Evaluation of color stability and effect of bleaching and re-polishing procedures on saffron and turmeric and black pepper stain removal from anterior composite veneering material

Abstract

Background: One of the major disadvantages of composites is discoloration and changes of color after prolonged exposure to the oral environment. This in vitro experimental study evaluated the color stability and effect of bleaching and re-polishing of one brand of nanohybrid veneering composite materials ​( Gaenial, junior enamel) after immersion in three solutions of saffron ,turmeric and black pepper and distilled water uesd as a control group. Materials and Methods: 60 samples of disk-shaped composites with dimentions of 2mm × 6mm were prepared and randomly divided in to 4 groups that each group had 15 samples (including control group). Samples were immersed in solutions of saffron and turmeric and black pepper for 7 days period. Color parameters were assessed using a spectrophotometer before immersion and after7 days. After 7 days one side of all samples were bleached and the other side were re-polished. Once more color parameters were assessed with spectrophotometer and results were analyzed with ANOVA using SPSS23 software. Results: One-way ANOVA analysis and tukey test was used to evaluate color stability of nano composite (G aenial , junior enamel) . According to the results there were statistically significant difference between groups (P<0.001). Turmeric solution had the highest mean of discoloration when compared to other two solutions. In next rate of stainability was saffron solution and the last one was black pepper solution. Two-way ANOVA and independent T test were used to evaluate the effectiveness of bleaching and re-polishing procedures to remove stain from the composite. According to the results in saffron group there was not statistically significant difference between Bleaching and Re-polishing (P=0.06). In turmeric and black pepper groups there were statistically significant difference between Bleaching and Re-polishing (P <0.001). How ever, in control group there was not statistically significant difference between Bleaching and Re-polishing (P=0.378).

Conclusion: The initial color change was significant in different groups. Turmeric showed maximum discoloration. In the next rate of discoloration was saffron and black pepper. Effect of bleaching and re-polishing on color difference was different. In turmeric and blackpepper group there was significant different between re-polishing and bleaching groups and the bleaching was more effective than repolishing. In saffron group there was not statistically significant difference between Bleaching and Re-polishing