Purpose: The purpose of this study was to investigate the influence of graphene oxide (GO) and hydrothermal aging on the biaxial flexural strength (BFS) and translucency (TP) of ultrathin monolithic zirconia with different yttria concentrations.
Methods: Disc shaped specimens (n = 120) were milled using zirconia blocks (YZ-HT [HT], YZ-ST [ST], and YZ-XT [XT]) with a diameter of 15.0 mm and a thickness of 0.5 mm. Half of the specimens were immersed in 0.2 wt% GO-water dispersion (HTG, STG, and XTG) and subjected to hydrothermal aging for 10 h. The TP was measured using a reflection spectrophotometer and BFS was tested in a universal testing machine. Data were statistically analyzed with 2-way analysis of variance followed by post-hoc comparisons (α = 0.05).
Results: The lowest mean TP was found in the group of STG aged for 10 h. Hydrothermal aging significantly decreased the TP values in the groups of HTG, STG, and XTG (P < 0.05). Significantly higher TP values were obtained in the groups of XT. Immersion in 0.2 wt% GO-water dispersion significantly improved the BFS values of STG, and XTG for the control and aged groups.
Conclusion: GO leads to decreased translucency while improving BFS for highly translucent zirconia ceramics.
Keywords: aging stability; flexural strength; graphene oxide; monolithic zirconia; translucency.