Effect of light curing units on Degree of Conversion, microhardness and Mechanical properties of a bulk fill composite ; Influência das fontes polimerizadoras no grau de conversão, microdureza e propriedades mecanicas de resinas compostas Bulk-fill

European Union Programme ; Trabalho de Conclusão de Curso (Graduação) ; Objectives: Evaluated mechanical and physical properties of bulk-fill composites (RBC) polymerized with different light-curing units (LCUs). Materials and Methods: Composite discs (2x4 mm thickness) were produced with Tetric EvoCeram Bulk-Fill (TNB), Filtek Bulk-Fill (FBF) and Opus Bulk-Fill (OBF), divided into 5 groups (n=5) according to LCUs: polywave LED Bluephase, polywave LED VALO, monowave LED Radiical, monowave LED Emitter C and quartz–tungsten– halogen Optilux. Degree of conversion (DC) was determined using Fourier transform infrared spectrometer, microhardness (KHN) was measured with a Knoop indenter and mechanical properties with tensile strength diametral (DTS). Data were analyzed using two-way ANOVA and Tukey’s post hoc test (α=0.05). Results: The DC showed OBF and TNB was signficant difference than FBF, regardless of LCUs. The Bluephase and Optilux present highest values. Radicall and Emitter present lowest values, regardless composite resin. The KHN showed no statistical diference between RBCs for Bluephase and Optilux. For Valo, Radicall and Emitter, the TNB presented lowest values. Regarding the type of composite resin, the OBF showed no statistical diference between LCUs. The Bluphase and Optilux presented highest values for TNB. The Emitter showed lowest value for FBF, while Bluephase showed highest value. For DTS, regardless composite resin, Bluephase, Valo and Optilux showed highest values. The RBCs presented no statistic diference regardless LCUs. Conclusions: The LCUs influenced in DC, KNH and DTS between RBCs