Objective: This study investigated the effect of prolonged soaking in the Kawa Daun beverage on the discoloration of nanofilled composite resin. Materials and methods: Thirty disk-shaped specimens (6 mm diameter, 2 mm thickness) of nanofilled composite resin were prepared and divided into six groups. The samples were soaked in Kawa Daun solution, Robusta coffee solution, and artificial saliva for 6 and 18 hours at 37°C. Color measurements were taken before and after soaking using a Colorflex EZ spectrophotometer, and ΔE values were calculated. Data were analyzed using repeated-measures analysis of variance and post-hoc tests (p < 0.05). Results: Significant color changes were observed among the groups (p < 0.001). Soaking in Kawa Daun and Robusta coffee solutions produced significantly greater discoloration than artificial saliva, with increased ΔE values corresponding to longer soaking times. Conclusion: Prolonged exposure to Kawa Daun beverage caused measurable discoloration of nanofilled composite resin, likely due to pigment and acid content that degrade the resin matrix. These findings highlight the importance of patient education regarding the esthetic effects of traditional acidic and pigmented beverages on dental restorations.
Mona et al. (2026) studied this question.