Abstract
Plenty of surface treatments to zirconia (ZrO2) are available. However, the long-term hydrolytic stability is still a major concern for the investigators. This paper explores the effects of different monomer systems on mold enclosed shear bond strength (ME-SBS) of bonding cement to zirconia (ZrO2) using commercially available silane primers with different monomer systems. Eighteen ZrO2 blanks (KaVoT Everest) were subjected to tribo-chemical silica coating and divided into the following primer groups: (1) Sil (control); (2) Composite; (3) G-Multi; and (4) Monobond Plus. Each group was then subdivided into three subgroups (n = 6) depending on storage conditions: (1) 24-h dry storage, (2) 2-month water aging, and (3) 4-month water aging. Elemental analyses and contact angle measurements were conducted. The ME-SBSs and failure modes were analyzed. The data were subjected to the two-way analysis of variance (ANOVA) followed by Tukey's post hoc test for pairwise comparisons (p < 0.05). Similar chemical compositions with marginal differences in content weight (%) were observed. The water contact angle measurements on treated ZrO2 were <32 degrees in all groups. After 4-month water aging, the highest ME-SBS was exhibited by Group 4 (18.3 +/- 6.5 MPa). The Monobond Plus primer systems have the ability to resist hydrolysis at the bonding cement/ZrO2 interface.