Table 2.

Components and surface treatment protocols of the groups

Groups	Core	Veneering ceramic	Surface Treatment	Fusion material
ZF	Zirconia (inCoris ZI, Sirona Dental Systems, GmbH, Bensheim, Germany)	Feldspathic ceramic (Vita Mark II, Vita Zahnfabrik, Bad Sackingen, Germany)	-Sandblasting (50 μm Al₂0₃) to the zirconia cores -Etching veneers with 4% hydroflouric acid (Bisco Porcelain Etch, Bisco Dental Products, Schaumburg, IL, USA) - silanization of veneers (Monobond Plus, Ivoclar Vivadent, Schaan, Liechtenstein)	Dual-cured resin based cement (Panavia F 2.0, Kuraray Medical Inc., Japan)
ZL	Zirconia (inCoris ZI, Sirona Dental Systems, GmbH, Bensheim, Germany)	Lithium disilicate ceramic (IPS e-max CAD, Ivoclar Vivadent, Schaan, Liechtenstein)		Fusion glass ceramic (IPS e.max CAD Crystall./Connect, Ivoclar Vivadent, Schaan, Liechtenstein)

Groups

Core

Veneering ceramic

Surface Treatment

Fusion material

Zirconia (inCoris ZI, Sirona Dental Systems, GmbH, Bensheim, Germany)

Feldspathic ceramic

(Vita Mark II, Vita Zahnfabrik, Bad Sackingen, Germany)

-Sandblasting (50 μm Al₂0₃) to the zirconia cores

-Etching veneers with 4% hydroflouric acid (Bisco Porcelain Etch, Bisco Dental Products, Schaumburg, IL, USA)

- silanization of veneers (Monobond Plus, Ivoclar Vivadent, Schaan, Liechtenstein)

Dual-cured resin based cement (Panavia F 2.0, Kuraray Medical Inc., Japan)

Zirconia (inCoris ZI, Sirona Dental Systems, GmbH, Bensheim, Germany)

Lithium disilicate ceramic (IPS e-max CAD, Ivoclar Vivadent, Schaan, Liechtenstein)

Fusion glass ceramic (IPS e.max CAD Crystall./Connect, Ivoclar Vivadent, Schaan, Liechtenstein)