This report describes the management of persistent apical periodontitis by combined non-surgical and surgical retreatments. The patient had a history of trauma to his four mandibular incisor teeth and presented pain, intermittent swelling and a draining sinus tract of 9 years duration. All of the teeth had previously been root-canal treated and undergone two surgical retreatment procedures. Non-surgical retreatment was performed and untreated lingual canals were found in three teeth. This was followed by surgery to correct deficiencies in the root-end fillings and to biopsy the lesions. New post-retained crowns were provided, and nine years later there is evidence of continued healing. Schlagwörter: endodontic retreatment, periapical granuloma, periapical surgery, radicular cyst, treatment outcome