A 27-year-old male patient complained of dental pain on previously root-treated tooth #17. Intentional replantation (IR) was performed. However, the symptoms returned at 10 months of follow-up, and a sinus tract was detected on the buccal gingiva of tooth #17. The patient refused extraction of the tooth and tooth was scheduled for non-surgical retreatment. Root canal retreatment was initiated with the removal of the previous root filling material while leaving the retrograde filling in situ. After 1 month of intracanal medication, the tooth became asymptomatic with complete healing of the sinus tract and the root canal filling was completed. Clinical and radiographic examination at 1 year follow-up revealed endodontic success with complete resolution of periapical radiolucency. This case report shows that non-surgical retreatment could be a viable alternative for failed IR.