The effects of magnesia and zirconia addition on bioactivity and compressive strength properties of β-wollastonite synthesized from eggshells

Abstract

This study examines the effects of magnesia (MgO) and zirconia (ZrO2) addition on the bioactivity and compressive strength properties of β-wollastonite. Calcium oxide (CaO) that was obtained from egg shells and silica (SiO2) that was obtained from rice husk ash were mixed using a CaO:SiO2 ratio of 45:55 with deionized water and put into an autoclave at 135°C for 8 h to produce β-wollastonite. The compositions used in this study were 90 to 95 wt. % of β-wollastonite, with 5 to 10 wt. % of MgO and ZrO2. Phase, morphological, elemental, and pH changes for each composition during the 7 day bioactivity test were reviewed and explained using XRD, SEM/EDX, and pH. After 7 days of immersion, all samples, namely, 100 wt. % β-wollastonite, 90 wt. % β-wollastonite-10 wt. % MgO, 90 wt. % β-wollastonite-10 wt. % ZrO2, and 90 wt. % β-wollastonite-5 wt. %-MgO-5 wt. % ZrO2 showed decreasing peaks of the β-wollastonite (β-CaSiO3) and found that hydroxyapatite (HA) phase peak was also detected. The morphology of all the samples had evolved from a spherical form on the first day of the immersion to a glassy thin layer of amorphous calcium phosphate (ACP) on the seventh day of soaking. β-wollastonite samples with 5 wt. % MgO-5 wt. % ZrO2 showed the best compression strength compared to other composites. β-wollastonite samples with 5 wt. % MgO - 5 wt. % ZrO2 were found to be suitable as alternative substances for bone replacement because they are bioactive and have good compression strength.