A root canal-treated tooth is one that has had the infected inner pulp removed, and the root canals cleaned and sealed. While the initial procedure is highly successful in saving a damaged tooth, a root canal can fail over time. When this occurs, a dentist can remove the tooth, which is often the final treatment option. The decision to extract is based on assessing the tooth’s condition and determining if further attempts to save it are likely to succeed. This article explores the circumstances leading to extraction and the replacement options available.
Scope of Practice: Who Can Perform the Extraction?
General Dentists (GPs) perform tooth extractions, including those on teeth that have received root canal treatment. Their training encompasses the necessary surgical techniques to remove a tooth. Most straightforward extractions, where the tooth is visible and easily accessible, are handled in a general dental office setting.
However, a complex extraction might require a referral to an Oral and Maxillofacial Surgeon. These specialists have four to six years of additional hospital-based surgical training. Cases involving severe infection, roots intertwined with the maxillary sinus or a major nerve, or teeth fractured deep beneath the gum line are typically referred for specialized care.
Reasons a Root Canal Tooth Fails
A failed root canal is defined by the persistence or recurrence of infection, pain, or the inability to restore function. The most common pathology leading to extraction is a Vertical Root Fracture (VRF). This crack begins in the root and extends toward the biting surface, creating a pathway for bacteria to enter the jawbone. Once a VRF occurs, the tooth cannot be sealed or saved, requiring extraction.
Another primary cause is secondary infection or coronal leakage. This happens when a new cavity develops or the crown or filling seal breaks down. This breakdown allows bacteria to re-enter the previously cleaned canal system, causing reinfection.
A third reason is severe insufficient bone support due to advanced periodontal disease. The root canal procedure treats internal infection but does not address gum disease that destroys supporting bone. If the tooth loses too much surrounding bone, it becomes mobile and non-functional, necessitating removal. Missed or calcified canals within the complex root canal system can also harbor bacteria, leading to persistent infection.
Trying to Save the Tooth: Alternatives to Extraction
Before recommending extraction, dentists often attempt procedures to preserve the tooth. The most common approach for a failed root canal is non-surgical retreatment. This involves reopening the tooth, removing the old filling material, cleaning and disinfecting the entire root canal system, and then resealing it. Retreatment is often successful when failure is due to a missed canal, incomplete cleaning, or a poor seal.
If retreatment is not an option or has failed, the alternative is an apicoectomy. This minor surgical procedure involves making an incision to access the root tip and surrounding infected bone. The endodontist removes the end of the root and infected tissue, placing a small filling to seal the canal from below. This targeted approach can save a tooth with persistent infection only at the root end.
Restoring the Gap: Replacement Options
Once a tooth is extracted, replacement is recommended to maintain the integrity of the dental arch. Leaving a gap can cause adjacent teeth to shift out of alignment and the opposing tooth to over-erupt into the space.
The gold standard for replacement is the dental implant. This involves surgically placing a titanium post into the jawbone, acting as an artificial root. The post fuses with the bone, providing a stable foundation for a porcelain crown that functions like a natural tooth.
A second option is a fixed bridge. This uses crowns placed on the healthy teeth on either side of the gap to anchor an artificial tooth in the middle. While non-removable, this option requires altering the adjacent teeth.
The third option is a removable partial denture. This uses clasps to attach an artificial tooth to surrounding teeth. While typically the least expensive, it is removable and provides less stability and chewing function than an implant or fixed bridge. Choosing the right option depends on the patient’s overall health, bone density, and financial considerations.