RETRATAMENTO DE CANAIS RADICULARES NA ODONTOLOGIA: PROTOCOLO CLÍNICO, CAUSAS DE INSUCESSO E CONDUTAS BASEADAS NA LITERATURA

Root canal retreatment is a conservative alternative in cases of endodontic failure, aiming to remove the previous filling material, reinstrument, disinfect and refill the root canal system. This article aims to discuss, through a narrative literature review, the main indications, causes, imaging resources, instrumentation, irrigation, relationship with gingival and periodontal alterations and the clinical protocol for endodontic retreatment. Scientific articles and case reports on failure, filling removal, manual and mechanized techniques, guided endodontics and clinical and radiographic follow-up were analyzed. The literature shows that retreatment mainly occurs due to microbial persistence, underfilling, condensation failures, untreated canals, lack of coronal sealing, gutta-percha exposure to the oral environment, iatrogenic events and persistent periapical lesions. The findings indicate that no technique completely removes filling residues, requiring the association of manual instruments, rotary systems, active irrigation, intracanal medication when indicated and adequate coronal restoration. It is concluded that endodontic retreatment must be planned based on clinical, radiographic and, when necessary, tomographic diagnosis, since careful execution favors the maintenance of the natural tooth and reduces the need for surgical procedures or extraction.