The Effect of Sintering Aid on Fabrication of Three-Dimensional Carbonated Hydroxyapatite Porous Scaffolds

Three-dimensional (3D) carbonated hydroxyapatite (CHA) porous scaffolds were successfully fabricated via polyurethane (PU) replication technique. Two sets of porous CHA scaffolds were prepared using: 1) as-synthesized CHA slurry (SCHA) and (2) as-synthesized CHA slurry with the addition of sintering aid, magnesium hydroxide (SCHA+Mg (OH)2). The aim of this study was to investigate the influences of the addition of sintering aid in the fabrication of porous CHA scaffolds in terms of phase purity, crystallinity, architecture, and mechanical properties. Result suggested that both of the fabricated porous scaffolds remained as single phase B-type CHA and free of secondary phases. Interestingly, the use of Mg (OH)2 as sintering aid led to better internal architecture resulted in smoother surface and less micro-cracks/pores formation on the struts since the struts was found to be more densified as compared to SCHA scaffolds. In terms of mechanical properties, SCHA+ Mg (OH)2 scaffolds showed higher compressive strength, indicating that the use of Mg (OH)2 had successfully reduced the sintering temperature and improve the densification of porous scaffolds. Thus, SCHA+ Mg (OH)2 scaffolds was found to be a better choice of scaffold with respect to its handling, compaction strength and architecture with improve strut properties.