Influence Of Different Led Curing-Units On Depth Of Cure and Micro-Hardness Of Nano-Hybrid Resin Composite

Purpose: To evaluate the effect of two second generation LED Light curing units and a third-generation polywave LED Ligth curing unit at three different irradiation durations on surface microhardness and detpth of cure of nanofilled composite resin material. Materials and Methods: EliparTM S10, EliparTM Deep Cure-S, VALO Cordless, was evaluated at 10s, 20s, 40s curing periods in this study. A nanofilled composite FiltekTM Z550 that contains camphorquinone as photoinitiator is used as test material. For microhardness test ninety 6 mm diameter, 4 mm deep cylindrical composite blocks in teflon molds were prepared. For each light source at each application times 10 specimen were prepared (n=10) and tested. Also ninety, 4 mm diameter, 6 mm deep cylindrical composite specimens in a split aluminum mold polymerized with three different light sources at three different durations (n=10) were tested for depth of cure measurement. Data were analyzed statistically by SPSS (Ver: 22.0) and significance test of the difference between the two means (Kolmogorov-Simirnov), the variance analysis, and the Tukey Test used. Results: The values of cure depth were found significantly higher at 40 seconds of irradiation time for all light sources used (p<0.05). Elipar Deep Cure-S showed the higher top surface microhardness at 40s polymerization (p<0.05) Conclusion: All light devices used in the study provided adequate polymerization of the nanofill composite at all application durations in this study. The highest polymerization depth and microhardness values were achieved at 40 sec. polymerization time for all LCUs.s