Effect of bleaching on staining susceptibility of resin composite restorative materials

Statement of the Problem: Effect of bleaching procedures on staining susceptibility of resin restorative materials is still questionable. Purpose: The aim of this study was to evaluate the staining susceptibility of restorative materials bleached with 20% carbamide peroxide home bleaching agent and subsequently immersed in coffee and tea. Materials and Methods: Forty-two disk-shaped specimens were fabricated for each of the resin composites (Filtek Supreme XT [3M ESPE, St. Paul, MN, USA], Ceram-X Mono [Dentsply, Konstanz, Germany], and Aelite All Purpose Body [BISCO, Inc., Shaumburg, IL, USA]). The baseline color values were measured with a spectrophotometer. The specimens of each restorative material were randomly divided into two groups (N = 21). While the first group specimens were stored in distilled water (nonbleaching group-control), bleaching agent (Opalescence PF 20% [Ultradent Poducts, South Jordan, UT, USA]) was applied on the top surface of each specimen of the second group (bleaching group). After color change values were measured, the specimens were randomly divided into three subgroups (N = 7) according to the staining solutions. The color change values (ΔE*ab) were calculated and the data were subjected to analysis of variance. Statistical significance was declared if the p value was 0.05 or less. Results: There was no statistically significant difference within each restorative material's ΔE*ab values after bleaching (p = 0.714). Also, the staining solutions did not cause a statistically significant difference between ΔE*ab values of bleaching compared with nonbleaching groups (p = 0.146). Significant interaction was found only between restorative materials and staining solutions (p = 0.000). Conclusion: Bleaching of the tested resin composites did not increase their susceptibility to extrinsic staining in vitro.