Effect of Nano-Zirconia on the Mechanical and Biological Properties of Calcium Silicate Scaffolds

The calcium silicate (CaSiO3) scaffolds added with 0, 10, 20, 30, and 40 wt% nano‐zirconia (nano‐ZrO2) with controlable porous structure were fabricated via selective laser sintering. The effects of nano‐ZrO2 content on the microstructure, crystalline phase, and mechanical and biological properties were investigated. The results showed that the compressive strength and fracture toughness of the scaffolds were enhanced by the addition of nano‐ZrO2, and the phase transformation of monoclinic phase (m‐ZrO2) into tetragonal phase (t‐ZrO2) occurred, which was favorable for the reinforcing ability of ZrO2 due to the stress‐induced phase transformation toughening mechanism. However, the excessive amount of nano‐ZrO2 would cause undesired agglomeration, poor sinterability, and weak apatite‐forming ability. In vitro results showed that there were bone‐like apatite layer formation and MG‐63 cells attachment on the surfaces of the scaffolds, indicating the scaffolds possessed good biological properties.