The aim of this study was to evaluate the effect food-simulating media (FS) associated with toothbrushing (T) on color stability of different resin composites.
Methods:
Eighty specimens of each different composite brand (Grandio SO/Voco-G, Amaris/Voco-A, Z350 XT/3MEspe-Z, P90/3MEspe-P), 2mm thick and 2.8mm in diameter, were fabricated. For each material, the specimens were divided into four groups according to FS storage media: artificial saliva (AS), heptane (H), 0.02M citric acid (CA), 70% ethanol (E). The specimens were kept in individual vials with 2 ml of storage media at 37ºC for 7 days. The top surface of specimens were submitted to 10,950 brushing cycles (200g load) in an automatic toothbrushing machine with an abrasive slurry, simulating one year of clinical service. The specimens were immersed into 2mL coffee solution at 37ºC for 24 hour to simulate one month of consumption. Color measurements (ΔE) were obtained at baseline-B, after FS, after T, and after coffee storage-C, by means of spectrophotometry. Data were submitted to two-way repeated measures ANOVA and Tukey’s test (p<0.05).
Results: The mean ΔE values for composite brands were: P(3.36)a, G(3.75)ab, A(3.90)b, Z(5.39)c. The mean ΔE values for storage media were: AS(3.76)a, E(4.02)ab, CA(4.24)b, H(4.41)b. The mean ΔE values after each treatment were: B(3.52)a, T(4.26)b, FS(4.53)b.
Conclusions: The composite Z showed the highest color change. The toothbrushing procedure and the immersion in coffee influenced the color stability. The FS resulted in greater color variations for H and CA.