Five esthetic restorative materials and three GIC were evaluated in this study [Table 1 ].
Materials were polymerized into silicon rings (external diameter 9 mm, internal diameter 6 mm, thick 2 mm) to obtain identical specimens.[27 (link)] Cavities of these rings were slightly overfilled with material, covered with Mylar Matrix Strip (Henry Schein, Melville, NY, USA), pressed between two glass plates and polymerized for 40 s on each side using a curing unit (Celalux II, Voco, Cuxhaven, Germany). One light polymerization mode was used for each material standard: 1000 mW/cm2 for 40 s. The light was placed perpendicular to the specimen surface, at distance of 1.5 mm or less.[27 (link)] The upper surface of each specimen was then polished with fine and superfine polishing disks (Sof-Lex Pop On; 3M ESPE, St. Paul, MN, USA) to simulate clinical conditions.
Thirty cylindrical specimens of each material were prepared in this manner. After polymerization and during the experimentation, the specimens were stored in distilled water at 37°C and 100% humidity. Each material was tested 4 weeks after polymerization.
Materials were polymerized into silicon rings (external diameter 9 mm, internal diameter 6 mm, thick 2 mm) to obtain identical specimens.[27 (link)] Cavities of these rings were slightly overfilled with material, covered with Mylar Matrix Strip (Henry Schein, Melville, NY, USA), pressed between two glass plates and polymerized for 40 s on each side using a curing unit (Celalux II, Voco, Cuxhaven, Germany). One light polymerization mode was used for each material standard: 1000 mW/cm2 for 40 s. The light was placed perpendicular to the specimen surface, at distance of 1.5 mm or less.[27 (link)] The upper surface of each specimen was then polished with fine and superfine polishing disks (Sof-Lex Pop On; 3M ESPE, St. Paul, MN, USA) to simulate clinical conditions.
Thirty cylindrical specimens of each material were prepared in this manner. After polymerization and during the experimentation, the specimens were stored in distilled water at 37°C and 100% humidity. Each material was tested 4 weeks after polymerization.
