Inflammatory root resorption is a serious complication of dental trauma, which leads to progressive loss of the root structure. This report describes the treatment a previously traumatized young maxillary lateral incisor, severely affected by inflammatory root resorption. An 11-year-old boy presented with pain and mobility in his maxillary incisors which experienced fall trauma 2 years earlier. Radiographic examination revealed incomplete root development of the right central incisor, associated with advanced inflammatory root resorption and a periapical lesion. Following removal of a prior long-term calcium hydroxide dressing, the root canal was submitted to a 2-week irrigation regimen involving 1.25% sodium hypochlorite and 2% chlorhexidine gluconate. Thereafter, the entire root was filled with mineral trioxide aggregate. The radiographic follow up at 6 months showed arrest of root resorption and initiation of periapical healing in the absence of clinical symptoms and mobility. This was followed by advanced osseous regeneration and re-establishment of the periodontal space at 12 and 24 months. From the present case, it can be concluded that mineral trioxide aggregate obturation can be a viable option that can improve the healing outcomes in cases of severe inflammatory root resorption in young permanent teeth.