Method: For the study, seven composites were selected: Z250 (3M ESPE), Empress Direct (Ivoclar Vivadent), Charisma Diamond (Heraeus Kulzer), Opallis (FGM), Amelogen (Ultradent Inc.), Ice (SDI ) and Premise (Kerr Dental). The composites were subjected to successive baths of alcohol and acetone until complete removal of the organic content. To evaluate the morphology of the particles, the samples were mounted on metal stubs, coated with gold and observed under scanning electron microscopy (SEM) (VP 435, Leo). It was used five repetitions (n=5) of each composite resins to analyze the filler particles morphology and SEM images were taken at x1.000 and x5.000 magnifications. The measurement of filler sizes was performed using the scale markers of the figures. To determine the composition of the filler fraction (n=5), the samples were mounted on plastic stubs and covered with carbon for analysis by energy dispersive x-ray (EDX). Chemical elements were identified by using a SEM operating with a Vantage System (Noran Instruments). The spectra for EDX measurements were obtained for 100s livetime.
Result: EDX measurements showed high amount of silicon for all composites, which also presented aluminum. The composite Z250 showed spherical particles (1 to 2 μm) and silicon/zirconium elements. The other composites showed irregular shaped particles, with sizes ranging from 0.5 μm to 2 μm.
Conclusion: The dental composite resins showed different inorganic particles, which differed in composition and morphology, with silicon and aluminum in all composites.