A lot of people with a throbbing, infected tooth ring a dental clinic hoping for a script and a few days' rest. Antibiotics can be useful when an infection is spreading or making you unwell, but they cannot reach the source of a tooth infection, which sits inside the dead pulp of the tooth or in a pocket of pus at the root tip. The tooth has to be treated directly, and for many localised infections that treatment is all that is needed.
Where the infection lives
Most tooth infections start when decay, a crack or an old deep filling lets bacteria into the pulp, the soft tissue in the centre of the tooth. The pulp dies, and bacteria multiply in the space that is left, which has no blood supply. Eventually the infection leaks out of the root tip into the bone and can form an abscess.
Antibiotics travel in the blood, so they reach the healthy tissues around an infection reasonably well. They do a poor job of reaching a dead pulp or the inside of a collection of pus. That is why a course of tablets can calm swelling for a while, only for the pain to come back weeks later. The bacteria inside the tooth were never touched.
What the research shows
A Cochrane review updated in 2024 (Cope and colleagues, Cochrane Database of Systematic Reviews) looked at trials in adults with acute tooth infections who were also having dental treatment and pain relief. Adding antibiotics made no clear difference to pain or swelling, although the review included only three small trials and the certainty of the evidence was low to very low. The review found no trials testing antibiotics without dental treatment against a placebo.
Put simply, the evidence that antibiotics add much for a localised infection is weak, while their side effects and their contribution to resistance are well known. That is why Australian dentists use them selectively.
The treatments that clear the infection
Depending on the tooth and how much of it can be saved, the dentist will usually do one of three things:
- Drain the abscess, either through the tooth or through a small cut in the gum, which often brings quick relief from pressure.
- Start root canal treatment, removing the infected pulp and disinfecting the canals so the tooth can be kept. Our root canal treatment guide explains the steps.
- Remove the tooth when it cannot be restored, which takes away the source completely.
Infections of the gum around a partly erupted wisdom tooth behave a little differently and are usually managed by cleaning under the gum flap. Our article on pericoronitis covers that situation.
When antibiotics are added
Antibiotics are generally reserved for situations where the infection is no longer contained, or where a person is at higher risk. These include:
- swelling that is spreading into the cheek, under the jaw, around the eye or into the neck
- fever, feeling generally unwell, or swollen glands in the neck
- a weakened immune system, for example from chemotherapy or some medicines
- situations where drainage or treatment cannot be done straight away and the infection is spreading
For a localised abscess in someone who is otherwise well, treating the tooth is usually enough, and your dentist may not prescribe anything. That is a clinical judgement based on what is safest and most effective, not a refusal of care. If antibiotics are prescribed, take them exactly as directed.
Go to hospital for these signs
A dental infection that spreads into the deep spaces of the face and neck can become dangerous quickly. Go to an emergency department, rather than waiting for a dental appointment, if you notice:
- difficulty swallowing, breathing or opening your mouth
- swelling under the tongue, under the jaw or down the neck
- swelling that closes the eye
- high fever, or feeling very unwell
Our guide to facial swelling from a spreading dental infection explains these warning signs in more detail.
Easing pain until you are seen
For dental pain, over-the-counter paracetamol or ibuprofen, taken as directed on the packet and if they are safe for you, often work better than people expect. Ask a pharmacist if you have other health conditions or take regular medicines. A cold pack held on the outside of the cheek can ease swelling, and chewing on the other side helps. Avoid putting aspirin or other tablets directly on the gum, which can burn the tissue. Our article on easing a toothache at night has more practical tips, but none of these replace a dental visit.
What people ask us
Can a GP give me antibiotics instead of seeing a dentist?
A GP can treat a spreading infection, but tablets on their own leave the source behind, so you will still need dental treatment to stop it returning.
Should the infection go away before the tooth is treated?
Not usually. In most cases the dentist can numb the area and treat the tooth while it is infected, and treatment is often what brings the fastest relief.
How soon will I feel better after treatment?
Pressure pain often eases within a day or two of drainage or root canal treatment, although the tooth may feel tender for a little longer. Call us if swelling increases or you feel unwell.
If you have an aching or swollen tooth, the team at Lumi Dental can find the source and treat it. See our current offers or book with a general dentist in Melrose Park.
This article is general information and not a substitute for personal dental or medical advice.
