How can a failed root canal cause a sinus infection (X-ray examples)?

What is failed root canal?

Root canal treatment aims to remove the infection and promote healing in the tissues surrounding the tooth. However, in some cases, it may not be successful in accomplishing this goal.

The term "failure" implies that the tooth has not healed or an infection has reappeared. You may then experience persistent pain and even see your symptoms worsen over time.

However, not feeling pain does not always mean you are safe. In other cases, you may not experience anything at all. This is known as a chronic and asymptomatic infection, which develops slowly and silently over time. But it's only a matter of time before it flares up, leading to complications such as intense pain, gum abscess, and even sinus infection.

The link between a failed root canal treatment and a sinus infection:

First, we need to know how our teeth can be connected to the sinuses.

The sinuses are air-filled cavities located in the skull on either side of the cheeks. They often have a close relationship with the upper back teeth, particularly the molars with multiple roots. As a result, the infections of these teeth or procedures carried out (root canal or extraction) without considering these close anatomical relationships can damage the sinuses and lead to sinusitis of dental origin.

Sinusitis is the medical term for sinus inflammation. It causes an overproduction of fluids, resulting in symptoms like a runny nose, nasal congestion, pain, and pressure around the cheeks.

Now, root canal treatment, when performed correctly, is not the culprit. In fact, it is an effective way to eliminate the root cause of the infection, thus preventing sinus complications in the first place. It involves cleaning and filling the root canals to create a healthy environment for healing.

Unfortunately, sometimes things go wrong, and treatment fails. One of the potential complications is a sinus infection.

In these rare cases, your dentist may have accidentally injured the sinus while performing the root canal treatment, or the tooth may become infected again. In such instances, saliva and bacteria can find their way up the sinus and cause infection.

My dentist accidentally injured a sinus: Can this cause an infection?

You need to know that the sinuses are generally resistant, and minor injuries during the procedure are unlikely to cause any harm. Such lesions often result in a small hole above the root tip. We call this sinus communication because the hole connects the sinus to the mouth.

Sinus communication does not mean infection, although it can have the same symptoms as sinusitis. Usually, after the root canal, it is minor, temporary, and heals on its own in a few days without treatment.

However, if the opening is too large and bacteria persist around that area, they can travel to the sinus, causing the treatment to fail with potential infectious complications.

So, if your symptoms are persisting or worsening after the treatment, it's crucial to consult your dentist for further examination. If a sinus infection is diagnosed, treatment may include antibiotics, root canal retreatment, surgery, or tooth extraction as a last resort.

Some situations where a failed root canal treatment resulted in a sinus infection:

Here are some situations where improperly performed root canal treatment has led to sinus complications:

1. Incomplete Treatment:

If the root canal treatment fails to remove all the infection from the tooth, it will continue to develop. As the infection process progresses, it can pierce the sinus linings and create communication between the tooth and the sinus. If left untreated, the bacteria can spread to these areas and cause sinusitis of dental origin.

2. Instrument Fracture:

During a root canal treatment, your dentist uses sharp and thin instruments to access the canals and clean and shape them.

However, one of the complications that can occur is the fracture of a tool inside the canal. This can prevent your dentist from cleaning and filling your tooth correctly. As a result, bacteria will find space to grow, which can subsequently infect the sinuses.

3. Root Canal Filling Overextension:

If the dentist uses the instruments beyond the root tip, there is a risk of breaking through the sinus lining and pushing bacteria into these areas, leading to sinusitis.

Additionally, during the filling process, there is a high risk that the material will extend past the root canal. In this case, it can leak into the sinuses and cause complications later on.

In summary, a minor injury to the sinus lining during a root canal treatment is usually not a serious issue and will heal on its own within a few days.

However, if the treatment has been performed improperly or failed to eliminate the entire infection, the symptoms may persist or even worsen. One of the possible complications when it comes to the upper back teeth is a sinus infection.

If the pain persists or your tooth is symptomatic again, it is important to see your dentist to address the issue as soon as possible.