How Do Teeth Get Infected? Causes, Symptoms, and When to See a Dentist
by Neighborhood DentalHow Do Teeth Get Infected?
A tooth becomes infected when bacteria enter the inside of the tooth and reach the dental pulp, the soft tissue that contains nerves and blood vessels. Once bacteria reach this area, they can multiply quickly, causing pain, swelling, and sometimes a dental abscess.
Without treatment, the infection usually does not go away on its own and can spread to nearby tissues, making prompt dental care important.
“Our goal isn’t just to treat infected teeth, we want to help patients understand why they happen and how to prevent them in the future. With today’s technology and treatment options, we can often relieve pain quickly while preserving as much of the natural tooth as possible.”
– Dr. Andrew Johnson | Neighborhood Dental West 26 Street
The Most Common Causes of Tooth Infections
1. Untreated Cavities
The most common cause of an infected tooth is tooth decay.
A cavity starts when the outer enamel is damaged. If left untreated, decay continues deeper through the dentin until bacteria reach the pulp.
At that point, the tooth often becomes infected and may require a root canal or extraction.
2. Cracked or Broken Teeth
Even a small crack can create an opening for bacteria.
Cracks may occur from:
- Biting hard foods
- Sports injuries
- Teeth grinding
- Previous dental work wearing down
Sometimes cracks aren’t visible, especially in our back teeth, but still allow bacteria to enter.
3. Large or Leaking Fillings
Older fillings don’t last forever.
As fillings age, tiny gaps can develop around them, allowing bacteria to accumulate underneath the restoration. Decay can form beneath the filling without causing symptoms until the infection reaches the nerve.
4. Gum Disease
Advanced gum disease creates deep pockets around the teeth.
These pockets allow bacteria to collect below the gumline, eventually affecting the tooth’s supporting structures and potentially causing infection.
5. Dental Trauma
A tooth doesn’t have to break to become infected.
A hard impact from:
- Sports
- Falls
- Car accidents
can damage the nerve inside the tooth. The nerve may slowly die over weeks or months, eventually leading to infection.
What Happens During a Tooth Infection?
When bacteria reach the pulp:
- The nerve becomes inflamed.
- Pressure builds inside the tooth.
- Blood supply decreases.
- The nerve tissue begins to die.
- Bacteria continue multiplying.
- Infection may spread beyond the root.
Eventually, an abscess, a pocket of infection, may develop near the root tip.
Symptoms of an Infected Tooth
Common signs include:
- Persistent toothache
- Pain when chewing
- Sensitivity to hot or cold
- Swollen gums
- Swelling in the face or jaw
- Bad taste in the mouth
- Pimple on the gums
- Loose tooth
- Fever in more severe cases
Some infected teeth stop hurting after the nerve dies, but that does not mean the infection has gone away.
Can a Tooth Infection Go Away on Its Own?
❌ No.
The pain may temporarily improve if the nerve dies, but the bacteria remain inside the tooth.
Without treatment, the infection often continues spreading into the surrounding bone and gums.
That’s why delaying care usually results in more extensive treatment.
How Dentists Treat Tooth Infections
Treatment depends on how severe the infection is.
Root Canal Therapy
If enough healthy tooth remains, a root canal removes the infected pulp, disinfects the inside of the tooth, and seals it to prevent future infection. A dental crown is often recommended afterward to strengthen the tooth.
Tooth Extraction
If the tooth is too damaged to save, removing it may be the healthiest option. Your dentist can discuss replacement options, including dental implants or bridges.
Antibiotics
Antibiotics may be prescribed when swelling or infection has spread beyond the tooth, but antibiotics alone rarely eliminate the source of the infection. Dental treatment is usually still necessary.
How to Prevent Tooth Infections
Many tooth infections are preventable with good oral health habits.
You can reduce your risk by:
- Brushing twice daily with fluoride toothpaste
- Flossing every day
- Visiting your dentist for regular cleanings and exams
- Treating cavities early
- Wearing a mouthguard during sports
- Wearing a nightguard if you grind your teeth
- Addressing chipped or cracked teeth promptly
Frequently Asked Questions
How does a tooth get infected?
A tooth becomes infected when bacteria enter through a cavity, crack, broken filling, or injury and reach the pulp inside the tooth.
Why does a tooth get infected?
Most tooth infections occur because untreated decay or damage allows bacteria to invade the tooth’s inner nerve tissue.
Can brushing fix a tooth infection?
No. Brushing helps prevent infections but cannot eliminate bacteria once the inside of the tooth has become infected.
Is a tooth infection an emergency?
A tooth infection can be an emergency. If you have severe pain, swelling, facial swelling, fever, or difficulty swallowing, contact one of our dentists immediately because these symptoms may indicate the infection is spreading.
What happens if an infected tooth isn’t treated?
Without treatment, the infection can spread into the jawbone, gums, and surrounding tissues. Eventually, the tooth may become impossible to save.
Can a root canal save an infected tooth?
In many cases, yes. Root canal therapy removes the infection while preserving the natural tooth, provided the damage is not too extensive. However, the only way to know if you need root canal therapy is to have an exam with one of our dentists to diagnose the severity of the infection and form a customized treatment plan.
Don’t Ignore Tooth Pain
A tooth infection rarely gets better without treatment. Early care often means simpler treatment, less discomfort, and a better chance of saving your natural tooth.
If you’re experiencing tooth pain, swelling, or signs of infection, the team at Neighborhood Dental provides comprehensive exams and emergency dental care at multiple locations throughout eastern South Dakota. Prompt evaluation can help relieve pain, stop the infection, and restore your oral health.
