| Groups | Luting procedures |
|---|---|
| Group 1 – SBU | A thin layer of the adhesive was applied, gently air-dried for 5 s and light-cured for 10 s with the light unit LED Radii Cal. |
| Group 2 - Silane + SBU | A layer of the silane RelyX Ceramic Primer was applied and gently air-dried for 5 s. The adhesive SBU was applied as described for group 1. |
| Group 3 - Signum Zirconia Bond (SZ) | A layer of the Signum Zirconia Bond part I was applied and gently air-dried for 5 s. Then, a layer of Signum Zirconia Bond part II was applied and light-cured for 40 s with the light unit LED Radii Cal. |
| Group 4 - Z-Prime Plus (ZP) | A layer of Z-Prime Plus was applied, gently air-dried for 5 s, and light-cured for 40 s with the light unit LED Radii Cal. |
| Group 5 - MZ Primer (MZ) | A layer of MZ Primer was applied, gently air-dried for 5 s, and light-cured for 40 s with the light unit LED Radii Cal. |