Table 1 Materials used in this study

Filtek Z350 XT Universal restorative (Z3P)

3 M ESPE, St. Paul, MN, USA (NA95885)

Bis-GMA, bis-EMA, UDMA, TEGDMA, 20-nm silica, 4–11-nm zirconia filler, Aggregated zirconia/silica cluster filler (cluster particle size of 0.6–10 µm)

63.3 vol./78.5 wt

Body A2

Filtek Z350 XT flowable (Z3F)

3 M ESPE, St. Paul, MN, USA (NA47040)

Bis-GMA, bis-EMA,TEGDMA, 0.1–5-µm ytterbium trifluoride, silica (20 and 75 nm), aggregated zirconia/silica cluster filler (cluster particle size of 0.6–10 µm)

46 vol./65 wt

A2

Surefil SDR flow (SDR)

Dentsply DeTrey GmbH, Konstanz, Germany (2,002,000,121)

Modified UDMA, TEGDMA, EBPDMA, barium-alumino-fluoro-borosilicate, glass, strontium-alumino-fluoro-silicate glass

44 vol./64 wt

Universal

Scotchbond Universal Etchant

3 M ESPE (6,697,834)

32% phosphoric acid

NA

NA

Adper Single Bond 2

3 M ESPE (NC05794)

Bis-GMA, HEMA, dimethacrylates, polyalkenoic acid copolymer, initiators, water, ethanol, and silica nanofillers

NA

NA