Does surface treatment with primers increase the shear bond strength between metallic bracket and monolithic zirconia?

Abstract

Background: This study aimed to investigate the effect of surface treatment with different primers on the shear bond strength (SBS) between metallic brackets and monolithic zirconia crowns. Methods: Sixty-five monolithic zirconia molar crowns were fabricated with CAD-CAM technology. All crowns underwent thermal cycling. After aging, crowns were randomly divided into five groups (n = 13) according to cementation procedures: orthodontic bonding system; primer/composite paste: Transbond XT (TXT) (control); Group M: Monobond Plus (MP) was applied on crowns surfaces then TXT composite paste; Group MT: MP was applied on crown surface then primer/composite paste of TXT; Group Z: Z-Prime Plus (ZP) was applied on crown surface then TXT composite paste; Group ZT: ZP was applied on crown surface then primer/composite paste of TXT was used for bonding the metallic brackets. The bracket-bonded crowns were tested for SBS using a universal testing machine. Results were analyzed using analysis of variance. Results: A statistically significant difference was found between all groups regarding SBS values (p=0.001). Group MT showed the highest SBS value, the control group showed the lowest SBS value (p<0.05). Conclusion: It can be concluded that all bracket-bonded crowns were sufficient to withstand orthodontic forces. Surface treatment with primers contributes to increase the shear bond strength between metallic bracket and monolithic zirconia.