Iranian Endodontic Journal

Abstract

Introduction: Calcium-enriched mixture (CEM) cement is a water-based biomaterial with properties similar to calcium silicate-based cements (CSCs). Zinc oxide (ZnO), a bioactive material widely used for its antimicrobial properties and beneficial biological effects on body tissues, was incorporated into CEM cement in this study. The objective was to evaluate the impact of ZnO nanoparticles (ZON) on the physical, chemical, and mechanical properties of CEM cement. Materials and Methods: ZON powder was blended with CEM cement powder at a 10% weight ratio. The mixture was combined with liquid (1 g powder: 0.33 mL liquid) and cast into test-specific molds. Samples of original CEM cement without ZON served as the control group. The samples were evaluated for changes in setting time (n=6), compressive strength (n=6), solubility (n=10), and pH (n=10). Results: The initial setting time was identical in both groups. ZON incorporation reduced the secondary setting time, though not significantly. Compressive strength remained unchanged. After 7 days, solubility increased significantly in ZON-containing samples. While ZON reduced the pH of CEM cement in deionized water after 5 hours, no significant difference was observed at 24 hours. Conclusion: Incorporating ZON into CEM cement caused minor changes, including a reduced secondary setting time, increased solubility, and transient pH changes, without significantly affecting overall performance.