A root canal procedure saves a tooth by removing infected or damaged pulp, the soft tissue inside the tooth that contains nerves and blood vessels. After the pulp is removed, the inner chamber of the tooth is cleaned, disinfected, and sealed to prevent further infection. While generally highly successful, with success rates ranging from 86% to 98%, a small percentage of treated teeth can develop new infections or experience a recurrence of the original infection, sometimes months or even years later.
Recognizing the Signs
Recognizing the signs of a possible infection after a root canal is important for prompt intervention. One of the most common indicators is persistent or worsening pain, especially when chewing or applying pressure to the tooth. While some discomfort is normal for a few days after the procedure, severe pain that lasts longer than a week or intensifies should be evaluated.
Swelling in the gum tissue around the treated tooth, or even in the face or neck, can signal an infection. This may be accompanied by tenderness to the touch. Another concerning sign is the presence of pus or discharge, which might appear as a pimple-like bump on the gums near the affected tooth, sometimes with a foul taste or odor in the mouth.
Sensitivity to hot or cold temperatures, particularly if it reappears or is a new symptom, can also indicate an infection. A tooth that has undergone a root canal can also become discolored, appearing darker, gray, or yellow. In more severe cases, a fever might develop, indicating that the infection has spread beyond the immediate tooth area.
Understanding the Causes
Infections can develop in a tooth after a root canal for several reasons, often related to how thoroughly the original procedure addressed the existing infection or how the tooth was subsequently protected. One common cause is the incomplete cleaning of the intricate root canal system during the initial treatment. This can allow bacteria to resurface if not entirely cleared.
New decay on the treated tooth can expose the root canal filling material to oral bacteria, creating a pathway for pathogens to re-enter the tooth’s internal structure. A cracked or fractured tooth can also allow bacteria to penetrate the tooth and reach the previously treated root canal system.
A compromised or loose crown or filling that no longer effectively seals the tooth can also permit bacteria to infiltrate. If the permanent restoration is delayed after the root canal, the tooth remains exposed, increasing the risk of reinfection. If an existing infection was not fully resolved during the initial procedure, the infection may persist or recur.
Taking Action
If a root canal infection is suspected, taking prompt action is important to prevent the condition from worsening. Ignoring symptoms can allow the infection to spread to surrounding tissues, including the gums and jawbone, and in some cases, even to other parts of the body. Immediate professional evaluation is crucial.
It is advisable to contact a dentist as soon as symptoms arise to schedule an examination. When speaking with the dental office, it is helpful to describe symptoms clearly and emphasize any discomfort or pain experienced. While waiting for the appointment, avoiding self-medication or attempting home remedies is important, as these approaches typically cannot resolve a deep-seated bacterial infection within the tooth.
Over-the-counter pain relievers may offer temporary relief from discomfort, but they do not address the underlying infection. Maintaining good oral hygiene, such as gentle brushing and flossing, can help keep the area clean, but direct pressure on the affected tooth should be avoided.
Professional Diagnosis and Treatment
A dental professional will conduct a thorough examination to diagnose a suspected root canal infection. This process typically begins with a review of the patient’s symptoms and dental history. Clinical examination involves inspecting the tooth and surrounding gums for signs like swelling, tenderness, or the presence of a draining lesion.
X-rays are a standard diagnostic tool, providing two-dimensional images that can reveal changes in the bone around the root tip, which may indicate an infection. For complex cases, three-dimensional imaging techniques such as Cone Beam Computed Tomography (CBCT) are utilized. CBCT scans offer a detailed 3D view of the tooth, root canals, and surrounding bone, helping dentists identify hidden infections, missed canals, or subtle fractures that might not be visible on traditional X-rays.
Treatment options for an infected root canal depend on the diagnosis and the extent of the infection. The most common approach is root canal retreatment, which involves reopening the tooth, removing the old filling material, thoroughly cleaning and disinfecting the canals again, and then resealing them. This procedure aims to eliminate any remaining bacteria or address issues from the initial treatment.
If retreatment is not feasible or successful, or if the infection is localized to the root tip, a surgical procedure called an apicoectomy may be recommended. During an apicoectomy, the gum tissue near the tooth is opened to allow the dentist to remove the infected tissue and the very tip of the tooth’s root, followed by a small filling to seal the end of the root canal. In instances where the tooth is severely damaged or the infection is too extensive to be resolved by other means, extraction of the tooth may become the only remaining option to prevent the spread of infection.