Effect of traditional Korean fermented foods on the color stability of single-shade resin

Purpose: This study was to evaluate the effect of coffee and traditional Korean fermented foods on the color stability of singleshade resin compared to resin composites with a multi-shade system.Materials and Methods: Two esthetic composite resins were used: one nanofilled (FiltekTM Z350 XT universal A2 shade, 3M ESPE) and one supra-nanofilled (Omnichroma, single shade, Tokuyama Dental).A silicone mold (8 mm diameter, 2 mm thickness) was used to create the composite resin specimens.The resin was applied to the mold, covered with a mylar strip, and light-cured with an LED photopolymerizer (VALO Grand, Ultradent) for 40 seconds.All specimens were polished per manufacturer instructions and stored in distilled water at 37C for 24 hours.Baseline color measurements were taken using a spectrophotometer (Minolta CM-26d, Minolta Co.,) following the CIE Lab* system.Afterward, the specimens were divided into four groups (red pepper paste, soy sauce, coffee, and distilled water), and color changes (E) were measured at 1, 7, and 14 days.Independent samples t-test was used to determine if there was a difference in color change between composite resins.Kruskal-Wallis test was used to determine if there was a difference between solutions.Results: On Day 1, only the coffee group showed a significant color difference between the two resins, with Omnichroma exhibiting more color change.By Day 7, the soy sauce group also showed significant color differences in both Omnichroma and Filtek Z350 XT (P < 0.05), with color change increasing in all groups.Similar to Day 1, Omnichroma had greater color changes overall.On Day 14, there was a color difference between the two resins in the coffee and soy sauce groups, similar to Day 7.While the red pepper paste and distilled water groups showed more color change in Omnichroma, the differences were not statistically significant.Conclusion: Within the limitations of this study, when tested with coffee and traditional Korean fermented foods, Filtek Z350 XT demonstrated greater color stability compared to Omnichroma.Additionally, coffee caused more discoloration in the resin than the traditional Korean fermented foods.(