Abscess under Root Canal: Don't Ignore It!

Abscess under a root canal tooth
When your tooth is infected, a common solution is root canal treatment. It helps save your natural tooth by removing damaged parts. Otherwise, it would have to be removed, which isn't the best option as nothing can replace your natural teeth (not even implants).

But what if the infection comes back or an abscess forms after a root canal? That's what we're exploring in this article.

The Main Goal of Root Canal Treatment

The main goal of a root canal treatment is to save a tooth that's been infected. We want to remove all those bacteria that have invaded your tooth, causing you pain and discomfort.

But it's not just about providing relief. By clearing the infection, your tooth can be saved and can continue to do its job for years to come.

The root canal treatment should also protect the tooth from future problems. By cleaning, filling, and restoring it, we make sure there are no open gaps where bacteria can sneak in.

Ultimately, once the treatment is done, we want your tooth to be symptom-free. It shouldn't give you any discomfort and must function properly like any other healthy teeth.

Why are Root Canal Teeth Not Immune to Infections or Abscesses?

When we think of dental infections, we often associate them with the nerve's response to a deep cavity. However, that's not always the case, as even teeth without nerves can get infected.

A perfect example is root canal-treated teeth. They lack nerves, yet can still be targets for bacteria, leading to abscesses.

The good news is that the risk of this happening is too low. When the root canal is well-executed, there is a good chance that the tooth will stay healthy for decades.

Even if treatment fails, it's typically not the fault of the root canal procedure itself. Other factors, such as cavities, gum disease, or fractures, are more likely culprits leading to the need for tooth removal.

When an abscess forms under a root canal tooth, several causes could be at play. The most common are:

  1. The initial infection isn't completely resolved: If bacteria persist inside the root canals, they can grow and invade surrounding tissues. The result? Ongoing pain and infection that may progress to form an abscess.

  2. The root canal filling is lacking: The root canal filling must tightly seal the tooth, leaving no space for saliva and bacteria. Otherwise, the tooth can become infected and symptomatic again.

  3. The tooth is not properly restored: One of the major factors leading to complications after root canal treatment is not restoring the tooth in time. Placing a crown or filling as early as possible is essential to protect the tooth from the bacteria-rich oral environment and fractures.

  4. The tooth broke off: Cracks or fractures in the tooth serve as entry points for bacteria, leading to deep infections within the tooth. A root canal tooth is at greater risk as it has already lost so much of its supporting structure.

  5. Poor oral hygiene: Neglecting brushing and flossing regularly leads to more plaque buildup—the main culprit behind cavities and gum disease. Root canal-treated teeth are more vulnerable to cavities, and as bacteria progress, they can cause issues such as infection, bad breath, and even tooth loss.

The Different Types of Infections After Root Canal Treatment

Usually, when a root canal tooth develops an infection, it often happens in the area around the root tip, known as the apex. This condition is termed periapical periodontitis.
periapical periodontitis
As pus accumulates around the apex, it can travel to the gum tissue, leading to a visible swelling known as a gum abscess or gum boil.

The onset and duration of infection can vary from person to person. While some may experience an infection immediately after the procedure, others might notice it months or even years later.

This depends on many factors, including the quality of treatment you received, the restoration, the tooth's condition before the procedure, and your body's reaction against bacteria.

Overall, there are three possible scenarios for infection after root canal treatment:

  • New Infection: This arises in a previously healthy apex, often due to a technical error during the procedure. In other words, the root canal treatment created a pathway for bacteria, resulting in a new lesion. When this happens, pain is typically felt immediately after the procedure.

  • Persistent Infection: This occurs when the initial infection has not fully healed after root canal treatment. It tends to persist when there are complexities in the tooth's anatomy or if a canal is accidentally overlooked during treatment.

  • Relapsing Infection: In this case, the tooth initially starts to heal, but then bacteria find an entry point into the tooth and reactivate again, leading to recurring symptoms. This kind of infection is usually chronic, progressing gradually and slowly, manifesting months or even years after treatment.

The First Signs of an Abscess Under a Root Canal Tooth

The first symptom that often prompts patients to seek help is pain. The nature and intensity of the pain can vary based on the cause and severity of the infection. But it's always triggered or aggravated by pressure, for example when you bite or touch your tooth.

However, you should know that moderate pain after treatment is normal and should diminish over the first week as healing progresses.

Some patients report that their tooth feels different when biting on it, even weeks or months later. This can also be normal, as the underlying bone takes longer to heal. Hence, follow-up appointments every 6 months are important to monitor healing closely.

If you suspect infection after root canal treatment, here are the first questions you should ask yourself:

  1. Does the pain come with swollen gums and an unpleasant taste? Does it get worse instead of fading? Is the tooth extremely sensitive to even the slightest touch? These are classic signs of an abscessed tooth.

  2. Is the pain intensified only upon releasing the bite? If so, the tooth may be broken or cracked.

  3. Do you experience pain with temperature changes? The infection may actually come from another tooth, close to the treated one.

The infection can be silent:

Pain isn't always the sole indicator. In cases of chronic infection, you may not feel anything abnormal. Only an X-ray exam can reveal this type of lesion.

Signs of advanced abscess:

When the infection flares up, and a rapid abscess develops beneath the tooth to the gum, pain can go to another level. It is often described as throbbing and intense, preventing sleep and proper eating. Additional signs include an unpleasant taste, bad breath, pus leakage, a feeling that the tooth is too long, swelling, and fever.
Experiencing severe symptoms? Don't delay in visiting your dentist. Dental infections can never resolve on their own and can worsen over time. Seek professional care to address the root cause and prevent further complications.

What Does an Abscess Under a Root Canal Look Like on X-ray?

Dental abscess on X-rays In the X-ray images, you will notice a dark halo around the root tips. This dark halo is a clear indicator of the accumulation of pus and bone loss in this specific area.

The larger the lesion, the more bone is destroyed and the more extensive the infection.

If left untreated, the infection has the potential to spread further. The affected tooth can become looser and unstable, ultimately falling out.

What's the Next Step?

Never put off addressing a dental infection or abscess. Untreated cases can lead to various complications, some of which can be serious.

The infection has the potential to extend to the jawbone and other facial areas, resulting in symptoms like swelling, fever, pus buildup, and swollen lymph nodes. In advanced stages, the infection can eat away a significant portion of the bone, leading to tooth loss and jaw deformities.

Like many other infections, there's a risk of bacteria entering the bloodstream, affecting vital organs such as the heart, brain, or lungs. In rare cases, a life-threatening complication known as sepsis can occur, leading to a sudden drop in blood pressure and organ failure.

So, the best course of action when you find a tooth abscess or infection is to seek treatment as soon as possible.

How is an abscess under a root canal managed?

Your dentist will first evaluate the tooth's condition and take X-rays to determine if a root canal retreatment is necessary. If the tooth can be saved, the old filling will be removed to drain the abscess. A new root canal treatment (retreatment) will be done to clean, reshape, and fix the tooth.

What if root canal retreatment isn't possible?

Sometimes, root canal retreatment is impossible or insufficient to get rid of all the infection. In such cases, a minor surgery called apicoectomy or root-end surgery may be needed. This procedure, conducted by an endodontist, involves cutting the gum and drilling through the bone to expose the root tip for direct visual access to the infection.

Extraction as a Last Resort

When a tooth is severely infected or damaged, removing it may be the last option. After extraction, you can think about options like a dental bridge or implant to replace the missing tooth.