Root canal treatment is a common dental procedure designed to save a tooth with infected or inflamed pulp. This treatment removes the infected or inflamed pulp, cleans the chambers, and seals the space to prevent further infection. While highly successful, it is possible for a tooth that has undergone a root canal to become infected again, sometimes months or even years later. This article explores the reasons for reinfection, its signs, diagnosis, treatment, and prevention.
Reasons for Re-infection
A primary reason for reinfection is incomplete bacteria removal during the initial root canal procedure. Tiny, hidden canals or unusually curved root anatomies can make it challenging to thoroughly clean and disinfect, allowing some bacteria to remain. These residual bacteria can multiply over time, leading to a new infection.
Another common cause is issues with the restoration placed after the root canal. If there is a delay in placing a permanent crown or filling, or if the restoration cracks, loosens, or breaks, bacteria from the mouth can re-enter the treated tooth. This compromises the seal of the cleaned root canal system. New tooth decay forming around the treated tooth can also expose the root filling material to bacteria, leading to reinfection.
Recognizing the Signs
When a root canal becomes reinfected, several symptoms may indicate a problem. Persistent pain or discomfort in the tooth is a common sign, which can range from a dull ache to sharp, intense throbbing, sometimes worsening when chewing or biting down. This pain can spread from the root tip to the surrounding gum and jaw.
Swelling in the gums around the affected tooth can also occur. Tenderness when touching the tooth or when biting is another indicator. A pimple-like bump, known as a fistula or abscess, may appear on the gums near the treated tooth. A persistent bad taste or odor in the mouth, and even tooth discoloration, can also point to a reinfection.
Diagnosis and Treatment Options
Diagnosing a reinfected root canal begins with a thorough dental examination. The dentist will visually inspect the tooth and surrounding gums, and ask about any symptoms experienced. X-rays are used to assess the condition of the root and surrounding bone, helping to identify signs of infection or inflammation.
Advanced imaging, such as a 3D Cone Beam CT scan (CBCT), may be used to gain a more detailed view of the tooth’s internal structure and detect infections not visible on conventional X-rays. Other diagnostic tests, like percussion (tapping on the tooth) or palpation (gently pressing on the gums), can help pinpoint the source of discomfort. Once a reinfection is confirmed, several treatment options are available.
Non-surgical retreatment is the most common approach, involving reopening the tooth to remove the old filling material, thoroughly cleaning and disinfecting the root canals, and then resealing them. This procedure aims to eliminate any remaining bacteria and address issues like missed canals or inadequate initial cleaning. If non-surgical retreatment is not feasible or successful, a minor surgical procedure called an apicoectomy might be recommended. This involves removing the tip of the tooth’s root, then sealing the root end to prevent further bacterial leakage. As a last resort, if the tooth cannot be saved through retreatment or apicoectomy, extraction may be necessary.
Preventing Future Issues
Maintaining excellent oral hygiene is a primary defense against root canal reinfection. This includes brushing teeth at least twice daily with fluoride toothpaste and flossing once a day to remove plaque and food debris, especially around the treated tooth. Using an antibacterial mouthwash can also help reduce bacteria in the mouth.
Regular dental check-ups and professional cleanings are also important for monitoring the treated tooth and identifying any new decay early. Promptly addressing any new cavities or damage to the tooth that could compromise the root canal seal is important. Ensuring a permanent crown or filling is placed on the tooth shortly after the initial root canal procedure provides a protective barrier against bacteria. Additionally, avoiding chewing on hard foods with the treated tooth and addressing habits like teeth grinding (bruxism) can help prevent fractures or damage that could lead to reinfection.