The physicochemical, antibacterial, and mechanical properties of the cement used in fixed dental prostheses show particular importance in the successful treatment. The objective of this in vitro study was to prepare glass ionomer cements (GIC) containing curcumin nanocrystals, as a sealant between the prepared tooth and crown. The prepared cements containing curcumin nanocrystals with concentration of 20% and 30% were evaluated by conventional physicochemical methods, and then, the effects of adding nanocrystals on the cement water solubility and sorption were measured. Finally, the antibacterial effects of the prepared cement were evaluated against three bacterial strains of Streptococcus mutans, Staphylococcus aureus, and Escherichia coli. The results showed that the solubility and sorption of both GIC containing curcumin nanocrystals did not change significantly compared with the control ( p > 0.05 ). The cement containing 20% and 30% curcumin nanocrystals showed significant increase in antibacterial effect ( p < 0.05 ). Considering the suitable physicochemical properties and worthy antibacterial result GIC containing curcumin nanocrystals, it seems that it can be a suitable restorative material.