Effect of Reduced-Step Polishing Systems on Color Stability of Nanocomposites Submitted to Thermocycling Staining with Common Beverages - An In Vitro Study.

Context: Long-term color stability of composite resins is one of the most important factors influencing the clinical longevity of aesthetic restorations.

Aims: This study evaluated the effect of novel reduced steps and gold standard multiple steps polishing systems of two composite resins; a nano-filled (Filtek Z350XT) versus a supra-nanofill (Palfique LX5) on their color stability after submitting to thermocycling with common beverages.

Materials and methods: Sixty disc-shaped specimens were fabricated from both composite resins (n = 30). From each material, ten specimens acted as the control group (Mylar strip), ten specimens were polished with Sof-Lex Diamond spirals, and ten were polished with Super-Snap X-Treme discs. All the specimens were thermocycled with staining solutions. Color was measured by a spectrophotometer before and after thermocycling and color difference (ΔE*) was calculated.

Statistical analysis used: One-way analysis of variance followed by Tukey's post-hoc test and independent t-test (α = 0.05) were used.

Results: A significantly highest color change was recorded for both control subgroups (P < 0.05), and the Sof-Lex Diamond spiral showed significantly the lowest color change (P < 0.05). Both the control and Sof-Lex Diamond spiral subgroups of Palfique LX5 produced significantly lower color change compared with subgroups of Filtek Z350 (P < 0.05).

Conclusions: Sof-Lex Diamond spiral polishing system provided the least color difference for both composites, while there was no significant difference between the materials when the Super-Snap X-Treme polishing system was used.