What Happens If a Tooth Infection Goes Untreated?

Ask the clinic · Bolton Park Dentistry · 9 min read

An untreated tooth infection keeps spreading. It starts inside the tooth or gum, can destroy the bone around the root, and in rare cases moves into the face, neck, or bloodstream, which can be life-threatening. Tooth infections are common, but they’re always serious enough to need a dentist, and an emergency dental clinic in Bolton can usually stop one in a single visit.

Antibiotics alone won’t clear it. They can calm the symptoms for a while, but the bacteria live inside the tooth where medication can’t fully reach. The source has to be removed, most often with root canal therapy, which cleans out the infected nerve and saves the tooth.

When a tooth is too damaged to save, a gentle tooth extraction removes the source of infection. Either way, the goal is the same: get the bacteria out and let the area heal.

If the thought of treatment makes your stomach drop, you’re far from alone. Sedation dentistry can help you stay relaxed. And if you have swelling or throbbing pain right now, request an appointment or call the clinic so you can be seen as soon as possible.

Part 1What is a tooth infection?

A tooth infection (dental abscess) is a pocket of pus caused by bacteria. There are two main types.

• Periapical abscess: Starts inside the tooth, at the tip of the root. Usually caused by deep decay, a crack, or an old injury that let bacteria reach the nerve.
• Periodontal abscess: Starts in the gum and bone beside a tooth. Usually linked to gum disease or trapped debris.

Both types need professional treatment. Neither one heals by itself.

Part 2The stages of an untreated tooth infection

Infections tend to move through a predictable series of stages. How fast they move depends on the bacteria, your immune system, and the tooth involved.

Stage 1: Inflamed nerve (pulpitis)

Decay or a crack lets bacteria reach the nerve. You feel sensitivity to hot and cold that lingers. At this stage, the nerve may still be savable with a filling, or it may need a root canal.

Stage 2: The nerve dies

Inflammation builds pressure inside the tooth, and the nerve dies. Here’s the tricky part. The pain may suddenly stop. Many people think the problem is solved. It isn’t. The dead tissue becomes food for bacteria.

Stage 3: Abscess forms

Bacteria spread out of the root tip into the bone. A pocket of pus forms. You may notice throbbing pain, pain when biting, a pimple-like bump on the gum, or a bad taste when it drains.

Stage 4: Bone loss

The infection slowly dissolves bone around the root. On an X-ray, this shows up as a dark area at the root tip. The tooth may start to feel loose.

Stage 5: Spreading infection

In some people, the infection breaks out of the bone into the soft tissues of the face and neck. This is called cellulitis. Swelling can spread quickly over hours.

Stage 6: Serious complications

Rarely, a dental infection leads to conditions that need hospital care, such as:

• Ludwig’s angina: Swelling under the tongue and jaw that can block the airway
• Sinus infection: Upper back tooth infections can spread into the sinus above
• Sepsis: A body-wide response to infection that can be life-threatening
• Cavernous sinus thrombosis: A very rare clot near the brain, linked to upper tooth infections

These complications are uncommon. They’re also preventable, since they almost always follow an infection that was left alone for a long time.

Some people face higher risk if an infection spreads. That includes people with diabetes, those on chemotherapy or immune-suppressing medications, people who are pregnant, and older adults. If any of these apply to you, treat a toothache as urgent from the very first day.

Part 3Warning signs to watch for

Other signs include:

• Pain when chewing or biting down
• Lingering sensitivity to hot or cold
• A tooth that looks darker than its neighbours
• Tender, swollen lymph nodes under the jaw
• Fever or feeling generally unwell

Part 4Urgent vs emergency: where should you go?

Part 5What to do while you wait for your appointment

If you’ve booked a visit but can’t be seen for a few hours, these steps can make you more comfortable. They won’t treat the infection, but they can help you get through the wait.

1. Rinse with warm salt water every few hours to keep the area clean.
2. Take an over-the-counter pain reliever as directed on the label, if it’s safe for you.
3. Use a cold compress on the outside of your cheek, 15 minutes on and 15 off.
4. Sleep with your head raised on an extra pillow. Lying flat can increase throbbing.
5. Avoid very hot, cold, or sugary foods that can set off the pain.
6. Don’t apply heat to a swollen face. Heat can draw the infection outward.
7. Don’t try to pop a gum bump yourself. Squeezing it can push bacteria deeper.

