Table 1. Materials used in this study.

Material	Manufacturer	Lot number	Composition
Ultra-Etch	Ultradent, South Jordan, UT, USA	ET463137, ET436237	35% phosphoric acid, cobalt aluminate blue spinel, cobalt zinc aluminate blue spinel
All-Bond Universal	Bisco, Schaumburg, IL, USA	1400004366	MDP, bis-GMA, HEMA, ethanol, water
Filtek Z350XT	3M ESPE, St. Paul, MN, USA	N497426	bis-GMA, UDMA, TEGDMA, bis-EMA, PEGDMA, silica filler, zirconia filler, zirconia/silica (aggregated)

MDP, Methacryloyloxydecyl dihydrogen phosphate; bis-GMA, Bisphenol A glycidyl methacrylate; HEMA, Hydroxyethylmethacrylate; UDMA, urethane dimethacrylate; TEGDMA, triethyleneglycol dimethacrylate; bis-EMA, Ethoxylated bisphenol A dimethacrylate; PEGDMA, poly(ethylene glycol) dimethacrylate.