Influence of Primers and Additional Resin Layer on Zirconia Repair Bond Strength.

PURPOSE: To evaluate the influence of alloy/zirconia primer and 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing resin layer treatments on the shear bond strength (SBS) of composite resin to zirconia after aging.

MATERIALS AND METHODS: Sixty zirconia (Y-TZP) blocks were air-abraded (35-μm Al2 O3 ) and divided into 6 experimental groups (n = 10) in terms of primer/resin layer as follows: 1) control, without any primer or resin; 2) AP, Alloy Primer; 3) ZPP, Z-Prime Plus; 4) PL/ZPP, Z-Prime Plus with light polymerization; 5) AP+SEB, Alloy Primer along with light-cured bonding resin of a self-etch adhesive system (SE Bond); and 6) ZPP+SEB, Z-Prime Plus with SE Bond. After composite resin placement and light polymerization, the specimens were stored in distilled water (37°C for 4 months) and thermal-cycled for 6000 cycles. The SBS was tested with a universal testing machine. Statistical analysis of the SBS data was performed with one-way ANOVA, followed by HSD Tukey test (α = 0.05).

RESULTS: There were significant differences between the groups (p < 0.001, F = 116.5). All the groups revealed significantly higher SBS than the control (p < 0.001). ZPP+SEB group exhibited the highest SBS (16.14 ± 2.52 MPa) and AP group the lowest SBS (7.00 ± 1.97 MPa) among experimental groups; both had significant differences with the other groups (p < 0.001). There were no significant differences between ZPP, PL/ZPP and AP+SEB groups (p > 0.05).

CONCLUSIONS: The bond strength between zirconia ceramic and composite resin was affected by different primers/resin layer. Applying an MDP-containing resin layer along with both primers resulted in significant enhancement of SBS. This improvement for Z-Prime Plus was significantly higher than that of Alloy Primer. This article is protected by copyright. All rights reserved.