Color stability of recent composite resins

The objective of the study was to evaluate the color stability of 8 recently developed resin composites when exposed to various staining agents. Six disc-shaped specimens made out of 8 resin composite materials were immersed in artificial saliva, coffee, coke, tea, orange juice and red wine. The initial color (T0) of the 288 specimens was assessed by a calibrated reflectance spectrophotometer (SpectroShade, MHT) over a black as well as a white background. All specimens were kept in an incubator (INP-500, Memmert GmbH) at 37\ua0\ub0C for 4\ua0weeks. Colorant solutions were changed every 7\ua0days to avoid bacteria or yeast contamination. After 4\ua0weeks of storage in the colorants (T1), spectrophotometric measurements were repeated and \u394E00 was calculated. When analyzed over a white background, the mean \u394E00 values varied from 1.5 (Venus Diamond) to 52.4 (Miris 2). When analyzed over a black background, the mean \u394E00 values varied from 0.8 (Venus Diamond) to 40.0 (ELS). Significant differences were detected when comparing values at T0 and T1 (\u394E00) for both backgrounds (Anova and Fisher's LSD post hoc test). Resin composite materials do behave in a significantly different way (p value\ua0<\ua00.01) when exposed to various staining solutions