Keep an eye on your symptoms. If swelling spreads, your fever climbs, or swallowing gets harder, don’t wait for the appointment. Go to an emergency room.

Part 6How tooth infections are treated

Treatment has two parts: remove the source of infection and let the area heal.

Root canal therapy

This is the most common way to save an infected tooth. Here’s how it works:

1. The tooth is frozen so you’re comfortable.
2. The dentist makes a small opening in the top of the tooth.
3. Infected and dead tissue is removed from the canals.
4. The canals are cleaned, shaped, and disinfected.
5. The canals are filled and sealed.
6. A crown is usually placed later to protect the tooth from cracking.

Most people say a root canal feels like getting a filling. The pain you feel before treatment comes from the infection. The treatment is what relieves it.

Extraction

If the tooth is badly broken, cracked down the root, or has lost too much bone support, removing it may be the better choice. The infected area is cleaned, and the site heals over a few weeks. The tooth can later be replaced with an implant, bridge, or partial denture.

Draining the abscess

In some cases, the dentist drains the abscess through a small incision or through the tooth itself to relieve pressure right away.

Antibiotics

Antibiotics are used when the infection is spreading, when there’s fever or swelling, or for people with certain health conditions. They work alongside treatment of the tooth itself.

Part 7Root canal vs extraction: a quick comparison

Your dentist will explain which option gives you the best long-term result for your situation.

Part 8Myths about tooth infections

Part 9How to prevent tooth infections

Most tooth infections start with something small. Preventing them comes down to catching problems early.

• Brush twice a day with fluoride toothpaste
• Floss or use interdental brushes daily
• See your dentist and hygienist on a regular schedule
• Get cavities filled while they’re small
• Wear a sports guard for contact sports to avoid cracked teeth
• Don’t ignore a tooth that keeps aching, even if the pain comes and goes

Part 10Fast, calm care from a top dentist in Bolton

When you have a dental infection, two things matter: getting seen quickly and feeling safe in the chair. Bolton Park Dentistry offers same-day appointments when available for urgent needs, and the team understands how stressful a swollen face or throbbing tooth can be.

The clinic is a trusted family practice with a calm, welcoming environment designed to ease anxiety. Sedation options help patients who feel nervous about treatment. New patients are welcome, and the clinic serves families throughout Bolton and surrounding communities.

As a top dentist in Bolton for full-range care, the team handles hygiene and preventive care, amalgam-free and bonded fillings, crowns, bridges, extractions, root canal therapy, implant restoration, porcelain veneers, teeth whitening, athletic sports guards, TMJ/TMD therapy, and non-surgical gum therapy. Consultations for implants and braces are free, which helps if you’re planning to replace a tooth after an extraction.

Every dentist is licensed with the Royal College of Dental Surgeons of Ontario (RCDSO), so your treatment, consent, and follow-up meet provincial standards.

Visit the office at 14 Parr Blvd Unit 5, Bolton, Ontario L7E 4H1, call 647-496-2336, or email reception@boltonparkdentistry.com. More details are at boltonparkdentistry.com.

Part 11Frequently asked questions

How long can a tooth infection go untreated?

There’s no safe waiting period. Some infections stay contained for months, while others spread within days. Because you can’t predict which way it will go, any suspected tooth infection should be checked by a dentist as soon as possible.

Can a tooth infection spread to the brain?

It’s very rare, but infections from upper teeth can spread toward the brain through veins in the face. This is one reason why swelling near the eye, severe headache, or confusion with a toothache needs emergency care right away.

Will the dentist treat an infected tooth on the first visit?

Often, yes. Many infected teeth can be drained, cleaned, or removed at the first appointment. If swelling is severe, the dentist may start antibiotics first and complete treatment a few days later once the swelling goes down.

Does a root canal hurt?

With modern freezing, most people find a root canal no more uncomfortable than a filling. The tooth may feel tender for a few days afterward, which over-the-counter pain relievers usually manage.

Can I go to the ER for a tooth infection?

Yes, especially if you have facial swelling with fever, trouble swallowing, or trouble breathing. Emergency departments can manage the spreading infection, but you’ll still need a dentist to treat the tooth itself.

Part 12Conclusion

A tooth infection won’t heal on its own, and waiting only gives it more room to spread.
Root canal therapy or extraction removes the source, and most people feel relief within days.
If you notice swelling, throbbing pain, or a bad taste, get seen promptly and keep the problem small.