PRF-Modified Graft Materials in Lateral Sinus Augmentation: A Systematic Review of Histologic Outcome

Background: Platelet-rich fibrin (PRF) has been increasingly investigated as a biological adjunct in maxillary sinus augmentation procedures because of its potential to enhance bone regeneration and graft remodelling. However, the histologic benefits of combining PRF with allograft or xenograft materials during lateral sinus augmentation remain unclear. This systematic review aimed to evaluate the histomorphometric outcomes of PRF-modified graft materials compared with graft materials alone in lateral maxillary sinus augmentation. Methods: This systematic review was conducted according to PRISMA 2020 guidelines and registered in PROSPERO (CRD420261301066). Electronic searches were performed in PubMed, Cochrane Library, and Google Scholar databases for studies published within the last 10 years. Randomized controlled trials and split-mouth randomized studies evaluating histologic and histomorphometric outcomes following lateral sinus augmentation using allograft or xenograft materials with and without PRF were included. A random-effects meta-analysis was conducted, and effect estimates were expressed as Hedges' g and presented with corresponding 95% confidence intervals (CIs). Results: Four randomized clinical studies involving lateral sinus augmentation procedures were included. Histomorphometric findings generally demonstrated higher percentages of newly formed bone and lower residual graft material in PRF-treated groups compared with graft materials alone. Meta-analyses showed a significant increase in newly formed bone, favouring PRF (effect size 0.61; 95% CI: 0.15 to 1.08; p = 0.01), and a significant reduction in residual graft material (effect size -0.65; 95% CI: -1.15 to -0.14; p = 0.01). No statistically significant differences were observed regarding connective tissue/marrow spaces or radiographic bone height. Heterogeneity among studies was low to moderate. Conclusions: The adjunctive use of PRF during lateral maxillary sinus augmentation appears to enhance early bone regeneration and graft remodelling by increasing newly formed bone and reducing residual graft particles. However, radiographic bone dimensions were generally comparable between PRF-treated and control groups. PRF may therefore be considered a promising biological adjunct rather than a substitute for conventional grafting materials. Further standardized randomized clinical trials with larger sample sizes are required to clarify its long-term clinical effectiveness.