A dental abscess is a collection of pus from a bacterial infection, and it will not clear on its own. The good news: with the right treatment, the pain settles quickly and the tooth can often be saved. At Dentist Pymble, we see abscess patients the same day whenever we can, because leaving an abscess to “wait and see” almost always makes it worse. This page covers what an abscess actually is, how the dentist treats it, and the clear signs that mean you should go straight to hospital rather than waiting for a dental appointment.

What is a dental abscess?

A dental abscess is a pocket of pus that forms when bacteria get into a part of the tooth or gum that is normally sealed off. There are two main types. A periapical abscess forms at the tip of the root and starts from decay that has reached the nerve of the tooth. A periodontal abscess forms in the gum alongside the root and starts from advanced gum disease or a trapped food particle.

Both feel similar from the outside: a throbbing tooth, often tender to bite on, sometimes with a small pimple on the gum that leaks salty fluid when pressed. The pain can come and go, which often tricks people into thinking it has healed. It has not — the underlying infection is still there, and it tends to flare up at the worst possible moment.

What causes a tooth or gum abscess?

A periapical abscess starts with tooth decay. Bacteria in plaque eat through enamel, then dentine, then reach the soft pulp inside the tooth. Once the pulp is infected, the infection tracks down the root canal and exits at the tip into the surrounding bone, where the body walls it off into a pocket of pus. Untreated cracks, large failing fillings, and trauma that kills the nerve can all start the same chain.

A periodontal abscess usually starts when bacteria build up in a deep gum pocket that has formed because of advanced gum disease. Food packing into the pocket, or a small piece of shell or seed, can then trigger an acute infection. Both types share the same root cause: bacteria getting somewhere they should not be.

Is a dental abscess a dental emergency?

Yes. An abscess is not something to monitor at home. The infection is sitting next to bone and has access to the bloodstream, and in some cases it can spread quickly into the face, the airway, or the chest. If you have an abscess and any of the signs in the hospital section below, head to emergency immediately. Otherwise, the emergency dentist at our Pymble practice will drain the infection, control the pain, and start the right course of treatment the same day.

How is a dental abscess treated?

Treatment depends on the source. For a periapical abscess, the priority is to remove the infected nerve and drain the pus. This is done with root canal therapy at our Pymble practice: the tooth is opened, the pulp chamber and root canals are cleaned, the abscess is drained through the tooth or through a small incision in the gum, and the canals are sealed. Most teeth that have had a root canal for an abscess also need a crown to prevent fracture.

For a periodontal abscess, the gum is numbed, the pocket is gently cleaned, and the pus is drained. Sometimes the tooth also needs a small procedure to reshape the root surface so the pocket can heal. If the infection is advanced and the tooth has lost too much bone support, extraction may be the most predictable option — and an implant or bridge can be planned once the site has healed.

Antibiotics are sometimes prescribed as an adjunct, but only when the infection is spreading or the patient is at higher medical risk. They do not replace the dental treatment; they buy time until it can be done.

Can an abscess go away with antibiotics alone?

No. This is one of the most common misconceptions in dentistry. Antibiotics can settle the swelling and the pain, sometimes within a day, but they cannot reach the bacteria hiding inside the necrotic nerve or inside a deep gum pocket. As soon as the antibiotic course finishes, the infection tends to flare back up. The only way to truly resolve a dental abscess is to treat the source — root canal, extraction, or deep cleaning of the gum pocket.

This is also why we will not prescribe antibiotics over the phone without seeing you. The right antibiotic, the right dose, and the right duration matter, and you still need a plan for the tooth itself.

When should I go to hospital for a dental abscess?

Go to your nearest emergency department if you have any of the following:

• Swelling that has spread into your face, neck, or under your tongue
• Difficulty opening your mouth, swallowing, or breathing
• A high fever, chills, or feeling generally unwell
• Swelling that is closing one eye
• A compromised immune system (diabetes, chemotherapy, immunosuppression)

These are signs the infection is moving beyond the tooth and into the surrounding tissues. Hospital can give you IV antibiotics, secure the airway if needed, and arrange urgent dental treatment under general anaesthetic if the source tooth cannot be managed in the chair.

How can I prevent another abscess?

Prevention is mostly the unglamorous basics done consistently. Twice-a-day brushing with fluoride toothpaste, flossing daily, limiting sugary drinks and snacks between meals, and seeing the dentist every six months for a check-up and clean. Decay caught early is a small filling. Decay ignored is an abscess. If a tooth has been cracked or heavily filled, talk to your dentist about a crown before the nerve dies. If you have a history of gum disease, stick to the maintenance schedule your dentist recommends, and call early if a pocket flares up.

If you are in Pymble or the surrounding Ku-ring-gai area — Gordon, Turramurra, Wahroonga, Killara — and you suspect an abscess, call our practice. We see neighbouring Gordon patients and other nearby residents for same-day emergency appointments whenever the schedule allows.

Frequently asked questions

What does a dental abscess feel like? A constant, throbbing ache in the tooth or gum, often worse when lying down or biting on the tooth. The gum may be swollen and tender, and you might notice a small pimple on the gum that leaks when pressed. Some patients also have a bad taste in their mouth or a low fever.

Can a dental abscess go away on its own? No. The pain may ease as the abscess drains or the nerve dies, but the source of the infection is still there. Without dental treatment, the abscess will flare again, often worse.

Is a dental abscess contagious? No. The bacteria causing a dental abscess are typically the patient’s own oral bacteria that have moved into the wrong place, not a bug passed between people. You won’t give anyone an abscess by being near them.

How much does abscess treatment cost in Pymble? The cost depends on the source of the infection and the treatment chosen. A root canal and crown is a different investment to an extraction. We will always provide a written quote and a health-fund check before any treatment starts.

Can I take ibuprofen for a dental abscess while I wait for my appointment? Yes, ibuprofen (or paracetamol if ibuprofen is not suitable) is appropriate for the pain. Avoid aspirin placed directly on the gum, as it can burn the tissue. Antibiotics need to be prescribed, not self-started.