ABSTRACT
Objectives: This study aimed to investigate the effect of common mouthwashes on the color change of a nanohybrid composite and its further stain susceptibility to Coke and coffee. Materials and Methods: One hundred and fifty composite discs were prepared and initial color values were measured using a spectrophotometer. The specimens were grouped based on the 24h exposure to common mouthwashes including Listerine, chlorhexidine, two types of fluoride mouthwashes (alcohol free and alcohol containing) as well as distilled water as control (N=30). The color change (ΔE1) values were calculated to show the amount of color change caused by mouthwashes. Subsequently, the specimens in each group were subdivided and immersed in the secondary colorant solution (coffee, Coke and, distilled water) for seven days. The total color change (ΔE total) values were obtained to show the stain susceptibility. Statistical analysis was conducted using ANOVA and Tukey's post hoc test. A P-value less than 0.05 was considered statistically significant. Results: The calculated ΔE1 of resin composite was significantly higher for all mouthwash groups than that of the control group; however, all were in the clinically acceptable range. Exposure to Listerine and distilled water caused more staining effects compared to other mouthwashes after immersion in secondary colorant solutions. Regardless of primary mouthwash type, coffee and distilled water caused the highest and the least total discolorations, respectively (P<0.001). Conclusion: All mouthwashes caused a clinically acceptable color change in resin composite; however, further stain susceptibility depended on the mouthwashes but was not higher than distilled water.
ABSTRACT
Introduction: In recent years, the use of bleach shade composite resins has increased due to the high esthetic demands. The aim of the present study was to investigate the masking ability and translucency of several bleach shade composite resins. Materials and Methods: In this in vitro study, 180 discs from 9 bleach shade composite resins of 5 brands (G-aenial Anterior, Gradia Direct, Charisma Diamond, Estelite Sigma Quick, and Renamel Microfill) in thicknesses of 0.5, 1, 1.5, and 2 mm were prepared. The color parameters of the specimens were measured in a CIE l ∗ a ∗ b ∗ system using a spectrophotometer. Masking ability and translucency parameters were calculated, and the influence of thickness, shade, and composite resin brand on these variables was analyzed using the Kruskal-Wallis and Mann-Whitney U tests. Results: Both masking ability and translucency differed significantly among groups (p < 0.001), but only MA was different between different brands (p < 0.001). Higher thicknesses showed lower translucency in all pairwise comparisons (p < 0.001). 0.5 mm-thick specimens had lower masking ability than 1.5 mm- (p=0.016) and 2 mm- (p=0.035) thick ones. However, masking ability of other thickness pairs did not show a significant difference (p > 0.05). G-aenial Anterior and Renamel Microfill had the highest and lowest masking ability. Bleach white shades had lower masking ability and higher translucency than extrawhite bleach shades. Conclusion: Translucency and masking ability of bleach shade composite resins differed in different thicknesses, composite resin brands, and shade groups.
