Comparative evaluation of third-generation LED-light curing units and their effect on bulk-fill composites—An in vitro study

Abstract Aim: Comparing the effectiveness of third-generation light-emitting diode light-curing devices and their impact on bulk-fill composites is the primary purpose of this study. Materials and Methods: In vitro investigation was carried out on a total of 32 samples of two bulk-fill composites. Four groups ( n = 8) were formed. Half of the specimens of Tetric ® N-Ceram Bulk Fill and Palfique Bulk Flow composites were randomly selected and cured from top with Bluephase ® N LED light curing unit (LCU), and the remaining half with FlashMax P3 WS 4W LED LCU, following instructions provided by the manufacturer. The samples were assessed for degree of conversion (DoC) and microhardness after being submerged in distilled water solution and kept in an incubator for 24 h at 37°C. The two LED LCUs were compared. Standard deviation and mean were used to describe the data. Utilizing the Kruskal–Wallis test, the groups were compared. The independent sample t test was used to evaluate the differences in values between the top and bottom surfaces, and the Bonferroni post hoc test was used for multiple comparisons. The DoC and microhardness were correlated, and this was evaluated using Pearson’s correlation test. Results: The mean values for both parameters were statistically different when the two composites were cured with the LED-LCUs. Both the bulk-fill composites showed better mechanical properties when cured with Bluephase N ® LED-LCU. Conclusions: Bluephase N ® LED-LCU showed better performance than FlashMax P3 WS 4W. The bulk-fill composites showed significant differences in both parameters when cured with the two LED-LCUs.