The Effects of Irradiance on Translucency and Surface Gloss of Different Bulk-Fill Composite Resins: An in vitro Study

PURPOSE: The influence of different light-emitting diode (LED) curing light intensities on the translucency and surface gloss of bulk-fill resin-based composite (RBC) restorative materials was evaluated. MATERIALS AND METHODS: Forty specimens of each RBC (Filtek One bulk-fill posterior, Reveal HD bulk, Tetric N-Ceram, and Filtek Z350) were prepared. The RBCs were shaped into molds and cured using an LED curing light unit at high intensity (1,200 mW/cm(2)) for 20 s and low intensity (650 mW/cm(2)) for 40 s. A spectrophotometer was used to determine the translucency, and a gloss meter was used to evaluate surface gloss. Data were analyzed using one- and two-way analysis of variance (ANOVA), independent t-test, and Tukey’s and Scheffe’s post hoc multiple comparison tests. RESULTS: The highest translucency value was observed for Reveal HD (7.688 ± 0.861) with a high curing intensity, while Filtek One showed the lowest value (1.750 ± 0.376) with a low curing intensity. The materials showed no significant difference in surface gloss with a high curing intensity. With low-intensity light curing, Filtek One showed the highest gloss value (55.270 ± 10.106), while Tetric N-Ceram and Reveal HD showed the lowest gloss values (35.560 ± 6.533 and 35.680 ± 6.648, respectively). CONCLUSION: Curing light intensity had no effect on both the gloss and translucency for all the materials tested, although for Tetric N-Ceram, higher intensity corresponded to higher gloss values while for Filtek One, higher intensity corresponded to a higher translucency value.