The success rate of root canal treatment is high, however, about 5% to 15% of treatments will fail. If a root canal treatment is successful, it is permanent. There are some complications with endodontic treatment that will not become apparent immediately upon completion of the root canal procedure. Any root canal complication that allows bacteria to continue to enter the area is likely to cause a treatment failure.
One of the most common reasons for root canal failure is a tooth that has extra or hidden canal branches. These canals can be hard to detect and access with dental instruments, causing one branch to be properly treated while another is overlooked. Other causes for root canal treatment failure are perforations, root fractures, cracked teeth, improper seals, and inadequate dental restorations. It is also imperative the root canal treated area is properly cleaned by your dentist to prevent the likelihood of failure caused by the introduction of bacteria.
Indications that you may have a failed root canal procedure are often the same as those that originally signaled the need for treatment. If you are experiencing pain and swelling longer than the expected initial period of healing, you should contact your dentist immediately. Some signs of failed root canal treatment do not appear until months after the procedure. If you have had root canal treatment and are noticing any signs the area is not symptom-free, it is advised to have the tooth re-evaluated as soon as possible.
For many failed root canal treatments, re-treating the tooth solves the problem. If re-treatment is not successful, root canal surgery or extraction may be necessary. Your dentist may opt to refer you to an endodontic specialist for further evaluation and recommendations for treatment.