https://ir.ymlib.yonsei.ac.kr/handle/22282913/168995 2026-04-15T17:24:21Z https://ir.ymlib.yonsei.ac.kr/handle/22282913/211259 Title: Clinical performance of direct composite resin for anterior space closure: A retrospective evaluation Authors: Kim, Yunhee; Kang, Young-Sin; Jeon, Mi-Jeong; Shin, Yooseok; Shin, Su-Jung; Park, Jeong-Won; 강영신 Abstract: Objective: To evaluate the clinical performance, survival, and complication patterns of direct composite resin for anterior space closure, addressing a lack of long-term data on this conservative esthetic treatment. Materials and Methods: The retrospective study was conducted at a university dental hospital (Gangnam Severance) and analyzed 147 restorations in 53 patients. The mean period of follow-up was 7.05 years, ranging from 2 up to 17 years. Results: Kaplan-Meier analysis showed a 96 % cumulative survival rate with failure (n = 6). The most prevalent findings were repairable complications such as marginal discoloration and deterioration of esthetic form, which occurred more frequently over longer follow-up periods, indicating progressive degradation. Conclusions: Direct composite resin restorations for anterior space closure can demonstrate high clinical durability over an extended period. While this minimally invasive approach provides predictable esthetic and functional outcomes, clinicians should be aware of progressive clinical deterioration, particularly regarding marginal discoloration, which underscores the necessity for periodic maintenance. Clinical Significance: This retrospective evaluation indicates that direct composite resin is a viable, minimally invasive option for anterior space closure. Its acceptable survival rate and repairable complication profile suggest it is a practical alternative to more invasive procedures, although the findings highlight the importance of regular clinical monitoring to manage long-term esthetic degradation. 2026-03-01T00:00:00Z https://ir.ymlib.yonsei.ac.kr/handle/22282913/211512 Title: Immunohistological Characterization of Minced Dental Pulp Transplant in an Ectopic Mouse Model Authors: Lee, Chaehwan; Miyamoto, Yuka; Chen, Wei; Kim, Euiseong; Chang, Insoon; Kang, Mo K. Abstract: Introduction: Dental pulp stem cells have been explored as a potential source for dentin-pulp complex regeneration because of their pluripotency and differentiation capacity. However, cell-based approaches require enzymatic digestion and in vitro expansion, which may alter cell properties and hinder clinical translation. This preliminary proof-of-principle study examines a tissue-based alternative using freshly minced pulp (MP) in an ectopic mouse model as a potentially translatable approach for regenerative endodontics. Methods: Human dental pulp tissue was either minced or enzymatically digested, seeded onto collagen type I scaffolds, inserted into root fragments, and implanted subcutaneously into immunocompromised mice. Results: Histology revealed that MP grafting generated well-organized dentin-pulp-like tissue with high cellularity, vascularization, mineralization, and odontoblast-like cells extending processes into dentinal tubules, whereas dental pulp stem cell grafts formed less organized tissue and mineral deposits. MP-derived tissues also exhibited angiogenic potential, forming vessel-like structures containing pericytes and endothelial cells. Conclusions: This preliminary in vivo mouse study suggests the feasibility of MP transplantation and its potential for dentin-pulp complex regeneration, though further studies are needed to assess long-term outcomes and clinical applicability. 2026-03-01T00:00:00Z https://ir.ymlib.yonsei.ac.kr/handle/22282913/211896 Title: Mechanical behavior of tooth-class II restoration complex with various restorative materials using linear and non-linear finite element analysis Authors: Yu, Young-Ho; Jeon, Mi-Jeong; Shin, Su-Jung; Park, Jeong-Won Abstract: This study aimed to investigate the mechanical behavior of the tooth-class II restoration complex restored with composite resin, ceramic, amalgam, and gold using three-dimensional linear and non-linear finite element analyses (FEA). Previous FEA studies generally assumed linear mechanical properties and bonded interfaces between tooth and restorative materials, which differ from clinical reality, particularly for non-bonded restorations such as amalgam and gold. Therefore, in this study, non-linear mechanical properties and non-bonded contact conditions were adopted for different restorative materials. The results showed that the highest enamel and dentin stresses occurred in amalgam restorations, while the lowest were found in ceramic restorations. Amalgam and gold produced higher stress in enamel and dentin compared with composite resin and ceramic. The higher stress observed in amalgam and gold was mainly associated with the non-bonded (frictional) contact condition, because the stresses in these restorations remained below their reported yield strengths under the applied loading conditions. This study provides mechanical insights into the behavior of the tooth-class II restoration complex and offers a possible mechanical interpretation of previously reported clinical observations. These findings should be interpreted within the limitations of the finite element model and do not directly represent clinical outcomes. 2026-02-01T00:00:00Z https://ir.ymlib.yonsei.ac.kr/handle/22282913/211058 Title: Optimising Outcomes in Endodontic Microsurgery: Evidence, Uncertainties and Future Directions Authors: Kim, Ukseong; Kim, Euiseong Abstract: Endodontic microsurgery (EMS) is a reliable treatment modality for managing persistent or recurrent periapical pathologies, particularly when conventional nonsurgical retreatment is infeasible or has failed. Various factors influence EMS outcomes, among which the lesion type is a key determinant. Isolated endodontic lesions generally exhibit favourable outcomes, whereas combined endodontic-periodontal lesions and through-and-through defects are clinically challenging and associated with less predictable outcomes. The adjunctive use of regenerative procedures, such as bone grafts, barrier membranes and biologically active agents, aims to enhance periapical healing; however, current evidence remains inconclusive, and further studies with clear lesion-type classification are required to determine their true benefits. Guided surgical approaches, including static, dynamic and robot-assisted systems, have been introduced in EMS to enhance surgical precision and predictability. These technologies appear particularly beneficial in small isolated lesions or when critical anatomical structures must be protected, but further studies are required to validate their clinical effectiveness. This review encourages clinicians to approach EMS with a clear understanding of the effect of lesion type on the prognosis, and to critically assess the usefulness of adjunctive regenerative procedures and advanced technologies based on lesion-specific considerations. Although predictable outcomes are mostly dependent on sound diagnosis, thoughtful case selection, and meticulous surgical techniques, accumulating evidence and technical progress suggest that the indications for EMS may be reasonably expanded in well-selected cases. 2026-01-01T00:00:00Z