The purpose of this study was to evaluate the shear bond strength of E-max pressed laminate
veneers discs cemented to the surface treated of zirconia core discs for repairing porcelain veneer
chipping situations. A total of 40 Zirconia discs (n=40) were divided into four groups according
to their surface treatment. Then 40 laminate veneer e-max press discs were constructed and
subsequently cemented on the different treated surfaces. All specimen surfaces were prepared with
a 30 μm fine diamond rotary cutting instrument with water irrigation for 10 s and dried with oilfree
air. Group 1: Control (n=10) where no surface treatment was applied. Group 2: The discs
surfaces were treated using Cimara Zircon Repair system (Voco, Germany) (n=10). Group 3:
The discs surfaces were conditioned with the zirconia primer Monobond plus (Ivoclar Vivadent)
(n=10). Group 4: The disc surfaces were conditioned using CojetTM Repair system (3M ESPE)
(n=10). Then each Laminate veneer was cemented in place using Rely x unicem self-adhesive
universal resin cement following the manufacturer recommendations. The samples were stored
for 24 hours in distilled water then subjected to shear bond strength test using a universal testing
machine to measure the adhesion strength between bonded e-max and zirconia surfaces. The
debonded surfaces were examined using SEMicroscope to reveal the failure nature for each group.
The zirconia surfaces were analyzed using EDX (energy dispersive x-ray) to reveal the dominant
elements left on the surface after debonding. Data were collected, tabulated and statistically
analyzed with ANOVA test, followed by Tukey's post hoc pairwise comparisons (α=0.01). Zirconia
surfaces treated with (Cimara Zircon Repair System) exhibited superior Shear bond strength values.
With the limitation of this study it was found that all surface treatments used affected positively the
bond strength between E-max laminate veneers and Zirconia.