Surface Gloss, Radiopacity and Shear Bond Strength of Contemporary Universal Composite Resins

The surface gloss, radiopacity and enamel/dentin shear bond strengths (SBS)s of five commercially available contemporary universal composite resins (CR)s were examined. The tested universal CRs were as follows: G-aenial A’CHORD (GA), Charisma Diamond (CD), Neo SpectraTMST(NS), Filtek(F) and Estelite Asteria(EA). Twelve cylindrical specimens per group were fabricated and gloss measurements were performed using a gloss meter after polishing and darkening. Five specimens of each group were radiographed using a CMOS sensor alongside an aluminum stepwedge, human enamel and dentin. The mean gray values were measured with a computer program. A total of 120 bonded human enamel and dentin specimens were subjected to SBS test. To analyze surface gloss, radiopacity and SBS we used Kruskall–Wallis, Wilcoxon signed rank, Welch tests and one-way ANOVA. Games–Howell, Tukey’s HSD tests, and Dunn’s multiple comparisons were used for multiple comparisons (p < 0.05). In terms of gloss units of the materials after polishing and darkening, the highest surface gloss was achieved with GA, followed by NS, F, CD and EA (p < 0.001). All the tested CRs showed significantly higher radiopacity values in comparison with dentin (p < 0.05). CD and NS presented higher radiopacity values, while other CRs were, in decreasing order; F, GA and EA (p < 0.001). The SBS ranking varied for enamel and dentin, and the adhesive failure was detected at a higher rate. Commercially available contemporary universal CRs display different surface gloss, radiopacity and SBS properties.