Impact of Mesoporous Zinc Oxide Nanoparticles on Diametral Tensile Strength and Flexural Strength of Resin-Modified Glass Ionomer Cement: An In-Vitro Study

Objectives: This study aimed to investigate the effects of incorporating zinc oxide nanoparticles (ZnONPs) and mesoporous ZnONPs into resin-modified glass ionomer cement (RMGIC) on diametral tensile strength (DTS) and flexural strength (FS). Materials and Methods: A total of 70 RMGIC specimens were fabricated and randomly divided into 7 groups (n=10 per group). Group 1 served as the control group. Groups 2 to 4 contained 3wt.%, 5wt.%, and 7wt.% ZnONPs, respectively, and groups 5 to 7 had 3wt.%, 5wt.%, and 7wt.% mesoporous ZnONPs, respectively. ZnONPs and mesoporous ZnONPs were homogeneously incorporated into the RMGIC powder. Disc-shaped (for DTS) and bar-shaped (for FS) specimens were fabricated according to ISO standards. All specimens were stored in distilled water at 37°C for 24 hours before testing. The DTS was measured using a diametral compression test, and the FS was measured by a three-point bending test using a universal testing machine. Data were analyzed by one-way ANOVA and Tukey’s post-hoc test (alpha=0.05). Results: Statistically significant differences were observed in the DTS and FS among the groups (P< 0.001). The 5wt.% mesoporous ZnONPs group exhibited the highest DTS and FS values. The group with 7wt.% ZnONPs showed the lowest DTS and FS values (P<0.05). Conclusion: Incorporation of 5wt.% mesoporous ZnONPs into RMGIC significantly improved its DTS and FS, suggesting that this concentration offers optimal reinforcement of mechanical properties.