Reduced-step composite polishing systems - a new gold standard?

Objectives: To compare the surface gloss and surface roughness of three contemporary composites when polished with reduced-step polishing systems or a conventional multiple-step technique.

Methods: Fifty Discs (8mm ø x 2mm) were each fabricated from three composites; Essentia (ES), BRILLIANT EverGlow (EG), and Filtek Universal, (FU). 5 different polishing systems were randomly assigned 10 specimens from each composite group. The ‘gold standard’ multiple-step system consisted of Sof-Lex XT discs followed by DiaPolisher diamond paste (GC) (P1). The two-step systems were Polishettes (P2) and DIATECH ShapeGuard (P3) and the one-step systems used were; Opti1Step (P4) and OneGloss (P5). Surface gloss was measured using a glossmeter and surface roughness was measured by a profilometer. Statistical analysis was conducted using one-way ANOVA and Pearson correlation tests. Samples were also imaged across different length scales using scanning electron microscopy and macro-lens photography.

Results: The highest gloss was obtained when P2 and P3 were used in all composite groups (p<0.05). EG composite showed the lowest Sa (0.08 µm) when polished with P3 and highest gloss when polished with P2 (96.7 GU). Polishing with P5 resulted in highest Sa and lowest surface gloss in all composite groups (p<0.05). A high correlation was found between Sa and gloss, r = 0.73 (p<0.05). Both SEM and macro-lens photography supported quantitative data.

Conclusion: Both two-step composite polishing systems produced superior gloss compared to the traditional multiple-step polishing system. Mean surface roughness (Sa) and surface gloss are highly correlated with each other.

Clinical significance: Some reduced step composite polishing systems tested in this study produced superior gloss outcomes compared to the traditional gold-standard multi-step polishing system. This may enable significant clinical chair-time reduction and faster polishing protocols.