Effect of surface pretreatments on surface roughness and repair bond strength of aged machinable hybrid ceramic with nanohybrid resin composite

To evaluate the repair bond strength of a nanohybrid resin composite to aged machinable hybrid ceramic after using three surface pretreatments. Specimens of the hybrid ceramic blocks were grouped into four groups based on the ceramic surface pretreatment: no treatment control group, bur grinding group, HF etched group, and grit-blasting group. All the groups were tested for surface roughness by an optical profilometer. Test groups were subdivided into immediate and aged groups based on aging protocol. A nanohybrid resin composite was placed onto prepared resin/ceramic hybrid material surfaces for the micro shear bond strength test. Deboned specimens were inspected using a stereomicroscope and a scanning electron microscope to determine the failure mode. Data was analyzed using ANOVA and the Tukey's HSD test. One-way ANOVA test for surface roughness showed no significant difference among the differently pretreated surfaces. Two-way ANOVA after aging indicated significant differences of surface pretreatments and aging protocol on MSBSof the nanohybrid composite bonded to hybrid ceramic (p < 0.05). Surface pretreatments increased the bond strength of resin composite bonded to hybrid ceramic material. Aging had a detrimental effect on MSBSof nanohybrid resin composite to hybrid ceramic.