On the production of novel zirconia-reinforced bioactive glass porous structures for bone repair

The objective of this study was to develop a replica method for producing zirconia-reinforced bioactive glass (ZRBG) porous structures for bone repair. Four different types of porous structures were produced: zirconia (G1), 58S BG-coated zirconia (G2), zirconia-reinforced BG (G3) and 58S BG-coated zirconia-reinforced BG (G4). A complete characterization of the specimens was performed via SEM-EDS, Archimedes method, 3D X-ray micro-tomography, micro-indentation, compressive strength tests and SBF immersion tests. G3 and G4 specimens presented a BG matrix (~ 33% glassy phase) with dispersed zirconia particles. The porosity of the specimens ranged from 86% up to 93%. BG58S-zirconia groups G3 and G4) exhibited lower YM (38.76 ± 11.20 GPa and 43.49 ± 2.16 GPa) than that of G1 monolithic zirconia specimens (94.39 ± 12.62 GPa), which were more compatible to that of the bone. No significant difference in compressive strength between BG58S-zirconia (G3: 0.41 ± 0.20 MPa; G4: 0.45 ± 0.11 MPa) and zirconia (G1: 0.32 ± 0.11 MPa) was detected observed (p > 0.05). In vitro SBF tests showed a potential bioactivity for ZRBG porous structures.