Effect of liquid polishing materials on the stainability of bis-acryl interim restorative material in vitro

Statement of problem. The discoloration of interim restorations may negatively affect a patient's perception of treatment. Purpose. The purpose of this study was to investigate the effect of liquid polishing materials on the color stability of bis-acryl interim restorative material. Material and methods. One hundred twenty specimens (10x2 mm) of a bis-acryl interim restorative material were divided into 3 groups. Group CO (control) was not subjected to any liquid polishing material. Groups GC and BC were polished with 2 liquid polishing materials. The specimens were then divided into 4 subgroups (n=10) and stored for 24 hours at 37 degrees C in different staining solutions: coffee, coffee with sugar, cola, and distilled water. The color of the specimens was measured at baseline and after immersion with a spectrophotometer by using the CIE L*a*b* system, and color changes (Delta E) were calculated. The means of color change for each specimen were analyzed by 2-way and 1-way ANOVA tests. Post hoc comparisons were made with the Tukey HSD and Tamhane T2 tests. Results. The application of liquid polishing materials significantly decreased the staining of autopolymerized bis-acryl interim restorative material (P<.01). Coffee with sugar resulted in higher Delta E values than coffee without sugar or cola. Conclusions. The use of liquid polishing materials significantly decreased staining when compared with bis-acryl specimens without liquid polish. The presence of sugar in coffee increased color change compared with coffee without sugar for all groups evaluated.