Abscessed Tooth: What It Is and What to Do Today

Maybe it started as a toothache that came and went, and now it throbs with your pulse. The tooth feels too tall when you bite, and there's a sore bump on the gum or a bad taste you can't rinse away. Those are the classic signs of an abscessed tooth.

It's serious enough to call a dentist today. If swelling starts to affect your breathing, swallowing or vision, it belongs in an emergency room. Here is what's going on inside the tooth, and why that decides what fixes it.

What is an abscessed tooth?

Inside every tooth is the pulp, the soft core that holds the nerve and blood supply. It runs from the crown down through each root and opens into the jawbone at the root tip.

Bacteria get in through deep decay, a crack, or a leaking filling, and the pulp becomes inflamed and can die. With no blood flowing through it, the body can't defend that space, so bacteria move out through the root tip into the bone. Your immune system tries to wall them off there, and the pus that collects is the abscess.

Some abscesses start in the gum instead, in a deep pocket between the tooth and gum left by gum disease. The pain feels much the same, but the treatment differs, so an exam and an X-ray come first.

Why does an abscessed tooth throb?

While the pulp is still alive, it sits inside hard walls of dentin and enamel that can't stretch. When inflamed tissue swells inside them, it has nowhere to go, so the pressure lands on the nerve. Each heartbeat pushes a little more blood into that sealed space, and that's why the pain pulses.

Once the pulp dies and pus collects at the root tip, the pressure moves into the bone, which can't stretch either. The pus pushes the tooth up slightly in its socket. That's why the tooth feels tall, and why biting or tapping on it hurts. MedlinePlus, from the National Library of Medicine, describes the pain as continuous. It also lists a pimple-like bump on the gum and swollen neck glands among the signs.

Why did the pain stop if the infection is still there?

The pain can fade for two reasons, and neither one means the infection has gone.

First, the nerve can die. A dead nerve stops sending pain signals, but the bacteria living in the canal keep growing. The American Association of Endodontists notes that the infection around the root may or may not hurt.

Second, the pus can find a way out, tunneling through the bone and breaking through the gum as a small bump that drains. Once it drains, the pressure drops, and so does the pain. That bump can come and go while the infection keeps eating into the bone around the root. MedlinePlus says the same: the toothache may stop once the pressure is relieved, but the infection stays active and keeps spreading.

So a tooth that went quiet still needs an exam, because the X-ray shows what the pain no longer tells you.

When should I call a dentist, and when should I go to the ER?

Call us today if you have a throbbing toothache that won't settle, or a tooth that hurts when you bite on it. The same goes for a bump on the gum, swelling in the gum next to one tooth, or a sore tooth that suddenly went quiet.

Go to an emergency room, or call 911, if you have trouble breathing, speaking, swallowing or opening your mouth. Go too if you have a swollen or painful eye, a sudden change in your vision, or a lot of swelling inside your mouth. Those signs come from the NHS guidance on dental abscesses.

These signs mean the infection has spread past the tooth into the face and neck, where swelling can press on the airway.

Can antibiotics alone fix an abscessed tooth?

No, and the reason goes back to how the abscess formed. Antibiotics travel through your blood, and a dead pulp has no blood supply, so the drug can't reach the bacteria living inside the canal. It can calm the infection in the tissue around the tooth for a while. When the course ends, the source is still sitting in the tooth, and the swelling tends to come back.

The American Dental Association's 2019 guideline also recommends dental treatment instead of antibiotics for most tooth infections in adults. The CDC's summary of that guideline shows when antibiotics do make sense for an abscess. They help when treatment can't happen right away, or when the infection causes fever or makes you feel unwell. Even then, they work alongside treatment of the tooth, not in place of it.

How is an abscessed tooth treated?

Treatment takes the source out. If the infection started inside the tooth and the tooth can be saved, that means root canal therapy.

We numb the tooth with local anesthetic, then open it and clean the infected tissue and bacteria out of the canals. Opening it also gives the pus a way out, and that's what takes the pressure off the area. We shape the canals and seal them so bacteria can't move back in. With the source gone, the body can start repairing the bone around the root tip.

A crown usually follows, because a tooth that has lost its pulp and a lot of its structure breaks more easily under a hard bite. An outside lab makes the crown, so it takes a second visit.

If the words root canal make you a little apprehensive, that's normal. The pain you feel now comes from the pressure of the infection, and treatment relieves it. My earlier post covers what root canal therapy involves.

Removing the tooth is the other way to take the source away, and it's the fallback when a tooth is too broken down to save. When the abscess started in a gum pocket, the treatment is cleaning out that pocket instead.

What can I do for an abscessed tooth until I'm seen?

Call the office first. Tell us what you're feeling, and we'll tell you how soon you need to come in.

Take an over-the-counter pain reliever, such as ibuprofen or acetaminophen, at the dose printed on the label.

Rinse with warm salt water, which MedlinePlus notes can ease the pain. Eat soft food on the other side, and skip anything very hot or cold.

Don't hold an aspirin against the gum. MedlinePlus warns that it irritates the tissue and can leave a mouth ulcer.

Don't hold heat against your face. Heat brings more blood to the swelling.

Don't take leftover antibiotics. The CDC warns that the wrong medicine can delay the right treatment and cause side effects.

What if it starts when the office is closed?

We're open Monday through Thursday, 8:00 AM to 4:30 PM, and closed Friday through Sunday. Call as early in the day as you can, and we do our best to see urgent patients the same day. Our emergency visits page and our post on emergency dental care in Munhall cover the other problems we see.

If the pain is the only problem, the steps above can help you get through to Monday. If the swelling is growing or you have a fever, don't wait for us to open. An urgent care or emergency room can check you and start antibiotics. The CDC summary above covers that case, when dental treatment isn't available yet.

Ready to have it looked at?

Call us at (412) 462-3095 and tell us what you're feeling, or reach us through the contact page.