RESUMO
To report a case of endodontic retreatment of a maxillary right canine in which an extra canal was located and successfully treated. A 35-year-old Asian male reported with pain and lingering discomfort in relation to his maxillary right canine after the conventional root canal therapy. Radiographic examination revealed the presence of another undetected and untreated root canal. Therefore, endodontic retreatment was performed and the patient reported complete relief of pain and found to be asymptomatic after a 3-month, 6-month and 1-year recall period. For successful endodontic therapy, the clinician should be aware of the variations in the root canal morphology. The science of extra canal is important in endodontics as failure to locate and treat an extra canal [s] is one of the common causes for failure of root canal treatments