Table 1.

Restorative materials used in the studies.

Restorative Materials	Material Type	Manufacturer	Filler	Polymer Matrix	Photoinitiator
Filtek Ultimate A2	Nanofill	3M ESPE St. Paul, MN, USA	Silica particles, Zirconium particles (78.5 wt%, 63.3 vol%)	Bis-GMA, Bis-EMA, UDMA, TEGDMA, PEGDMA	Camphorquinone, tertiary amines
Estelite Σ Quick A02	Nanofill	Tokuyama Dental, Tokyo, Japan	Composite filler, Silica-zirconia filler (71 vol%)	Bis-GMA, UDMA, TEGDMA	Camphorquinone (RAP Technology®)
Tetric EvoCeram Bleach BLXL	Nanohybrid	Ivoclar Vivadent AG, Schaan, Liechtenstein	Barium glass, ytterbium trifluoride, mixed oxide and copolymers (79 wt%, 60 vol%)	Bis-GMA UDMA TEGDMA	Camphorquinone, Lucirin TPO
Tetric Evoceram Powerfill IVB	Nanohybrid	Ivoclar Vivadent AG, Schaan, Liechtenstein	Barium glass, ytterbium, trifluoride, copolymer, mixed oxide (79 wt%, 53–54 vol%)	Bis-GMA, Bis-EMA, UDMA, Bis-PMA, DCP, D3MA.	Camphorquinone, tertiary amines, Ivocerin, TPO

Bis-GMA—bisphenol A-diglycidyl dimethacrylate; Bis-EMA—ethoxylated bisphenol A dimethacrylate; UDMA—urethane dimethacrylate; TEGDMA—triethylene glycol dimethacrylate; PEGDMA—polyethylene glycol dimethacrylate; Bis-PMA; Propoxylated bisphenol A-dimethacrylate; DCP—tricyclodecane-dimethanol dimethacrylate; D3MA—decandiol dimethacrylate.