The present work shows the characterization of photoactivated composites, demonstrating that EPR spectroscopy combined with conventional analyses, can carry important information on the polymerization process of dental composites. Initially eight commercial composites were used, giving emphasis for the Z100 (3M ESPE) and the resin Opallis (FGM), irradiated by a LED unit (ULTRA BLUE - Dabi Atlante). Analyses for Electron Paramagnetic Resonance Spectroscopy, mechanical resistance, surface microhardness, gas picnometry, scratching, translucency measurement and Scanning Electron Microscopy (SEM) were accomplished. Based on the EPR results it was possible to identify the present radicals species and their relative intensity. Comparing the analyses accomplished for the two commercial brands, the results indicated that the resin Z100 (3M ESPE) generated a larger number of radicals (Ir = 2.40 u.a) when compared to the other resin (Ir = 1.00 u.a); also presented better performance when compared with other techniques used in the present manuscript, corroborating with the fact of composite which genterated larger number of radials as also the better physical properties.
Composites; mechanical performance; free radicals; EPR; photoactivation
