Objective: This study aimed to investigate the microshear bond strength of
adhesive resin cement to Leucite-reinforced CAD/CAM ceramic and compare it
with that of prewarmed nanohybrid resin composite.
Materials and methods: Sixty Empress CAD ceramic plates were prepared. Each
ceramic plate received five Tygon tube micro-cylinders filled with bonding
agents creating 5 resinous micro-cylinders on each ceramic
plate. In the first group (GpA), they were filled with resin cement,
nanohybrid resin composite as a bonding agent was applied in the second group < br /> (GpB), after warming at 50℃, in the third group (GpC), two prewarming cycles
were performed. Light-curing for 20seconds was
applied. Micro-shear bond strength testing (μSBS) was performed using universal
testing machine with a crosshead speed of 1 mm/min until failure occurred. The
μSBS was calculated in MPa by dividing the load (Newton) over the respective
surface area (mm 2 ).Data were tabulated and analyzed and showed normal
distribution when checked using Kolmogorov–Smirnov test. One-way ANOVA
used to compare between the tested groups for μSBS data followed by Tukey HSD
post-hoc test for pairwise comparisons. Significant level was set at 5% (α=0.05).
Results: One- way ANOVA showed a significant difference between tested groups
(p < 0.001). Where heated composite (two prewarming cycle) showed the highest
mSBS compared to other groups (p < 0.05). Nevertheless, heated composite (one
prewarming cycle) showed an improved μSBS compared to resin cement group,
but the increase was insignificant (p=0.081).
Conclusion: pre-heated nanohybrid resin composites seem to be a potential alternative to resin cement to lute ceramic restorations.