Endodontic retreatment: significance and a systematic review of te major protocols

Introduction: In the endodontic treatment scenario, despite the emergence of techniques and instruments that facilitate the treatment, there are still cases that require retreatment of the treated root canals. Non-surgical endodontic retreatment (NSER) can be performed in one or several visits. Endodontic pain has been the main reason for patient consultations after therapy and affects patient comfort. A condition for successful endodontic retreatment is proper cleaning of the root canals, therefore, special attention must be given to the technique used to remove the filling material, with the most commonly used cement, pastes, and gutta-percha cones. Objective: This systematic review aimed to evaluate the main protocols and techniques for endodontic retreatment. Methods: The present study was followed by a systematic literature review model. Clinical studies were included as case reports, retrospective, prospective and randomized trials with qualitative and/or quantitative analysis. The quality of the studies was based on the GRADE instrument. The risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: The results showed that cleaning and the presence of debris at a speed of 1500 rpm provided greater agility with a smaller number of fractured instruments. Furthermore, the dynamic navigation system enabled the minimally invasive removal of the fiber post with a high degree of precision, without unnecessary removal of the root structure. One visit NSER had lower postoperative pain than multiple visits only for 1 and 30 days. Ultrasonic tips should be considered a good option for endodontic retreatment, especially for cases of bioceramics. Finally, there is a predominance of E. faecalis and P. gingivalis in all phases of endodontic retreatment.