Comparative evaluation of color stability of three composite resins in mouthrinse: An in vitro study

AIM: The aim of this study was to compare the effect of chlorhexidine mouthrinse on the color stability between three different types of composites. MATERIALS AND METHODS: A total of 30 samples of size 10-mm length, 1-mm width, and 1-mm thickness were prepared on a customized microglass slide from each of the composite materials and immersed in 20 ml of distilled water followed by incubation at 37°C for 24 h. The samples were divided into three groups (n = 10) – Group I: A nanofilled composite, Filtek Z350XT (3M ESPE, St. Paul, USA); Group II: A microhybrid composite, Polofil Supra (Voco GmbH, Germany); and Group III: A nanoceramic composite, Ceram.x Sphere TEC (Dentsply, Konstanz, Germany). Baseline color values were recorded using a spectrophotometer (V-770 UV-Visible/NIR Spectrophotometer, Easton, Maryland, USA) according to the laboratory scale. After baseline color measurements, ten randomly selected specimens from each group were immersed in 20 ml of 0.2% chlorhexidine mouthrinse (Rexidin Plus, Aurangabad, India) for 24 h. The postimmersion color values of the samples were then recorded, respectively, using the same spectrophotometer. STATISTICAL ANALYSIS USED: The statistical analysis was done using one-way ANOVA followed by Tukey's post hoc test. RESULTS: Statistically significant difference was observed between the mean color change values in the three groups (P < 0.05) with the highest color change (delta E [ΔE]) in Group III (Nanoceramic composite). The ΔE for Group I (Nanofilled composite) was 3.16, Group II (Microhybrid composite) was 3.32, and Group III (Nanoceramic composite) was 3.51. CONCLUSION: All the three types of composites displayed color changes after immersion in mouthrinse, but the color shift depended on the material used, and the nanofilled composites (Filtek Z350XT, 3M ESPE, St. Paul, MN, USA) had higher color stability.