The Chemo-Physical and Biological Properties of Portland Cement/Bismuth Oxide/Zinc Oxide Composites Hydrated by a Novel Calcium Lactate Gluconate (CLG) Accelerant

This objective of this study is to investigate the antibacterial properties and biocompatibility of Portland cement/bismuth oxide/ zinc oxide (PC/Bi2O3/ZnO) composites hydrated by a novel calcium lactate gluconate (CLG) accelerant. The 23.1 wt% CLG aqueous solution and deionized water (DDW) were used to set PC/Bi2O3/ZnO, MTA (mineral trioxide aggregate)-like cements, and commercial ProRoot®WMTA. Changes in setting time, pH values, antibacterial properties, and cell viability were assessed by Vicat needle measurement, pH meter, agar diffusion, and MTT assay, respectively. Unlike set by DDW, the PC/Bi2O3/ZnO, MTA-like cements, and ProRoot® WMTA revealed short setting times and low pH values when set by CLG solution. The agar diffusion test showed a significant decrease in inhibition zone diameter against Streptococcus mutans (p < 0.05) in the ProRoot®WMTA and MTA-like groups when set by 23.1 wt% CLG solution but not in the PC/Bi2O3/ZnO group. The MC3T3-E1 cell-based MTT assay revealed that ProRoot®WMTA set using CLG had significantly higher cell viability than the other groups (p < 0.05). The PC/Bi2O3/ZnO cement hydrated with the CLG solution revealed improved antibacterial properties and biocompatibility over ProRoot®WMTA.