Influence of the calcination temperature on morphological and mechanical properties of highly porous hydroxyapatite scaffolds

Bone tissue engineering is a promising approach for bone replacement or augmentation. However, the achievement of a high performing scaffold is still undergoing. In this work, the optimum calcination temperature value of the starting powder for the preparation of highly porous hydroxyapatite scaffold, fabricated by the sponge replica method, was assessed. Hydroxyapatite nanopowder was synthesized by the precipitation method and the influence of four calcinations temperatures (600, 700, 800 and 900 °C) on either powder characteristics or scaffold properties were exhaustively examined. Powder composition and grain size were determined by XRD, TEM and BET analyses. Composition, morphology, porosity, shrinkage and mechanical strength of the sintered scaffolds were determined by XRD, FT-IR, weight and dimension measurements and compression tests. The results showed that increasing the calcination temperature, the grain size of the HA powder increases and a higher grain size leads to a more resistant HA scaffold. The 900 °C calcinations temperature provide the best performing scaffold without inducing any phase transformation. The study here reported highlighted that the calcinations treatment is essential to fabricate high resistant HA scaffolds.