This evaluated the arrangement of filler particles in depth of nanocomposites, and surface roughness, wettability, microtopography, and micromorphology following additional polishing step. Forty samples of each composite tested [Filtek Z350XT (FZ), IPS Empress Direct (IP)] were fabricated and finished/polished/additionally polished using one of the following methods (n = 10/group): no finishing/polishing (NFP), Sof-Lex Pop-On + no additional polishing (SP), Sof-Lex Pop-On + Astropol rubber polisher (SP+A), and Sof-Lex Pop-On + felt disc with polishing paste (SP+FP). Surface roughness (Ra) and contact angles were measured using a profilometer and goniometer, respectively. Microtopography and micromorphology were evaluated using atomic force microscopy and scanning electron microscopy, respectively. Ra and contact angle data were examined by two-way analysis of variance and Tukey's test (p < .05). Organic matrix, lower and larger filler particles were disposed in depth. Mean Ra values were lowest and contact angles were smallest in the NFP group for both composite resins. SP+A and SP+FP decreased mean Ra in comparison with SP for FZ, whereas only SP+FP decreased mean Ra in comparison with SP for IP. Only SP+FP increased contact angles in comparison with SP for FZ, whereas contact angles in the SP+A, SP+FP, and SP groups were similar for FZ. Both composites presented more uniform topography and smother surfaces following SP+A and SP+FP in comparison with SP. Therefore, additional polishing improved surface smoothness and decreased wettability of the composite resins studied. SP+FP produced smoother and less wettable surfaces for FZ and IP.
Keywords: composite resin; dental polishing; surface roughness; wettability.
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