitability, fees, timelines, and outcomes vary according to individual clinical circumstances. If you have pain, swelling, or other concerning symptoms, seek prompt professional dental care. Always request a written treatment plan and cost estimate before proceeding with treatment.
Written Date: 25 August 2026 Next Review Date: 25 August 2027
Written by Dr Ayman Mukhtar · reviewed by Dr Ayman Mukhtar, GDC 302583
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.
