The Impact of Different Surface Treatments on Topography and Bond Strength of Resin Cement to Lithium Disilicate Glass Ceramic
To evaluate the influence of different surface treatments on topography, surface roughness, surface energy, and microtensile bond strength stability of resin cement to lithium disilicate glass ceramic. Seventy disc-shaped specimens of IPS e.max Press were divided into seven groups according to the surface treatment: NT – non-treated (control); FSil − hydrofluoric acid (HF) + silane; FPSil − HF + phosphoric acid (HP) + silane; FUSil − HF + ultrasonic bath (U) + silane; FPUSil − HF + HP + U + silane; MEP − Monobond Etch and Prime (MEP); and MEPH − MEP + heating. Topography and surface roughness were evaluated using a 3D laser confocal microscope (3DLCM) and scanning electron microscopy (SEM) and surface energy with a goniometer. The microtensile bond strength (μTBS) was evaluated after storage in distilled water at 37°C for 24 hours and after thermocycling (5,000 cycles, 5°–55° C, 30-second dwell time). Data were analyzed using one-way ANOVA (surface roughness and surface energy), two-way ANOVA (μTBS), Tukey′s HSD post-hoc test, and Student t-test (α=0.05). FUSil, FPSil, and FSil presented similar and highest surface roughness, whereas NT, FPUSil, MEP, and MEPH showed similar, and lowest, roughness values (p<0.05). FPUSil, FPSil, FUSil, and FSil presented a similar and highest surface energy. NT, MEP, and MEPH showed similar and lowest surface energy. Only FSil, FPSil, and MEPH maintained bond strength stability after thermocycling, with FPSil leading to less bond strength reduction, suggesting this protocol is more reliable for bonding resin cements to lithium disilicate glass ceramics.SUMMARY
Objective
Methods and Materials
Results
Conclusion
Experimental setup of the μTBS test.
Representative SEM images (10,000×) of ceramic surfaces submitted to each treatment.
Representative 3DLCM images of lithium disilicate ceramic submitted to all surface treatments with the respective mean (mm) and standard deviation of surface roughness (Sa parameter). The three axes are in mm. Different letters refer to statistically significant difference (Tukey’s HSD, p<0.05).
Means of polar and dispersive components of surface energy (mN/m) for all groups. Orange error bars represent the standard deviation for polar and dispersive components. Black error bars represent the standard deviation for the sum of both components. Bars under the same horizontal line are statistically similar (Tukey HSD, p>0.05).
Failure mode distribution and representative 3DLCM images of different patterns of failure for FSil and MEPH groups.
Contributor Notes