Effect of Bleaching After Staining with Coffee on Color Stability of Single-Shade Universal Composite Resins

Objectives: The aim of this study was to evaluate the effect of office-type bleaching agent on the color stability of single-shade universal composite resin samples after storage in coffee solution.Materials and Methods: In this study, five single-shade universal composites, Omnichroma (Tokuyoma Dental, Japan), Vittra APS Unique (FGM Dental Group, Brazil), Zenchroma (President Dental, Germany), Charisma Diamond One (Kulzer, Germany), and Essentia Universal (GC, Japan) were used. A total of 50 samples were prepared (n=10) by creating cylindrical cavities with a diameter of 6 mm and a thickness of 2 mm on acrylic teeth. For staining procedure, samples were immersed in a coffee solution (Nescafe Classic, Nestle, Türkiye) for 14 days. Opalescence® Boost Office Teeth Bleaching (40% HP) was used for the bleaching treatment of the stained composite samples. ΔE00 color values were measured with spectrophotometer (VITA EasyshadeAdvance, Vita) in 3-time intervals (initial, after staining, and after bleaching). Data were evaluated with One-way Anova test.Results: As a result of the measurements, the ΔE00 values of all five composite resin groups between the initial and after staining were found to be greater than 1.8. Color difference between the after bleaching and after staining values was highest in the Zenchroma (President Dental, Germany) group, while it was lowest in the Essentia Universal (GC, Japan) group. The ΔE00 change between the initial and after bleaching values was observed to be less than 1.8 for all five composite resin groups.Conclusion: Office-type bleaching procedures are effective methods for significantly reducing the discoloration caused by solutions such as coffee, leading to lightening of the color in stained single-shade universal composite resins.