Effect of staining agents on color change of composites

Resumo

Composite resins are materials that can present color
changing when exposed to pigments. Objective: The aim of this
study was to evaluate, in vitro, the color changing of composites after
immersion in different substances for different periods. Material and
methods: Two microhybrid composite resins: Charisma (Heraeus
– Kulzer) and Opallis (FGM) were used. Red wine and acai pulp
were also used as immersion medium. For this study, 32 specimens
with 10 mm of diameter and 2 mm of thickness were used, divided
into 4 groups: Group 1 – Opallis composite immersed in red wine
solution; Group 2 – Opallis composite immersed in acai berry
pulp solution; Group 3 – Charisma composite immersed in red
wine solution; Group 4 – Charisma composite immersed in acai
berry pulp solution. The specimens were evaluated in the following
time periods: T0 – baseline, T1 – 24 hours, T2 – 48 hours, T3
– 72 hours and T4 – 96 hours. For the assessment of staining, a
spectrophotometer for colorimetry was used (Color Guide 45 / 0, PCB
6807 BYK-Gardner Gerestsried GmBH, Germany), and the values
obtained were transferred to a computer and recorded according to
CIELAB system. Results: The data were evaluated using Kruskal-Wallis non-parametric tests with the following ���ΔE mean values for � �
the immersion periods of 24, 48, 72 and 96 hours, respectively:
G1 – 7.35, 7.84, 9.04,10.48; G2 – 2.92, 4.15, 4.30, 4.64; G3 – 3.14,
7.35, 8.13, 8.43, G4 – 4.49, 5.99, 6.92, 6.76. Conclusion: Red wine
showed a higher tendency toward altering the composite color than
acai berry pulp. In addition, no significant difference was found
concerning to the behavior of the two composite resins. Concerning
to the immersion time periods, significant differences were only
observed among the groups in the 24 hour time period.