Three Courses of Antibiotics and the Tooth Still Hurt

Quick answer: Antibiotics do not cure toothache. They can knock back a spreading infection and buy time, but the bacteria live inside a dead nerve chamber with no blood supply, so no drug reaches them. The tooth has to be opened and cleaned, or removed.

The call

Chaim, 47, from Neve Shamir in RBS Gimmel 2, arrived with a familiar history. Six weeks, three prescriptions, three periods of feeling better followed by the pain returning. He wanted a fourth prescription and a referral to someone who could work out what was wrong.

Nothing was mysterious. The tooth had simply never been treated.

What we found

The lower right second molar. No response to cold — the nerve was dead. Marked tenderness to tapping. A well-defined dark area at the root tip on the x-ray, and a small sinus tract on the gum that had been discharging intermittently, which is why the pain kept partially relieving itself.

The reason antibiotics behaved the way they did is worth understanding, because it comes up constantly.

Inside a tooth with a dead nerve there is a network of canals containing necrotic tissue and bacteria. That space has no blood supply — the blood vessels died along with the nerve. Antibiotics travel in the bloodstream. They cannot reach the inside of the tooth at any meaningful concentration, no matter how many courses you take.

What antibiotics do reach is the tissue around the root tip, where the immune system is fighting the bacteria leaking out. Suppress that battle and the symptoms settle for a week or two. Stop the drug and the bacteria, which were never touched, refill the space. Hence the cycle.

There are situations where antibiotics genuinely matter — spreading facial swelling, fever, difficulty swallowing, a patient who is immunocompromised. In those cases they are a bridge, buying time while the actual treatment happens. Not a substitute for it.

Repeated unnecessary courses also carry real cost: resistance, gut disruption, and — as here — six weeks of a lesion quietly enlarging.

What we did

Root canal treatment. First visit: access, remove the necrotic tissue from all canals, irrigate thoroughly, dress with calcium hydroxide and seal. No antibiotic prescribed, because there was no spreading infection and no systemic involvement.

The pain stopped within 24 hours. The sinus tract closed within a fortnight. The canals were filled three weeks later and the tooth crowned after that.

The outcome

Symptom-free since. The lesion at the root tip had substantially healed on the twelve-month x-ray.

Had he been seen in week one, the treatment would have been identical. The six weeks bought nothing except a larger bone lesion and three courses of antibiotics he did not need.

What to do if this happens to you

1. Treat a second course for the same tooth as a warning sign. Ask what the definitive treatment is.
2. Ask directly: does this tooth need a root canal or an extraction? Those are the only two things that resolve it.
3. Take antibiotics as prescribed if there is swelling or fever — that part is real, and finish the course.
4. Do not delay the dental appointment because you feel better on the tablets. That is the drug, not healing.
5. Get seen urgently if the swelling spreads, especially towards the eye or under the jaw, or if swallowing becomes difficult.
6. Ask to see the x-ray. A dark area at the root tip makes the situation obvious.

Been on antibiotics more than once for the same tooth? Ramat Beit Shemesh Urgent Dental Care will tell you what actually needs doing. 055-985-8845 · WhatsApp https://wa.me/972559858845 · Harav Kook 28/1, Beit Shemesh.

Based on real cases treated at the clinic. Names have been changed.