Color stability in a giomer, a conventional glass ionomer and a resin-modified glass ionomer exposed to different pigment beverages: An in vitro comparative study

Aim: Discoloration in ionomeric materials occurs by absorption of substances, so color stability is important because these materials are of choice to restore class V. The purpose of the current study was to evaluate the color stability of a giomer, a conventional glass ionomer and a resin-modified glass ionomer exposed to different beverages with different immersion times. Materials and Methods: This in vitro experimental and longitudinal study had 135 discs were sampled in total (2 mm thick x 8 mm in diameter) distributed in three equal groups (n = 45): Beautifil II, Vitremer, and Ketac Universal. Each group was divided into three equal subgroups (n = 15 each group) and immersed in three different staining solutions: coffee, Coca-Cola (R), and red wine. Color change was recorded with the Vita Easyshade (R) spectrophotometer after 1 h, 24 h, and 1 week of immersion. Measures of central tendency and dispersion were calculated. Kruskal-Wallis and Friedman nonparametric H tests were used to compare independent measures. The Bonferroni post hoc was used considering a significance level of P < 0.05. Results: Beautifil II (P <0.05) and Ketac Universal (P < 0.05) showed significant differences with respect to color variation (Delta E) when comparing exposure to Coca-Cola (R) versus exposure to coffee and red wine for 1 h, 24 h, and 1 week. Vitremer showed no significant differences when exposed to Coca-Cola (R), coffee, and red wine for 1 h, 24 h, and 1 week (P = 0.607, P = 0.276, and P = 0.134, sequentially). All three restorative materials, after 1 hour immersed in Coca-Cola (R), showed Delta E < 3.3 and Beautifil II obtained Delta E = 3.12 after 24 h immersed in the same beverage. Conclusion: Coffee and red wine significantly varied the color of Beautifil II and Ketac Universal over time. Beautifil II and Ketac Universal showed significantly more pigmentation with red wine and less with Coca-Cola (R) at 1 week immersion. Vitremer showed no significant differences when exposed to Coca-Cola (R), coffee, and red wine at all times tested. There were clinically acceptable variations for all three restorative materials immersed in Coca-Cola for 1 h. This clinical threshold was only maintained for the Beautifil II giomer up to 24 h of immersion in the same beverage.