Root canal retreatment (Re-RCT) is a specialized endodontic procedure aimed at saving a tooth that has failed to heal or has developed a new infection after initial root canal therapy. The primary goal is to re-establish biological health within the root canal system by removing existing filling materials, eliminating persistent intra-canal bacteria, and re-sealing the root canal space.

Step 1: Clinical and radiographic assessment using targeted CBCT imaging. Step 2: Administration of local anesthesia and isolation with a rubber dam. Step 3: Access opening through the existing dental crown or filling. Step 4: Removal of previous filling materials (gutta-percha and sealer) using solvents and rotary instruments. Step 5: Ultrasonic cleaning, negotiation of missed canals, and copious antibacterial irrigation. Step 6: Placement of intra-canal medicament if performed in two visits, or immediate re-obturation with gutta-percha and biocompatible sealer. Step 7: Placement of a temporary sealing restoration prior to final crown placement.

Evidence-based advantages of root canal retreatment include the preservation of natural dentition, restoration of normal masticatory function, prevention of jawbone loss secondary to tooth extraction, elimination of chronic periapical infection, and avoidance of complex surgical or implant interventions (Ng et al., 2011).

Initial post-operative recovery typically resolves within 3 to 7 days, during which localized inflammatory tenderness subsides. Complete radiographic bone healing and tissue regeneration behind the root tip develop progressively over 6 to 24 months, verified through serial follow-up clinical examinations.

Root canal retreatment is indicated for persistent periapical periodontitis, post-treatment root canal failure, recurrent dental caries beneath existing restorations, missed or untreated root canal anatomy, broken endodontic instruments, coronal microleakage, and cracked or compromised initial root seals.

Prior to root canal retreatment, patients undergo clinical examination and periapical imaging or cone-beam computed tomography (CBCT) to evaluate canal anatomy. Patients should disclose full medical history, including anti-resorptive or anticoagulant medications. Taking prescribed anti-inflammatory medication shortly before the appointment may be advised by the clinician to minimize post-operative discomfort.

Mild and common side effects include post-operative pain and localized tissue swelling. Uncommon risks include instrument separation within the canal, canal ledge formation, or root perforation. Rare but serious complications involve persistent periapical infection requiring surgical apicoectomy, root fracture, or eventual tooth loss.

The patient journey for root canal retreatment begins with a comprehensive diagnostic evaluation, including targeted digital radiographs or cone-beam computed tomography (CBCT). Following diagnosis, the procedure is carried out in one or two visits under local anesthesia, where old filling materials are removed, canals are debrided and medicated, and new sealing materials are placed. Short-term recovery involves mild tenderness manageable with non-prescription analgesics, followed by definitive restorative treatment such as a dental crown to ensure long-term stability and follow-up imaging at 6 to 12 months.