Color stability of nanohybrid resin-based composites, ormocers and compomers

The aim of this study is to evaluate the color stability of two nanohybrid resin-based composites, two organic modified ceramic resin composites (ormocers) and a compomer, following their immersion during 4 weeks in four usual drinks.

Forty discs of each of the following materials were prepared: GrandioSO (GR), Esthet X (EX), Dyract EXTRA (DY), Ceram X duo (CX), and Admira Fusion (AD). The discs were polished and stored in distilled water during 24 h at 37 °C. Color according to the CIEL*a*b* scale was recoded. Ten randomly selected samples of each material were immersed in red wine (RW), coffee (CF), cola (CK), and distilled water (DW). The color was recorded after 1, 7, 21 and 28 days of immersion. The ΔE values between the baseline color and each of the study timepoints were calculated. The data were analyzed based on the Kruskal-Wallis test, Wilcoxon test, and Mann-Whitney U test.

After 1 day of immersion, all the materials showed ΔE > 3.3, except EX, CF, and CX in CK. RD was the most staining beverage (ΔE 15.36 to 31.09). EX and CX were significantly less stained than the rest of the materials (p < 0.05).

All the staining solutions produced darkening beyond clinically acceptable limits. EX and CX were the materials who experimented less staining, followed by GD. AD and DY were the materials more stained. RW was the drink that produced more staining, followed by CF and CK.

After 24 h of immersion in all the solutions, equivalent to 1 month of exposure in the mouth, the evaluated materials showed clinically unacceptable ΔE values.