Strategy for apexification of wide-open apex associated with extensive periapical lesion in a weakened root.

: This case report describes successful apexification for a challenging case involving a 30-year-old man, who suffered from dental trauma involving tooth No. 7 (which had occurred several years earlier) and recently experienced acute periapical abscess in this region. Radiographic analysis revealed incomplete root formation, a wide-open apex, thin root canal walls, and an extensive periapical lesion. Chemomechanical debridement was performed gently using K-files and irrigation with a 1% sodium hypochlorite solution. The root canal was filled with a calcium hydroxide paste, which was replaced periodically. At 18 months post-treatment, an apical barrier tissue and significant reduction of periapical radiolucency were observed; at that time, the entire root canal was filled with gray mineral trioxide aggregate (MTA). At a follow-up 16 months later, the tooth had normal function and periapical repair was complete.