Effect of energy drinks on the color stability of nanofilled composite resin.

OBJECTIVE To study the effect of three energy drinks on the color stability of nanofilled composite resins after different periods of aging time. MATERIALS AND METHODS Composite resin disks, 6 mm diameter, 3 mm thickness were prepared from Filtec Z350 XT, Tetric EvoCeram, and Filtec Z250 XT. Specimens from each material were tested after aging with Red Bull, Bison and Power Horse energy drinks and distilled water as a control. Specimens were stored at 37°C in dark containers for 1, 7, 30 and 60 days. Color was assessed in the CIELAB using a colorimeter before and after each storage period. Color differences ΔE*ab and Δb* among specimens were measured. Mean values were statistically analyzed using one-way analysis of variance (ANOVA), with p < 0.05 as significance level. RESULTS The color change ΔE*ab and Δb* occurred by Red Bull, Bison and Power Horse energy drinks was significantly different for all tested materials at all four times p < 0.05 except in the Red Bull group. All specimens showed increase in color changes toward yellowness Δb* after a period of 1, 7, 30 and 60 days. The highest total color difference ΔE*ab was found in the Red Bull group after 60 days. CONCLUSION Energy drinks used in this study had staining effect on the tested composite resin materials. The discoloration increased with aging time toward yellowness; however, it was not perceptible in all test groups after 60 days.