Comparison of properties of various modifications of liquid platelet-rich fibrin protocols including sticky bone, platelet-rich fibrin block, and albumin platelet-rich fibrin

Background and Objectives: Platelet concentrates, being autologous, are widely used in regenerative periodontal therapy. Composite biomaterials such as platelet-rich fibrin (PRF) block, sticky bone, albumin PRF (Alb-PRF), and Alb-PRF block combine PRF with bone grafts to enhance both biological activity and mechanical strength. This study aimed to compare the volumetric change, compressive strength, elastic modulus, degradation time, and SEM characteristics among various PRF formulations: leukocyte-PRF (L-PRF), advanced PRF (A-PRF), injectable PRF (i-PRF), sticky bone (i-PRF with bone graft), PRF block (A-PRF+ and i-PRF with bone graft), Alb-PRF, and Alb-PRF block. Materials and Methods: Blood samples from healthy volunteers (aged 20–50 years) were used to prepare the different PRF composites. Each formulation was tested in triplicate for compressive strength, elastic modulus, volume, degradation time, and SEM characteristics. Results: Sticky bone showed the highest compressive strength (304.72 ± 3.05 MPa), followed by PRF block (256.69 ± 2.12 MPa), Alb-PRF block (187.5 ± 3.75 MPa), and Alb-PRF (84.9 ± 3.05 MPa). The highest modulus of elasticity was observed in the PRF block (32.66 ± 1.52 MPa), followed by sticky bone (27.41 ± 1.03 MPa), whereas both Alb-PRF and Alb-PRF block had 16.23 ± 1.52 MPa. Volume measurements showed the PRF block (1.6 cm 3 ) had the highest volume, followed by the Alb-PRF block (1.4 cm 3 ), sticky bone and Alb-PRF (1.2 cm 3 ), and L-PRF, A-PRF, and i-PRF (1 cm 3 ). Conclusion: Sticky bone, PRF block, Alb-PRF, and Alb-PRF block significantly enhance the mechanical strength, volume, and degradation profile of graft materials, supporting their clinical utility in periodontal regeneration.