The aim of this study was to evaluate the effects of staining solutions on the colour stability of self-cure provisional resin materials.
The specimens were prepared for each of three auto-polymerized bis-acryl resin and auto-polymerized methyl methacrylate provisional resin material. The baseline colour values were measured with a colorimeter according to the CIE L*a*b* colour scale. After the first measurement (T0), specimens were placed in staining solutions (coffee, coca-cola, burn and distilled water for control group) and the other measurements were taken after 24 h (T1), 1 week (T2) and 4 weeks (T3).
Data were analyze statistically by (a) repeated measures (ANOVA), (b) one and two way ANOVA, and (c) Tukey HSD multiple comparison tests. At the 24 h immersion period, the post hoc analysis indicated that AccessCrown-coffee revealed the highest ΔE* values (4.4). At the second immersion period (1 week), Structur2 SC-coffee had the highest ΔE* values compared with other materials (5.4).
The degrees of discoloration were increased with immersion time. The methylmethacrylate resin was more resistant to discoloration than bis-acryl resins. After immersion for 30 days, the coffee solution resulted in unacceptable discoloration for all the tested materials.