Evaluation of Structural Stability, Mechanical Properties, and Corrosion Resistance of Magnesia Partially Stabilized...

Nano Zirconia (ZrO₂) has been used in dental implants due to having excellent mechanical properties and biocompatibility that match the requirements for the purpose. Zirconia undergoes phase transformation during heating: monoclinic (room temperature to 1170 °C), tetragonal (1170 °C to 2370 °C), and cubic (>2370 °C). Most useful mechanical properties can be obtained when zirconia is in a multiphase form or in partially stabilized zirconia (PSZ), which is achieved by adding small amounts of a metal oxide dopant, such as MgO (magnesia). This study aimed to synthesize nano Mg-PSZ from a local resource found in West Kalimantan, Indonesia, and examine its structural stability, biochemical stability, and mechanical properties. Nano Mg-PSZ was prepared from a zircon local to Indonesia, from West Kalimantan Province, MgSO₄∙7H₂O, and polyethylene glycol (PEG)-6000 was used as a template. The obtained t-ZrO₂ after calcination at 800 °C was shown to be stable at room temperature. The highest percentage of the t-ZrO₂ phase was obtained at Zr_0.95Mg_0.05O₂ with a variation of 99.5%. The hardness of Mg-PSZ increased from 554 MPa for ZrO₂ without MgO doping to 5266 MPa for ZrO₂ with a doping of 10% MgO. An in vitro biodegradation test showed that the greater the concentration of MgO in doping the ZrO₂, the greater the degradation resistance of Mg-PSZ in simulated body fluid (SBF) solution.