Table 1 Materials evaluated in this study

Admira fusion

X-tra

Nanohybrid ormocer based composite

Matrix: Resin ormocer

Filler: Silicon oxide nano filler, glass ceramics filler

(1 µm)

Filler content: 84 (w/w)

1604218

VOCO GmbH,

Cuxhaven, Germany

The restoration was applied at layers that are a maximum of 4 mm thick and adapted with a composite modeling instrument (CompoRoller,Kerr) and light-cured for 40 s

OMNICHROMA

Supra nano filled composite

11, 6- Bis-methacryl ethyl oxycarbonyl amino, UDMA, TEGDMA, Mequniol, Di-butyl hydroxyl toluene and UV absorber

Filler content: 79 (w/w) of spherical silica-zirconia filler mean particle size: 0.3 µm

1602201

Tokuyama Dental, Tokyo, Japan

Resin composite was applied incrementally that are a maximum of 2.5 mm thick and adapted with a suitable instruments. each increment was photopolymerized individually for 20 s

Futurabond M+

Single bond universal LC

2-HEMA (10–25%), Bis-GMA) (10–25%),ethanol (10–25%), acidic adhesive monomer(10 MDP)

2.5–5%),UDMA(2.5–5%),catalyst, pyrogenic silicic acids

pH 2.3

1929068

VOCO GmbH,

Cuxhaven, Germany

One drop of the bond was put on a mixing palette, then the adhesive was applied evenly to the surfaces of the cavity and rubbed it in for 20 s with a disposable applicator, after that the adhesive layer was dried off with dry, oil-free air for at least 5 s in order to remove any solvents, then the adhesive layer was cured for 10 s

Palfique Universal Bond

Self-cured dental universal adhesive

Phosphoric acid monomer, Bis phenol A di (2-hydroxy propoxy) dimethacrylate), Bis-GMA, TEGDMA, 2-HEMA, (MTU-6). Silane coupling agent, peroxide, Borate catalyst, Acetone. Isopropanol and purified water

040EZ8

Tokuyama Dental, Tokyo, Japan

One drop of each bond bottle (A and B) was put on a mixing palette and mixed thoroughly with a disposable applicator, the application was completed within one minute since it had volatile solvents, after mixing the color had changed gradually, the application was completed within 3 min, then the adhesive was applied evenly to the surface then air dry for 30 s

Etchant Gel Vococid

35% orthophosphoric acid

7523

VOCO GmbH,

Cuxhaven, Germany

Etching Gel HV

39 wt% phosphoric acid

162E69

Tokuyama Dental, Tokyo, Japan