Effect of femtosecond laser and silica coating on the bond strength of zirconia ceramic

Reasonable zirconia surface pretreatment results in excellent bond strength. This study compared the effects of different surface treatments on the shear bond strength of zirconia. A total of 48 zirconia discs were divided into six separate groups (n = 8) including a Control (CL), Alumina particle blasting (AP), Silica coating (SC), Alumina particle blasting and silica coating (AS), Femtosecond laser (FL) and Femtosecond laser and silica coating (FS) group. Resin block was bound with zirconia using resin cement after performing different surface processing. Shear bond strength (SBS) was measured using a universal testing machine with a crosshead speed of 1 mm min(-1)and analysed through one-way analysis of variance (ANOVA)/Tukey tests. SEM revealed many regular microgrooves structured on the surface by laser irradiation. Some nano-columns and nano-holes were found on the side walls of the groove. SBS test results showed that pretreatment of the femtosecond laser and the conjunctive use of a femtosecond laser and silica coating significantly improved SBS (13.769 +/- 1.570 MPa and 13.516 +/- 1.759 MPa) between zirconia and resin. Owing to limitations of this study, regular microgrooves were structured on zirconia surfaces using femtosecond laser treatment. SBS values of zirconia were significantly improved after femtosecond laser processing and the use of femtosecond laser and silica coating. The influence of surface roughness on the adhesion between zirconia and resin cement was seem more effectively observed in this study.