In some rare cases, a root canal treatment may not fully eliminate the infection, leading to a possible recurrence of the infection. This can happen if the root canal is not thoroughly cleaned or if there are additional canals or branches that were not identified and treated during the initial procedure. Other potential factors that may contribute to a root canal treatment failure include a poorly placed or inadequate filling or crown, a crack or fracture in the tooth, or a new infection that develops after the initial treatment.   However, with proper technique and appropriate follow-up care, the success rate of root canal treatment is very high. To minimize the risk of infection recurrence, it is important to complete the full course of treatment, maintain good oral hygiene, and attend regular dental check-ups. If you experience any symptoms such as pain, swelling, or sensitivity after a root canal treatment, it is important to contact your dentist as soon as possible to ensure that any potential issues are identified and addressed promptly.