In vitro comparison of color stability and surface roughness of bulk fill flowable composite and universal packable composite

Abstract

Background: Bulk fill composites have been introduced as restorative material, where they can be cured up to 4 mm thickness. In this research, we evaluated several flowable bulk fill composite material that can be used as anterior restorations, by testing color stability and surface roughness and compare them to the universal packable composite. Methods: 120 disc-shaped specimens were made from four composite materials shade A1: One universal packable composite (Filtek Z250 XT Universal), and three bulk fill flowable composite (G-aenial Flo X, Filtek Bulk Fill, SDR Plus Bulk Fill). Composite specimens were randomly divided into two groups according to the finishing and polishing system: Sof-lex discs, and Rubber stone system. The baseline color test was performed for each specimen, and the surface roughness was measured at three different points. Specimens were further divided equally and immersed in three different solutions (Distilled Water, Coffee and Cola). Readings were taken at three different time intervals: at the baseline, after 3 days, and after 10 days. Results: Comparing the tested materials in terms of color change, Kruskal Wallis test showed no statistically significant difference (p<0.05) among the composite materials immersed in same solution. On the other hand, Filtek bulk fill composite material presented the least surface roughness compared to the other materials. However, there were no statistically significant difference in surface roughness comparing the two polishing systems, except in SDR bulk fill flowable composite material which had less surface roughness with rubber stone system at the baseline. Conclusions: Within the limitation of our study, it can be concluded that there was no major difference in color change between materials regardless of other factors. The three used bulk fill flowable composites are not recommended as anterior restorations as they yield color change detected by the naked eye (∆E where ≥ 3.3).