Evaluation of the Polymerization Properties of Bulk-Fill Composite Resins

The aim was to evaluate the polymerization properties of bulk-fill composite resins in terms of the degree of conversion (%DC), Vickers hardness (HV). SonicFill (SF, Kerr, CA, USA), Tetric Evo Ceram Bulk-Fill (TECBF, Ivoclar Vivadent Schaan, Lichtenstein), and X-trafil (XTF, Voco GmbH, Cuxhaven, Germany) were investigated. The samples prepared from composites (n = 10)  were polymerized via three different curing modes (standard mode: 20 s, high-power mode: 12 s, extra power mode: 6 s) using a polywave LED. %DC was determined by FTIR-ATR-spectroscopy. HV was measured at the top and bottom of the specimens. Data were analyzed by two way ANOVA, and Bonferroni’s post-hoc respectively (α=0.05). Except TECBF (%41.10 ± 3.1) in three different curing modes, all materials showed no significant inferior %DC. In all curing modes, the highest hardness ratio was found in XTF (0.84 ± 0.03 GPa), and the lowest hardness ratio was found in the TECBF (0.78 ± 0.02GPa). In the cases where the extra power mode of the Valo Led was applied, the lowest degree of conversion and hardness were also measured. It has been observed that the examined properties of some tested materials change with the curing time and power of the light and however, the results are dependent on the material.Extra power mode of the Valo Led negatively affected high viscosity bulk-fill composites in terms of their polymerization properties