Efficacy of horizontal platelet-rich fibrin on gingival tissue regeneration: Cellular and histological analysis.

Background Horizontal platelet-rich fibrin (H-PRF) is a novel platelet concentrate known for promoting tissue regeneration, the purpose of this study was to assess the impact of H-PRF on gingival defects healing using both in vitro and in vivo approaches. Methods Human gingival fibroblasts (hGFs) were cultured with lipopolysaccharide (LPS), H-PRF, and H-PRF + LPS. Then, cell viability, proliferation, apoptosis and migration were evaluated via fluorescence staining, CCK-8, flow cytometry, scratch and Transwell assays, respectively. Gingival defects were created in a rabbit model and treated with or without H-PRF membranes. Tissue remodeling was evaluated at 14 and 21 days post-surgery using hematoxylin and eosin (H&E) staining, Masson's trichrome staining, and immunohistochemistry (IHC) for E-cadherin, and neovascularization was evaluated by IHC for CD31. Results H-PRF promoted hGFs proliferation and migration and mitigated the negative effects of LPS on hGF viability and apoptosis. In animal model, H-PRF significantly accelerated gingival defect closure, reduced pseudomembrane formation, and promoted the formation of a thicker, stratified squamous epithelium with rete peg formation by day 21. Compared with untreated defects, H-PRF-treated defects exhibited significantly increased collagen deposition and elevated expression of E-cadherin. Moreover, enhanced neovascularization was observed in the H-PRF group, as evidenced by the increased expression of CD31-positive cells. Conclusion H-PRF significantly improved gingival defects healing by enhancing hGF cellular behaviors and promoting epithelialization and neovascularization. These findings support the potential of H-PRF as an effective adjunctive therapy during gingival tissue regeneration.Plain Language Summary Horizontal platelet-rich fibrin (H-PRF) is a platelet concentrate derived from patient's own blood that has gained momentum in regenerative medicine due to its ability to support tissue repair. In our study, we compared the healing process of gingival defects treated with H-PRF to those that healed naturally and found that the defects treated with H-PRF healed more quickly and more completely. The treated areas contained stronger and more organized tissue, with improved blood flow. H-PRF also helps the cells in the gums move to the injury site more effectively, which is important for faster and more complete healing. Our findings suggest that H-PRF could be a useful tool to enhance the outcomes of soft tissue augmentation around natural teeth or implants, which would lead to healthier and stronger gingiva for patients.