Color Stability Subject to Artificial Aging and Red Wine Discoloration

Objective: This study aimed to determine the color stability of different tooth colored filling materials. They were subjected to artificial aging by thermocycling (TC) and a severe discoloration challenge with red wine. Methods: 336 specimens of seven materials (Filtek Supreme^® (3MEspe), Ecusit^® (DMG), Filtek Z250^® (3MEspe), Herculite XR^® (Kerr), Durafill VS^® (Heraeus Kulzer), Ketac Fil^® (3MEspe) and DyractXtra^® (Dentsply) were fabricated. The specimen were randomly assigned to four groups: group one 5000 cycles TC, group two 2500 cycles TC, group three no TC, group four served as control and was stored in artificial saliva at 37 °C. Groups one to three underwent a wine/water/saliva cycle (storage for 15' in red wine, for 2' in tap water and the remaining time of 23h43' in artificial saliva for nine consecutive days). To differentiate between extrinsic and intrinsic stain, specimens were polished after the last discoloration cycle. CIE L*a*b* values, were taken at four intervals: at baseline, after TC, after discoloration cycles and after final polishing. A small-area colorimeter (ShadeEyeNCC®, Shofu) was used. ΔL, Δa, Δb and ΔE values were calculated to determine the extent of color change. Statistical evaluation (oneway ANOVA (Bonferroni), t-Test for (un)-paired samples) was performed using SPSS version 12.0. Results: Ecusit (ΔE 2.37±0.75) showed the least change in average color values in all four groups and was not influenced by artificial aging. It was followed by Filtek Supreme (ΔE 3.29 ±1.38). Both showed significantly lower values than all other investigated materials Ketac Fil (ΔE 7.87±4.44), Z250 (ΔE 4.92±1.93), Herculite (ΔE 4.67±2.47), Dyract (ΔE 7.37±3.49), and Durafill VS (ΔE 6.19±2.70) (p<0.05). The number of thermocycles significantly increased ΔE values for the last five materials (mean p<0.05). Conclusion: Color change after polishing the specimens revealed that the discoloration was mostly extrinsic. Intrinsic discoloration increased in some materials after artificial aging.