Comparison of two-step versus four-step composite finishing/ polishing disc systems: Evaluation of a new two-step composite polishing disc system

Objective: The purpose of this study was to evaluate surface finish and gloss of a two-step composite finishing/polishing (F/P) disc system compared with two multistep systems on five composites. Methods: Seventy-five disc-shaped composite specimens (D=10.0 mm, 2 mm thick, n=15 per composite) were made of microfill (Durafill-D), nanofill (Filtek Supreme-FS), nanohybrid (Premise-PR), and microhybrids (Filtek Z250-FZ, Esthet-EX). One side of each specimen was initially finished with a carbide bur. Five specimens of each resin composite were randomly assigned to receive full F/P by each of the disc systems: two-step (Enhance Flex NST-EF) and four-step (Sof-Lex-SL, Super- Snap-SS). Surface gloss was measured with a glossmeter and surface roughness was measured with a profilometer. Results were analyzed by two-way analysis of variance (ANOVA)/ Tukey's (α<0.05). Results: No difference in gloss was noted among the three F/P systems when used with D and EX; no difference between SL and EF when used with any composite, except for FS; and no difference between SL and SS when used with any composite. SL and EF showed similar surface roughness when used on all composites, except for EX. EF and SS showed similar surface roughness on PR. SL and SS showed similar surface roughness values on every composite, except for FZ. Conclusions: EF was capable of providing similar gloss and surface roughness to SL on four composites evaluated but was not able to produce as glossy or as smooth a surface as SS for three of the five composites.