Millions of teeth with pulp or perirradicularson pathology saved each year with duct treatment. Endodontics presents a high success rate but despite the advances in knowledge and technique, some cases present post -treatment pathology and require being reimged. An adequate diagnosis to elaborate a successful treatment plan is vital in decision making. CBCT is a fundamental tool for establishing this strategy. The knowledge of the causes that condition the failure will help determine what aspects of the portraction will contribute to its success. The improvements in instrumentation, irrigation and shutter are applicable to this field of endodontics. Finally, the latest meta -analysis about reset in redendodontics indicate that we are facing a predictable technique that is a valid alternative and for the maintenance of natural tooth. Similarly, periapical microcirurge has suffered an impressive advance thanks to new technologies and new biozyramic cements.