Effect of different beverages on color stability of resin composites

Objective: The aim of this study was to compare the color stability of nanofilled, nanohybrid and microhybrid resin composites immersed in common beverages in Thailand. Method: Fifty two disc-shaped resin composites (15 mm diameter and 1 mm thickness) were prepared from each of a nanofilled (A3 Filtek™ Z350XT; 3M ESPE, USA), a nanohybrid (A3 Filtek™ Z250; 3M ESPE, USA) and a microhybrid (A3 Premise™; Kerr cooperation, USA.) resin composites. The specimens were divided into four groups according to the beverages. All specimens were immersed in four types of solutions: Cola (Thainamthip, Thailand), green tea (Oishi trading, Thailand), black coffee (Nescafe, Thailand) and distilled water (as a control) and then stored at 37°C for 24 hours. The color of each specimen was measured before and after immersion by a colorimeter (ColorFlex®, Hunter Associates Laboratory Inc., USA) using CIE L*a*b* system and color change (Delta E) was then evaluated. The data were compared and analyzed using One-Way ANOVA (p<0.05). Results: The color differences of Cola and green tea groups were not different from water group. However, three types of resin composites immersed in black coffee had the greatest color change compared to other drinks (p<0.05). There was no statistically significant difference in discoloration among three types of resin composites. Conclusion: Within the limitation of this study, Cola and green tea did not influence the color stability of resin composites. Black coffee provided the highest discoloration.