Porous Zirconia Blocks Embedded with Platelet Rich Fibrin for Enhanced Bone Healing: Mechanical and Morphological Assessment

Abstract

AbstractExtensive bone defects can not be repaired with traditional porous blocks composed of graft ceramics concerning the low strength of the materials. In this way, zirconia porous blocks become alternative bone graft material for repairing of extensive bone sites considering their physical properties. The main aim of this study was to evaluate the compressive strength and morphological aspects of porous zirconia blocks embedded with platelet rich fibrin for enhanced bone healing. Porous blocks composed of yttria-stabilized zirconia polycrystals (Y-TZP) were manufactured by the replica method using a polyurethane sponge. Specimens were submitted to a heat treatment at 1 °C/min up to 1500 °C for 120 min. Half of specimens were embedded with an injectable platelet rich fibrin (i-PRF). On i-PRF, harvested blood was immediately centrifuged by using a high-quality table centrifuge at 2700 rpm (408 g) and at room temperature for 3 min. Random specimens were prepared for morphological analyses by optical and scanning electron microscopy. Groups of specimens were mechanically assessed by compressive strength and nano-indentation tests. Porous structures composed of (Y-TZP) revealed high strength values even though interconnected pores had large dimensions. The size of pores was proper for cell migration, bone ingrowth, and angiogenesis. The incorporation of platelet rich fibrin promoted an increase in compressive strength of the porous YTZP structure. However, a decrease in strength of the porous structures was noted with the increase of number and size of pores. Fragile porous zirconia blocks can reveal an adequate strength for surgical handling and tissue healing at extensive bone repair. Also, the incorporation of further bioactive absorbable materials such as platelet rich fibrin increases the strength of the porous structures. The combination of zirconia porous blocks and platelet rich fibrin can enhance the bone healing leading to low risks of clinical issues. Graphical Abstract