The main objectives of root canal treatment are to provide long-term comfort, function, esthetics and prevention of infection. Results from systematic reviews with meta-analyses, studies of large sample sizes and practice-based research network studies have indicated high and long-term survival rates for teeth initially treated by means of nonsurgical root canal. Initial costs, lifetime costs, cost-effectiveness, cost utility and cost-benefit of root canal treatment all compare well with the alternatives involving replacement using fixed dental prostheses or single-tooth implants that have a lower incidence of long-term postoperative complications. Ten-year complication rates for retained teeth that have undergone root canal treatment are approximately 4%, compared with approximately 18% for retained single-tooth implant restorations.

However, it is inevitable that some initial root canal treatment may not produce apical healing. From the perspective of health care economics, the alternative to retaining the natural tooth should result in lower total lifetime costs or provide greater lifetime function, freedom from disease, comfort or acceptability to a patient. The high survival rates of dental implants have created a paradigm shift in treatment planning that sometimes has resulted in needless extraction of these teeth.

Torabinejad from Loma Linda University, California, and White from the University of Los Angeles, reported on endodontic treatment options following unsuccessful initial root canal treatment, including

  • nonsurgical endodontic retreatment
  • surgical endodontic treatment
  • tooth replantation
  • autotransplantation
  • extraction with or without replacement

Over the past decade, the outcomes of surgical endodontic treatment have improved substantially because of the use of the microscope, angled ultrasonic surgical instruments, and new root end filling materials such as mineral trioxide aggregate and other new calcium silicate materials. Teeth treated by means of a microsurgical technique had survival rates of 94% at 2 to 4 years and 88% at 4 to 6 years.

Intentional replantation is the insertion of a tooth into its own alveolus after the tooth has been extracted for the purpose of performing treatment, such as root end filling or perforation repair. A systematic review and meta-analysis has reported a mean survival rate of 88% for replanted teeth. Autotransplantation, the transfer of an impacted or erupted tooth from I site to another socket or surgically prepared socket in the same person, can be considered, particularly for younger patients, with an appropriate donor tooth whose ongoing craniofacial growth would allow an implant to become deeply
buried and misplaced.

Conclusion
The first treatment option after failure of root canal treatment should not be extraction of the tooth and replacement by using a fixed prosthesis or a single-tooth implant. Nonsurgical retreatment and apical surgery performed using contemporary techniques to address the cause of remaining periapical disease have a high rate of success. Therefore, these options should be considered before extraction of teeth initially treated by means of nonsurgical root
canal treatment.

Torabinejad M, White SN. Endodontic treatment options after unsuccessful initial root canal treatment: alternatives to single-tooth implants. J Am Dent Assoc 2016;147:214-220.