Table 1.

Materials used in this study.

Material/manufacturer	Resin Matrix	Filler loading
Filtek Z250 XT 3M ESPE, St. Paul, MN, USA	Bisphenol A glycol diether dimethacrylate, diurethane dimethacrylate, bisphenol polyethylene A diglycidyl ether dimethacrylate, triethylene glycol dimethacrylate	Surface-modified zirconia/silica (average size 3µm) and Non-agglomerated/non-aggregated surface-modified silica particles (20nm) - Filler loading: 82 wt% or 68 vol%
Filtek Bulk Fill Flow 3M ESPE, St. Paul, MN, USA	Diurethane dimethacrylate, Substituted dimethacrylate, Bisphenol A polyethylene glycol diether dimethacrylate, Bisphenol A diglycidyl ether dimethacrylate, Benzotriazol, triethylene glycol dimethacrylate, ethyl 4-dimethyl aminobenzoate	Combination of zirconia/silica (size range of 0.01 to 3.5µ) and ytterbium trifluoride filler (size from 0.1 to 5.0µ) - Filler loading: 64.5 wt% or 42,5 vol%,
Grandioso Voco, Cuxhaven, Germany	Bisphenol a diglycidyl ether dimethacrylate, triethylene glycol dimethacrylate, bisphenol A polyethylene glycol diether dimethacrylate	Glass ceramic filler (average size 1µm) and functionalized silicon dioxide nano-particles (20-40nm) - Filler loading: 89 wt%
X-tra Base Voco, Cuxhaven, Germany	Bisphenol A polyethylene glycol diether dimethacrylate, aliphatic dimetacrylate	Filler loading: 75 wt%
TPH 3 Dentsply/Caulk, Milford, DE, USA	Bisphenol polyethylene A diglycidyl ether dimethacrylate, ethyl 4-dimethylaminobenzoate, other excipients	Barium glass silanized borosilicate aluminum, barium fluorine aluminum borosilicate silanized glass, silica - Filler loading: 79 wt% or 61 vol%,
Surefil SDR Dentsply/Caulk, Milford, DE, USA	Polymerizable dimethacrylate resins, polymerizable trimethacrylate resins, polymerizable urethane dimethacrylate	Barium glass and Strontium glass - Filler loading: 68 wt%, 45 vol%

*Data obtained from Manufacturers Brochures and Material safety data sheet (MSDS).