Abstract
Background. This in vitro experimental study evaluated the color stability and effect of bleaching and re-polishing Gaenial, nanohybrid veneering composite resin material, following immersion in saffron, turmeric, and black pepper solutions.
Methods. Sixty disk-shaped composite resin samples were prepared and randomly assigned to four groups (n=15). The samples were immersed in saffron, turmeric, and black pepper solutions for seven days. Color parameters were assessed using a spectrophotometer before immersion and after seven days. Following immersion, one side of each sample underwent a bleaching treatment, while the opposite side was re-polished. Two-way ANOVA and independent t-test were used to evaluate the effectiveness of the bleaching and re-polishing procedures to remove stains from the composite resin samples. Data analysis was conducted using SPSS 17.
Results. The groups exhibited statistically significant differences (P<0.001). Turmeric solution showed the highest discoloration compared to the other two solutions, followed by saffron, with black pepper demonstrating the least stainability. In the saffron group, no statistically significant difference was observed between the bleaching and re-polishing treatments (P=0.06). Conversely, in the turmeric and black pepper groups, there were statistically significant differences between bleaching and re-polishing (P<0.001). In the control group, no statistically significant difference was found between the bleaching and re-polishing treatments (P=0.378).
Conclusion. The effectiveness of bleaching and re-polishing varied across the groups. In both the turmeric and black pepper groups, bleaching was more effective in reducing discoloration than re-polishing. Conversely, no statistically significant difference was found between bleaching and re-polishing treatments in the saffron group.