Polymer Infiltrated HA/BAG Ceramic Network Composites for Implant Restoration

Objectives: To fabricate polymer infiltrated ceramic network (PICN) composites that can be produced in combination with CAD/CAM for implant restoration.
Methods: Hydroxyapatite/bioactive glass (HA/BAG) scaffolds with different bioactive glass content (10, 15, 20 and 25 wt% BAG) were fabricated by press molding. The polymerizable monomer was penetrated into the high-temperature sintered HA/BAG ceramic blocks and cured to prepare PICNs. The microstructure and phase structure were studied by scanning electron microscope (SEM) and X-ray diffraction (XRD). The flexural strength, compressive strength, elastic modulus and Vickers hardness were measured and compared (n = 10).
Results: The pores of ceramic blocks sintered at 1000°C and 1100°C were interconnected and the resin penetrated evenly. The ceramic blocks at 1200°C formed partially closed pores. The resin hardly penetrates the ceramic blocks sintered at 1300°C. The maximum flexural strength of the PICN is 99.87±4.18MPa. The porosity of this ceramic block is 40.76% and the shrinkage is 9.30%. The Vickers hardness of all PICNs is 0.89~1.96GPa, the compressive strength is 139.09~352.21MPa, and the flexural modulus is 22.26~39.77GPa. At present, the elastic modulus of dental implant materials are: Ti (110GPa), ZrO₂ (220 GPa), glass ceramics (96GPa), Ti-Nb-Sn (40GPa), polyetheretherketone (3~4GPa). During mastication, the elastic modulus of bone (1~30 GPa). Compared with the above implant materials, the properties of PICNs prepared in this study are better matched with human bone.
Conclusions: Sintering temperature significantly affected the mechanical properties. The elastic modulus of PICNs was close to that of natural bone. They may be promising implant materials for CAD/CAM applications.