Background and Aim: The Color stability of composite resin materials is important for satisfactory restorative results. Discoloration of composite restorations can bring about patient dissatisfaction as well as long term failure of the restoration. The purpose of this study was to evaluate the effect of tea solution on color stability of 3 nanocomposites. 

Materials and Methods: In this experimental study 30 composite disks 8.5 mm in diameter and 2mm in thickness were made from the following composite materials: Grandio, Z350XT and Herculite XRV Ultra. The samples were assigned to 3 groups of 10 based on the composite material they were made of Half of the samples in each group (5 disks) were immersed in tea solution and the other half (5 disks) were submerged in pure water. Specimens were treated in selected solutions for 72 hours. Calorimetric assessment was done with a spectrophotometer before and after immersion in designated solutions. . Statistical analysis of the results were done using two-way ANOVA test.

Results: Measured discolorations for tested composites Z350XT, Grandio, and Herculite XRV were 1.62 ± 0.59, 2.46 ± 0.74, and 2.92 ± 0.72 respectively. The discoloration (ΔE) of all three composites after immersion in tea was significant (P=0.03) compared to initial colors However, it was within the clinically acceptable range (ΔE < 3.3). The Color change after immersion in pure water was not significant (P=0.1). 

 Conclusion: The highest level of discoloration belonged to Z350XT composite, and the lowest discoloration belonged to Herculite XRV Ultra