Dental Abscess Antibiotics: What You'll Get Prescribed and What Happens Next

If you're reading this with a swollen face and a throbbing jaw, we'll get straight to it. The bit most people want to know first: if antibiotics are needed, you'll likely be prescribed amoxicillin, 500mg three times a day for five days. It costs £9.90 on prescription in England (free in Scotland, Wales, and Northern Ireland). You'll start feeling noticeably better within 24-48 hours.

Antibiotics on their own don't fix a dental abscess, though, and this is the bit we really wish more people knew. The tooth itself is the source of the infection, and antibiotics can't reach inside it: there's no blood flow in dead pulp tissue for them to travel through. The real fix is dental treatment, and contrary to the old "wait a week on antibiotics, then come back" routine, that treatment can often happen the same day at a well-set-up practice. Antibiotics have a proper role when the infection has already spread beyond the tooth, but they aren't the answer on their own. We'll walk you through the whole picture.

What You'll Be Prescribed

Amoxicillin is the standard for dental abscesses in the UK, and it has been for decades. It works well against the specific bacteria that cause most dental infections, it's well-tolerated, and the side effects are generally mild. You take one 500mg capsule roughly every eight hours, with or after food, for five days. Fifteen capsules total.

If you're allergic to penicillin, the alternative is metronidazole: 400mg, three times daily, for five days. Metronidazole does come with one important rule: absolutely no alcohol while you're taking it. The interaction causes severe nausea and vomiting, and there's no grey area on this one. Even small amounts. Even the splash of wine in a pasta sauce.

In more severe infections, some dentists prescribe both together. The combination covers a wider range of bacteria, which can matter because dental abscesses often involve several bacterial species at once. But for most abscesses, amoxicillin on its own does the job well.

What's Actually Going On in There

So, what's happened is that bacteria have found their way inside the tooth, usually through a cavity, a crack, or an old filling that's started to fail. Once they're inside, they reach the pulp (that's the living tissue in the centre of the tooth, with the nerve and blood supply), and they set up shop. The pulp tissue dies, the infection spreads out through the tip of the root, and your body's immune response walls the whole thing off into a pocket of pus. That pocket is the abscess.

The swelling you can feel? That's the pressure of the pus building up with nowhere to go. And the taste, that metallic, bitter, foul taste that shows up when the swelling's at its worst, that's the abscess finding a way to drain slightly on its own, which is actually your body trying to help.

Now, the antibiotics work in the tissue around the abscess, killing bacteria at the edges and stopping the infection from spreading further. They're brilliant at that. The swelling goes down, the pressure drops, and the pain goes from unbearable to manageable, often remarkably quickly. But they can't get inside the tooth. There's no blood flow in dead pulp tissue, so the antibiotics have no way to reach the source. That's why the dental treatment afterwards is so important.

The Dangerous Bit: When You Feel Better

This is the thing we really wish more people understood, because we see the same pattern over and over.

Day one: you're in agony, you get antibiotics, and you're desperate for relief. Day three: the swelling's down, the pain's mostly gone, life feels close to normal. Day five: the course finishes, and you feel genuinely good. And the temptation is enormous to just... leave it there. You feel fine. The crisis is over. Why go back to the dentist?

Because the source of the infection is still sitting inside that tooth. The dead pulp tissue, the bacteria, the environment that created the abscess in the first place. And without treatment, weeks or months later, it all comes back. Sometimes worse, because the bacteria that survived the first round of antibiotics can be slightly more resistant the next time.

We see patients who've been through three, four, five courses of antibiotics for the same tooth. Each time the abscess flares up, they get another prescription, it settles down, and they put off the dental treatment because the antibiotics "fixed it." But all that's happening is the cycle is repeating, and the tooth is getting weaker each time. One dental appointment during that window of relief after the antibiotics is all it takes to break the cycle for good.

The Treatment That Actually Fixes It

There are two real fixes, and your dentist will recommend whichever makes sense for the state of the tooth.

A root canal cleans out the dead, infected tissue from inside the tooth, disinfects the canals, and fills them with an inert material. The source of infection is completely removed, but the tooth stays. A crown goes on top to protect it afterwards. At UrgentCare Dental, root canal treatment starts at around £300-£700, and a crown is £650.

If the tooth is too far gone, with too much damage or too much bone loss around the root, then an extraction removes the whole thing. Clean and definitive: if the tooth isn't there, it can't get infected again. A simple extraction costs £149 at UrgentCare Dental, or £399 for a complex one. If it's a wisdom tooth, that's £549.

Both of these can often happen the same day you come in. Modern nerve-block technique gets anaesthesia working even in inflamed tissue, so the old "wait a week on antibiotics, then come back for the tooth" routine has largely given way to same-day treatment where the clinical picture allows. When antibiotics are prescribed alongside — usually because the infection has spread beyond the local area — they work as firefighters buying time for the dentist to do the actual repair, rather than as the treatment themselves.

When to Take It Seriously

Most dental abscesses are painful and unpleasant, but they resolve completely with antibiotics and dental treatment. Genuinely dangerous complications are uncommon, but they do happen, and knowing the signs means you'd catch it early.

If the swelling is spreading quickly, particularly toward your eye, down your neck, or under your jaw, that's the infection moving into deeper tissue, and that needs urgent attention, same day. If you're having trouble breathing or swallowing, that's the swelling affecting your airway, and you should head straight to A&E. And if you're running a fever with chills and feeling genuinely unwell alongside the dental swelling, that can indicate the infection is spreading beyond the local area.

These are rare. But if any of them apply, don't wait for a dental appointment. Get seen immediately.

Where Do You Get the Antibiotics?

The fastest route is an emergency dental appointment. The dentist looks at the tooth, does the actual treatment that removes the source of infection, and prescribes antibiotics alongside if they're clinically needed. At UrgentCare Dental, an emergency appointment is £20, and follow-ups after treatment are free.

If you genuinely can't get to a dentist (stuck at work, middle of the night, weekend), your GP or the 111 service can prescribe antibiotics to hold the infection at bay until a dental appointment is possible. That's a holding measure, not a fix: the tooth still needs seeing to.

The dentist route is better because you get the actual fix rather than just symptom management. Antibiotics alone are a pause button; the dental treatment is the off switch.

The Timeline (So You Know What to Expect)

The timeline really depends on what the infection is doing. For a localised abscess where the infection hasn't spread beyond the tooth, you can often be in, treated, and out the same day. The tooth is sorted, any prescribed antibiotics are working alongside, and you walk away with the source gone rather than just numbed for a week.

If the infection has already spread (swelling moving up toward your eye, down your neck, fever, feeling genuinely unwell), the sequence is a little longer: antibiotics get started straight away, a few days for the spread to come under control, and then the dental treatment once it's safe to anaesthetise and operate in the area. That version is usually about two weeks from the first swollen-face day to fully resolved.

Either way, the £20 emergency appointment is the first step, and it's genuinely one of the best investments in your own comfort you'll make. The sooner the tooth itself is seen to, the shorter the whole thing ends up being.