From hopeless to regenerated: successful preservation of a tooth with massive periapical lesion in an adolescent

Background: Periapical lesions in adolescents present a particular therapeutic challenge due to age related anatomical and physiological characteristics, including greater susceptibility to dental trauma, higher caries risk, wide apical foramen and thin dentinal walls. At the same time, high regenerative capacity offers the possibility of successful treatment even in cases with an initially very poor prognosis. Case Presentation: This report presents a 14-year-old patient with a massive periapical lesion and an iatrogenic root canal perforation of tooth 12. Cone-beam computed tomography (CBCT) imaging revealed an extensive osseous defect with complete perforation of the palatal cortical plate and marked destruction of the vestibular bone. Management included sealing the perforation with MTA under an operative microscope and endodontic treatment followed by apicoectomy with bone graft augmentation and placement of a PRF membrane. After the surgery, the tooth was stabilized with a wire-composite splint until physiologic stability was restored. A four-month follow-up CBCT scan showed complete repair of the osseous defect, homogeneous graft integration, re-established cortical continuity, and preservation of a normal periodontal ligament space. Clinically, stable function and satisfactory esthetics were achieved. Conclusion: This case demonstrates that even large periapical lesions complicated by iatrogenic perforation with an initially unfavorable prognosis can be successfully managed through a combination of advanced endodontic therapy and surgical intervention. A multidisciplinary approach, precise diagnostics, and the use of bioactive materials enabled preservation of the natural tooth and complete recovery of periapical structures in an adolescent patient.