Single-visit regenerative endodontic procedure of necrotic immature lower permanent molar with acute apical abscess

Regenerative endodontic procedures (REPs) of immature teeth with necrotic pulp and apical pathosis focus on passive chemomechanical debridement and usually require multiple visits to enhance the antibacterial effect by placing intracanal medications. However, different case reports showed a favorable clinical and radiographic outcome in single-visit REPs of necrotic immature teeth with symptomatic apical periodontitis or chronic apical abscess. To the best of our knowledge, there are no published reports of single-visit REPs on cases with acute apical abscess. Therefore, this case report aimed to present a successful REP performed in a single visit for immature lower molar with necrotic pulp and acute apical abscess. A 9-year-old female patient referred for the management of the lower right molar (#46), with the chief complaint of localized moderate pain with cold drinks in the lower right molar for 1 week. The extraoral clinical examination revealed no significant findings. Intraorally, tooth #46 revealed a deep occlusal caries, with normal response to palpation, mild pain on percussion, and moderate pain to the cold test. The radiographic examination showed deep occlusal caries approaching the pulp, and periapical radiolucency related to the distal root. It was diagnosed as symptomatic irreversible pulpitis with symptomatic apical periodontitis. After accessing the pulp chamber, the radicular pulp on the mesial root was vital, while necrotic in the distal root. Therefore, vital pulp therapy was done for the mesial root, and REPs initiated for the distal root with intracanal medicament placement. However, the patient failed to show up in the scheduled visit to complete the treatment. The father refused to bring her as she was asymptomatic, and he was afraid of the COVID-19 pandemic situation. One month later, she presented to the clinic with pain and facial swelling in the lower right area of her face. Clinical examination revealed extra- and intraoral swelling related to tooth #46 (i.e., acute apical abscess) with severe pain on palpation and percussion. The patient’s parents insist to finish the treatment or extract the tooth on the same visit. Hence, a single-visit REP was done. After 20 months, clinical and radiographic examinations showed that the tooth became asymptomatic, responded to sensibility tests, and the periapical pathosis healed. It was concluded that regenerative endodontic treatment can be done in single visit in cases with acute apical