Color stability of reline resin after drinks immersion and disinfection

Objective: The aim was evaluate the effects of drinks on the color stability of reline resin after disinfection. Methods: Disks of acrylic resin (Lucitone 550) were made, relined with Tokuyama Rebase II and divided into 12 groups (n=10) according to the immersion solution: G1– water (control group), G1M– water and microwave disinfection (3min at 650W) once a week (MD), G2– coffee, G2M– coffee and MD, G3– tea, G3M – tea and MD, G4– cola, G4M– cola and MD, G5– strawberry juice, G5M– strawberry juice and MD, G6– grape juice, G6M– grape juice and MD. Each specimen was immersed in the solutions for 30min/day. Color parameters in L*a*b* were recorded by spectrophotometer, before immersion and after 7 and 15 days, 1, 3 and 6 months. Based on the L*a*b* values the color difference (ΔE) was calculated. Data were statistically analyzed by ANOVA, Kruskal-Wallis and Tukeyxs test (P=0.05). Results: Results showed significant differences between ΔE values of G5M and G4, G5M and G3, G5M and G1 after 7 days. When G3M and G3 were compared, G3M demonstrated higher ΔE values than G3 after 7 days. For G5M after 15 days, ΔE values were higher than those of G3. There was a significant difference between the G5M and G4 after 1 month. Immersion in strawberry juice and MD (G5M) for 1 month produced higher ΔE values than those of G4M. G5M was the combination that demonstrated significantly different ΔE values compared with G3 after 1 month. Comparisons between G6M and G1 after 6 months revealed significantly higher ΔE values for specimens of G6M. ΔE of test materials intensified with increasing storage interval. In the 92% groups, there was significant change color after 6 months when compared with 7 days. Conclusion: Tokuyama showed color's changing independent of drinks or long-term exposure to these staining agents.