Method: Experimental composites containing BisGMA, BisEMA, UDMA and TEGDMA as organic matrix were manipulated, with the camphorquinone/amine system as the initiator. For the inorganic filler (70%w/w), 4 different composites were investigated: only Ba-Al-SiO3 glass fillers (C1), Ba-Al-SiO3 glass/SiO2 90:10 (C2), Ba-Al-SiO3 glass/SiO2 80:20 (C3) and Ba-Al-SiO3 glass/SiO2 70:30 (C4). Thereafter, for the surface roughness measurement, cylindrical specimens (5mm diameter and 2mm thick, n=4) were built. The specimens were photocured using a LED Radii-cal for 40s. After 24 h, the SR was measured by roughness meter. For the UTS, hour-glass specimens were made (1mm2 of cross-section), and tested in tension, in a universal testing machine (0.5mm/min). Data were submitted to one-way ANOVA and Tukey’s test at a pre set alpha of 0.05.
Result: For the surface roughness measurement, all resin composites showed similar values (C1 – 0.400 ± 0.225; C2 – 0.640 ± 0.455; C3 - 0.332 ± 0.313; C4 – 0.585 ± 0.403). Therefore, when the UTS was evaluated, the experimental composite containing only glass fillers presented lower values compared to C2, C3 and C4 composites, which contained colloidal silica.
Conclusion:
The colloidal silica content increases the ultimate tensile strength and has no influence on the surface roughness of experimental methacrylate composites.