Table 1.

List of the composition of the used materials in this study.

Material (Manufacturer) Code	Composition	Lot number	Fillers %	Manufacturer recommendation
Clearfil Tri-S Bond Plus adhesive One-step self-etch (Kuraray Noritake Dental, Japan) TP	Adhesive: MDP, Bis-GMA, HEMA, hydrophilic aliphatic dimethacrylate, hydrophobic aliphatic methacrylate, colloidal silica, sodium fluoride, dl-camphorquinone, accelerators, initiators, ethanol, water, others (pH = 2.3).	00007A	—	Adhesive (i) Apply bond for 10 s (ii) Dry with mild pressure air flow for 5 s (iii) Light cure for 10 s
Estelite Sigma Quick Universal composite (Tokuyama Dental, Japan) EQ	Composite: Bis-GMA, TEGDMA, silica–zirconia fillers, silica–titania fillers, photoinitiators.	J018	82% (wt.) 71% (vol)	Composite (i) Light cure the composite for 10 s, keeping the curing light tip within a distance of 2 mm from the surface
Silorane system adhesive Two-step self-etch (3M ESPE, USA) SA	Primer: phosphorylated methacrylates, Vitrebond copolymer, Bis-GMA, HEMA, water, ethanol, silane-treated silica filler, initiators, stabilizers (pH: 2.7).	N289224	—	Primer (i) Apply primer for 15 s (ii) Gentle air dry (iii) Light cure for 10 s
	Bond: hydrophobic dimethacrylate, phosphorylated methacrylates, TEGDMA, silane-treated silica filler, initiators, stabilizers.	N209848	—	Bond (i) Apply bond (ii) Gentle air dry (iii) Light cure for 10 s
Filtek Silorane Low shrinkage posterior composite (3M ESPE, USA) FS	Composite: silorane resin, CQ, iodonium salt, electron donor, quartz filler, yttrium fluoride, stabilizers, pigments.	N204592	76% (wt.) 55% (vol)	Composite (i) Light cure the composite for 20 s, keeping the curing light tip within a distance of 2 mm from the surface

HEMA: 2-hydroxyethyl methacrylate; Bis-GMA: bisphenol-A-diglycidyl methacrylate; TEGDMA: triethyleneglycoldimethacrylate; MDP: 10-methacryloyloxydecyl dihydrogen phosphate; CQ: camphorquinone; wt: weight; vol: volume.