Materials and Methods: A blend of BisGMA, BisEMA, UDMA and TEGDMA was prepared with the camphorquinone-amine photo-initiator system. A total of 60wt% of silanized filler particles was added. The filler particles used were: Ba-Al-Si with 0.5µm and/or SiO2 with 0.04µm. From this composition, four types of composites with differences in the relationship between filler particles were prepared. A ratio in % of Ba-Al-Si and SiO2, respectively, were: G1-100/0, G2-90/10, G3-80/20 and G4-70/30. During the preparation of the samples, three polymerization methods were used: CL–ContinuousLight, SS–SoftStart and PD–PulseDelay. FreeLight2LED unit was used for photo-activation. Samples (n=10) with 7.0x2.0x1.0mm (length x width x height) were made and the DC was analyzed using Fourier transform infrared spectroscopy (FTIR).The same samples (n=10) were subjected to FS and FM using an universal testing machine (Instron) with a crosshead speed of 0.5mm/min. ANOVA and Tukey test were performed.
Results: There was no statistical interaction for the values of DC (p=0.067). For FS in MPa, CL produced the highest values in G1 (151.2) followed by SS (123.8) and PD (69.1). For all other groups there was no difference between CL and SS and PD showed the lowest values. Considering each photo-activation method separately, G1 showed the lowest values overall. For FM in GPa, G4 showed lowest values (4.7) in SS, while CL showed no difference in all groups.
Conclusions: The modulated methods, mainly PD, produced the lowest values of FS and FM. Composites with different filler ratios did not show different FM when photo-activated with CL, but the composite G3 usually showed the higher mechanical properties.