Composite resin color stability: Influence of light sources and immersion media

Objective: this study evaluated the influence of light sources and immersion media on the color stability of a nanofilled composite resin. material and methods: conventional halogen,high-power-density halogen and high-power-density light-emitting diode (led) units were used. there were 4 immersion media: coffee,tea,coke® and artificial saliva. a total of 180 specimens (10 mm × 2 mm) were prepared,immersed in artificial saliva for 24 h at 37±1°c,and had their initial color measured with a spectrophotometer according to the cielab system. then,the specimens were immersed in the 4 media during 60 days. data from the color change and luminosity were collected and subjected to statistical analysis by the kruskall-wallis test (p<0.05). for immersion time,the data were subjected to twoway anova test and fisher's test (p<0.05). results: high-power-density led (δe=1.91) promoted similar color stability of the composite resin to that of the tested halogen curing units (jet lite 4000 plus - δe=2.05; xl 3000 - δe=2.28). coffee (δe=8.40; δl=-5.21) showed the highest influence on color stability of the studied composite resin. conclusion: there was no significant difference in color stability regardless of the light sources,and coffee was the immersion medium that promoted the highest color changes on the tested composite resin.