Effect of decontamination methods on shear bond strength of resin cement to translucent monolithic zirconia
Objective. The aim of this study was to evaluate the effect of decontamination methods on shear bond strength of resin cement to translucent monolithic zirconia. Material and Methods. Eighty 4-mol yttria-stabilized tetragonal zirconia polycrystal specimens were fabricated. All specimens were subjected to saliva contamination and divided into four groups (n=20) according to the decontamination methods: 70% isopropanol (AL); zirclean (ZC); 5.25% sodium ypochlorite (NaOCL); and no cleaning (NC). All specimens were bonded by using self-adhesive resin cement. Half of the specimens in each group (n=10) were subjected to thermocycling. All specimens were subjected to shear bond strength test in a universal testing machine. Failure modes were evaluated by using a scanning electron microscope (SEM). The data obtained were statistically analyzed by using one-way ANOVA followed by the HSD Tukey test (P < 0.05). Results. ANOVA test revealed a significant difference among the different decontamination methods (P < 0.05). No significant differences were found among NaOCL, ZC, and AL groups as revealed by the HSD Tukey test (P > 0.05). The effect of thermocycling was significantly different in all groups (P < 0.05); whereas, no significant difference was found in group ZC (P > 0.05). (SEM) analysis showed mixed failures in all groups except in group NC where only adhesive failure was observed. Conclusion. Saliva contamination during clinical evaluation significantly decreases the shear bond strength between self-adhesive resin cement and translucent monolithic zirconia. The cleaning gel has an impact on improving the bond strength between resin cement and translucent monolithic zirconia. KEYWORDS Monolithic zirconia; Resin cement; Shear bond strength test; Translucent zirconia; Zirclean.