Color stability of Vita classical shade guide after artificial accelerated aging

Statement of problem: If there is a noticeable color alteration in the shade guide, the result will be improper shade selection and consequently an unacceptable esthetic restoration. The effect of different weathering conditions on shade guides is still unclear.Purpose: The purpose of this study was to determine the effect of artificial accelerated aging on the color stability of Vita classic shade guide.Material and methods: The color parameters of the Vita classical shade guide tabs (n=160) were calculated before and after artificial accelerated aging (AAA) in a weathering machine using a spectroradiometer based on the CIE L*a*b* system. L*, a*, and b* coordinates and ΔE* were statistically analyzed using one-way analysis of variance followed by Bonferroni test (α=.05).Results. There was a statistically significant difference for L*,a*, and b* coordinates for all specimens, creating darker specimens with a decrease in the L* coordinate value (P<0.001), and more reddishyellowish specimens with an increase in a* and b* coordinate values (P<0.001). Conclusion: Color changes were observed in all shade tabs after accelerated aging.Clinical implications: Dentists should be aware of their shade guides after one year clinical service to achieve more esthetic results.