Rehabilitation of the posterior maxilla with dental implants is frequently complicated by insufficient residual bone height resulting from alveolar ridge resorption and maxillary sinus pneumatization. Lateral sinus floor elevation has become a predictable and widely accepted procedure for increasing bone volume and enabling implant placement in severely atrophic posterior maxillary sites. The long-term success of this procedure is largely dependent on the grafting material used to maintain space beneath the elevated Schneiderian membrane and promote new bone formation.

Deproteinized bovine bone mineral (DBBM), commonly known as xenograft, remains the most extensively documented grafting material for sinus augmentation due to its osteoconductive properties, volumetric stability, and favorable long-term clinical outcomes. However, xenografts are characterized by slow remodeling and prolonged persistence of residual graft particles, which may delay replacement by vital bone. Consequently, strategies to enhance the biological activity of xenografts and accelerate bone regeneration have become an area of considerable research interest.

Leukocyte- and platelet-rich fibrin (L-PRF) is a second-generation autologous platelet concentrate containing a fibrin matrix enriched with platelets, leukocytes, cytokines, and growth factors including platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and transforming growth factor-β (TGF-β). These biological mediators may enhance angiogenesis, accelerate wound healing, stimulate osteoblast proliferation, and improve bone regeneration.

Several studies have demonstrated promising outcomes when L-PRF is used in sinus augmentation procedures. Mazor et al. reported successful bone formation and implant placement following sinus augmentation using PRF as the sole grafting material after six months of healing. Histological analysis demonstrated the formation of newly regenerated vital bone within the augmented sinus compartment.

More recently, Cortellini et al. conducted a randomized controlled trial comparing L-PRF block and DBBM in lateral sinus floor elevation. Although both techniques allowed successful implant placement after six months, differences in volumetric stability and graft remodeling were observed. The authors suggested that L-PRF-containing grafts may represent a biologically active alternative capable of enhancing healing while maintaining sufficient bone volume for implant placement.

Pichotano et al. further demonstrated that combining L-PRF with DBBM accelerated bone maturation and facilitated earlier implant placement when compared with xenograft alone. Histomorphometric findings revealed greater percentages of newly formed bone and reduced healing times in the L-PRF group.

Despite these promising findings, the available evidence remains limited, and there is no clear consensus regarding whether the addition of L-PRF to xenografts results in clinically significant improvements in bone regeneration, volumetric maintenance, and implant site development. Therefore, a randomized controlled clinical trial comparing xenograft alone versus L-PRF block combined with xenograft during lateral sinus floor elevation is warranted.

Inclusion Criteria:

• Adults aged 21 years or older.
• Partially edentulous posterior maxilla requiring implant-supported rehabilitation.
• Residual bone height between 2 and 5 mm measured by CBCT.
• Good oral hygiene and compliance with maintenance visits.
• ASA I or II patients.
• Signed informed consent.

Exclusion Criteria:

• Uncontrolled systemic diseases.
• Smoking more than 10 cigarettes/day.
• Active sinus pathology or chronic sinusitis.
• Previous sinus augmentation surgery.
• Pregnancy or lactation.
• Bisphosphonate therapy.
• Immunocompromised patients.
• History of head and neck radiotherapy