Effects of Novel Finishing and Polishing Systems on Surface Roughness and Morphology of Nanocomposites

OBJECTIVES: The purpose of this in vitro study was to evaluate the effects of different finishing/polishing techniques on the surface roughness of nanocomposites after thermocycling aging. MATERIALS AND METHODS: Five contemporary resin-based composites (Clearfil Majesty ES-2, Filtek Z550, Estelite∑Quick, Zenit, Filtek Z250) were tested. For each resin-based composite, 50 disc-shaped specimens were prepared and groups were divided into five subgroups according to the finishing/polishing methods (n = 10): control, finishing/polishing brush, finishing/polishing disc, and two different finishing/polishing wheels. Before and after aging, the surface roughness of specimens was measured. For each treatment method two samples were analyzed using a scanning electron microscope. Two-way analysis of variance and paired samples t-tests were used to evaluate the data and the means were compared by Bonferroni tests (p ≤ 0.05). RESULTS: Before aging, the Filtek Z250 resin with the Mylar strip group showed the lowest surface roughness (Ra) value (0.13 ± 0.03 µm, p < 0.05) and the Clearfil Majesty ES 2 resin with Occlubrush finishing/polishing system showed the highest (0.7 ± 0.13 µm, p < 0.05). After aging, the Clearfil Majesty ES 2 resin with the Mylar strip group showed the highest surface roughness (Ra) value (0.96 ± 0.4 µm) and the Clearfil Majesty ES 2 resin with the Sof-Lex aluminum oxide disc finishing/polishing system showed the lowest surface roughness (Ra) value (0.25 ± 0.06 µm, p < 0.05). CONCLUSIONS: Composite type and finishing/polishing method significantly affected the surface roughness of composites before and after thermocycling aging. CLINICAL SIGNIFICANCE: There were significant interactions between finishing/polishing methods and composite types for surface roughness. The results give clinicians some flexibility in choosing appropriate finishing/polishing techniques for each resin composite material. (J Esthet Restor Dent 28:247-261, 2016).