A tooth abscess is a collection of pus caused by bacterial infection, either inside the tooth or in the gum beside it. It typically causes constant throbbing pain, swelling, and a tooth that is tender to touch. An abscess will not clear up on its own and needs dental treatment. Swelling that spreads to the eye or neck, or affects swallowing or breathing, is a medical emergency.
How an abscess forms
Bacteria reach the inner pulp of a tooth through deep decay, a crack, or a failed filling. The pulp dies, infection spreads out through the tip of the root into the surrounding bone, and pus collects there. That is a periapical abscess.
A periodontal abscess is different - it forms in the gum pocket beside a tooth, usually where gum disease has created a deep pocket that traps bacteria.
What it feels like
- Constant throbbing pain, often severe and often worse lying down
- The tooth feeling raised or tender when you bite
- Swelling in the gum, cheek or jaw
- A bad taste, or a sudden salty discharge if the abscess bursts
- Tender, swollen glands under the jaw or in the neck
- Fever and feeling generally unwell
- The tooth may darken
If it bursts
Sometimes an abscess drains on its own - a sudden foul or salty taste, and the pain drops away sharply. That relief is real but it is not a cure. The source of infection is still there and it will refill. Get it seen.
How it is treated
Treatment drains the infection and deals with its source. Depending on the tooth, that usually means root canal treatment to clean out the inside of the tooth, or extraction where the tooth cannot be saved. A periodontal abscess is treated by cleaning out the gum pocket.
Antibiotics may be prescribed alongside, particularly where infection is spreading, but antibiotics alone do not fix it - the source has to be dealt with.
See a dentist if
- You have any of the symptoms above - an abscess always needs treating
- Swelling is spreading towards your eye or down your neck
- You have a fever, or feel unwell as well as sore
- You cannot open your mouth properly
- Swallowing or breathing is affected - call 111, this is an airway emergency
We're in central Queenstown and keep room for emergencies. Call 03 441 8248.
This page is general information, not a diagnosis. Reviewed by Dr Adrian Paul, BDS (Otago), principal dentist at Lakeside Dental Practice. If you're worried about a specific problem, see a dentist.
