In vitro Assessment of the Color Stability of Two Resin Composites

This in vitro study aims to evaluate the effects of thermocycling and immersion in common dietary colorants on the color stability of two resin composites. 80 disk-shaped specimens divided into 2 groups of 40 each, were prepared using a plexiglass mold with the desired dimensions, polished, and stored in 37°C distilled water for 24 h. Thermocycling (10,000 cycles) was applied to all specimens. Color shades were recorded before and after thermocycling, 24 h, 3 days, and 6 days after immersion in colorants. Thermocycling has shown fewer color changes than immersion in colorants. The omnichroma led to overall higher color changes than 3M Filtek Z350 when immersed in all the colorants. Within the limitations of this study, the following conclusions were drawn: Thermocycling slightly affects the color stability of resin composites compared to immersion in colorants. The staining ability of resin composites is affected by the composite's brand, the type of solution, and the duration of immersion. Omnichroma has shown less color stability over time (6 months) compared to Filtek 3M Z350 XT when immersed in different solutions.