https://doi.org/10.46889/JDHOR.2025.6215 https://athenaeumpub.com/journal-of-dental-health-and-oral-research/ Case Report Management of an Endo-Periodontal Lesion with Guided Tissue Regeneration in a Maxillary Lateral Incisor: One-Year Follow-Up: A Case Report Karina Esmeralda Aguilar-Salazar 1 , Ahtziry Lisset Torres-Solis 1 , Leslie Karina Gamboa-Guerrero 2 , Javier Antonio Garzón- Trinidad 3 , Ismael Duarte Velóz 4 , Yarely Guadalupe Ramos-Herrera 4 , Hugo Alejandro Bojórquez-Armenta 5,6* 1 Resident of Periodontics and Implantology Specialty Program, Faculty of Dentistry, Juarez University of Durango State, Durango 34000, México 2 School of Dentistry, Juarez University of the Durango State, Durango 34000, México 3 Postgraduate Program in Endo-Periodontology, Faculty of Studies Iztacala, National Autonomous University of Mexico (UNAM). Tlalnepantla de Baz 54090, Estado de México, México 4 Department of Periodontics and Implantology, Faculty of Dentistry, Juarez University of the State of Durango, México 5 Department of Endodontics, Faculty of Dentistry, Juarez University of Durango State, Durango 34000, México 6 Department of Endodontics, School of Dentistry, Los Mochis University, Sinaloa 81254, México *Correspondence author: Hugo Alejandro Bojórquez-Armenta, Department of Endodontics, Faculty of Dentistry, Juarez University of Durango State, Canoas s/n, Durango, Mexico; E-mail: hugo.bojorquez@ujed.mx Abstract Introduction: Periodontitis is a multifactorial disease primarily associated with biofilm accumulation, leading to progressive loss of periodontal support and the formation of bone defects. Although traditionally considered independent entities, clinical and anatomical evidence has demonstrated a close relationship between periodontal and pulpal pathologies, particularly in endo-periodontal lesions. According to recent classifications, these lesions may have a primary endodontic, periodontal or combined etiology and are characterized by anatomical communication between the pulp and the periodontium through apical foramina, dentinal tubules and lateral canals. Disease progression facilitates the migration of bacteria and toxins between the tissues, exacerbating their destruction. Therefore, differential diagnosis is essential for defining an appropriate treatment, which must be comprehensive and include both root canal disinfection and periodontal regeneration. Guided Tissue Regeneration (GTR), using collagen membranes and bone substitutes, has proven to be an effective technique for promoting healing and restoring functionality in areas affected by bone and soft tissue destruction, enabling the regeneration of damaged periodontal tissues. Case Report: A 51-year-old female patient presented to the Postgraduate Program in Periodontics and Implantology at UJED seeking to preserve tooth 1.2. Clinical and radiographic examination revealed a defective restoration with intraosseous crater-type root exposure and deep probing depth. The diagnosis was generalized periodontitis, stage III, grade B. Additionally, the endodontic diagnosis was previously treated tooth with asymptomatic apical periodontitis and an endo-periodontal lesion type V according to Simon, Glick and Frank. Nonsurgical retreatment and guided tissue regeneration were indicated to improve the prognosis of the tooth. Objective: To evaluate the clinical and radiographic outcomes of guided tissue regeneration in the treatment of endo-periodontal lesions with infraosseous defects through a detailed analysis of the therapeutic response. The aim is to determine whether this technique significantly enhances bone regeneration and periodontal health, contributing to improved prognosis in affected patients. Conclusion: At 6 months postoperatively, satisfactory bone and soft tissue regeneration was observed in the treated tooth, with significant clinical and radiographic improvement. There was evidence of bone level gain, reduction in probing depth and decreased tooth mobility, indicating favorable periodontal recovery. Keywords: Endo-Periodontal Lesion; Guided Tissue Regeneration; Membrane; Intraosseous Defect; Bone Substitute Citation: Aguilar-Salazar KE, et al. Management of an Endo- Periodontal Lesion with Guided Tissue Regeneration in a Maxillary Lateral Incisor: One- Year Follow-Up: A Case Report. J Dental Health Oral Res. 2025;6(2):1-8. https://doi.org/10.46889/JDHOR. 2025.6215 Received Date: 27-05-2025 Accepted Date: 16-06-2025 Published Date: 24-06-2025 Copyright: © 2025 by the authors. Submitted for possible open access publication under the terms and conditions of the Creative Commons Attribution (CCBY) license (https://creativecommons.org/li censes/by/4.0/).