Effect of ZrO₂ on Mechanical and Biological Properties of Calcium Phosphate-Based Glass-Ceramics for Biomedical Applications

The effect of ZrO2 addition on mechanical and biological properties of bioactive glass-ceramics with chemical compositions of 60CaO-30P(2)O(5)-3TiO(2)-(7-x)Na2O (x=0,1,3) was investigated. It was found that ZrO2 addition up to 3 mol% contributes to monotonical increase of the glass transition temperature. The micro-hardness increases slightly by 1 mol% ZrO2 addition and keeps constant with further addition whereas 1 mol% ZrO2 addition results in similar to 20% increase of three-point bending strength. When the specimens were soaked in simulated body fluid, complete apatite layers were formed on the specimens regardless of the ZrO2 addition. It is therefore concluded that the toughening contribution of 1 mol% ZrO2 addition has no adverse effect on the bioactivity of calcium phosphate glass-ceramics.