Effects of sports drinks on color stability of nanofilled and microhybrid composites after long-term immersion

Abstract

Objectives: This study assessed the effects of three sports drinks on the color stability of two nanofilled and two microhybrid composite materials after 1-month and 6-month periods.

Materials and methods: Twenty-eight disc-shaped specimens (diameter: 10mm and thickness: 2mm) each were made from four resin composites (Clearfil Majesty Posterior, Filtek Supreme, Clearfil APX, and Filtek Z250). All the specimens were stored in distilled water for 24h at 37°C. Then, the baseline color values (L*a*b*) of each specimen were measured using a spectrophotometer according to the CIEL*a*b* color scale. Seven randomly selected specimens from each composite material were then immersed in one of the three sports drinks (Powerade, Red Bull, and Burn) or distilled water (control) for 1 and 6 months. After each immersion, the color values of each specimen were remeasured, and the color change value (ΔE) was calculated. The data were evaluated using the Kruskal-Wallis and Mann-Whitney U-tests.

Results: The tested resin composites showed color changes over the 6-month evaluation periods. At 1 month, highest level of color changes was observed in the Clearfil APX specimens immersed in Burn (p<0.01). Clearfil Majesty Posterior showed less discoloration in all the composite materials tested after 6 months (p<0.001). Independent of the composite materials tested, Burn resulted in the highest level of discoloration after both immersion periods (p<0.01).

Conclusion: All the test solutions used in the present study caused greater discoloration than the clinically acceptable level of threshold (ΔE<3.3) over the 6-month evaluation period except for Clearfil Majesty Posterior immersed in distilled water (2.91±0.28). The effect of each solution on the color stability of the composite materials depended on the type of solution, exposure time, and composition of the composite material.

Clinical significance: The effect of a solution on color stability of composite materials depends on the type of solution, exposure time, and composition of the material. In clinical practice, patients should be aware of the staining effects and erosive potential of sports drinks if consumed a longer period of time.