Effect of non-thermal atmospheric pressure plasma on the flexural strength of ceramic/cement bilayer specimens

Abstract

Objectives: The purpose of this study was to explore the effect of low-power, non-thermal atmospheric pressure plasma(NT-APP) treatments on the flexural strength (FS) of ceramic restorations.

Materials and Methods: Six groups of ceramic specimens were made by two factorial study design according to resin cement (absence or presence) and surface treatment methods (no treatment, HF or plasma) before cementation. Variolink N (Ivoclar Vivadent) and IPS Empress CAD ceramic (Ivoclar Vivadent) were used. FS was measured by a three-point bending test with the resin cement facing downward. Two-way analysis of variance (ANOVA) was conducted to examine the effect of cement and surface treatment on FS.

Results: There was a statistically significant interaction effect between cement and surface treatment (p < 0.05). Then one-way ANOVA was conducted and there was a statistically significant difference between 6 groups. Post-hoc Tukey test revealed that FS was statistically significantly higher when HF and cement were applied (262.51 ± 32.08 MPa, p < 0.05) compared to any other groups. There were no statistically significant differences between the control group and plasma-and-cement group (p = 0.237).

Conclusions: Within the limitation of this study, low-power NT-APP failed to improve the FS of ceramic specimen itself or ceramic specimen supported with resin cement.