Method: Disk-shaped samples were fabricated out of 8 materials (5 CAD/ CAM and 3 direct composite materials). Samples were stored in distilled water for 24 hr at 37°C in an incubator (INP-500, Memmert), than randomly divided into five groups (n= 8) according to the different staining solutions (distilled water, tea, red wine, coffee and artificial saliva). Initial L*a*b* values were assessed by calibrated spectrophotometer against white and black background. Samples were immersed in staining solution and stored in an incubator at 37°C for 60 days. The test solutions were replaced every 12 days to avoid bacteria and yeast contamination. Before the color measurements, samples were rinsed for 60 s with a high-pressure hot-water airbrush and air dried. L*a*b* values were assessed again after 60 days of staining and values were recorded and deltaE values were calculated. ANOVA, and Tukey test were used to specifically identify differences between groups a = 0.05.
Result: Significant differences were detected by ANOVA (p=0.000) for deltaE values against black and white backgrounds. Red wine proved to have the highest staining potential followed by coffee, tea, artificial saliva and distilled water. Filtek Supreme XTE was the least color stable among the materials tested. Enamic showed better color stability than Vita MK II. Filtek Silorane showed an intermediate result between the CAD/CAM materials and the other direct composites.
Conclusion: Both, ceramic and composite CAD/CAM materials had a lower staining susceptibility than direct composites. Staining intensity was highly affected by colorants.