Color stability of denture acrylic resins and a soft lining material against tea, coffee, and nicotine

Abstract

Purpose: The purpose of this study was to investigate the effect of four solutions [saliva (control group), saliva+tea, saliva+coffee, saliva+nicotine] on the color of different denture base acrylic resins (heat-polymerized, injection-molded, autopolymerized) and a soft denture liner.

Materials and methods: Twenty specimens from each type of test material were prepared (2.5 mm diameter, 2 mm thickness). Five specimens from each test material (heat-polymerized, chemically polymerized, injection-molded acrylic resin, soft denture reliner) were stored in each solution in 37 degrees C in a dark environment. Colorimetric measurements were done on the 1st, 7th, and 30th days. Color differences among specimens immersed in saliva (control group), and staining solutions were evaluated over time. Data were statistically analyzed with one-way analysis of variance (ANOVA) (alpha= 0.05). ANOVA was followed by Tukey test to find which groups differed from each other.

Results: Significant color shifts occurred in heat-polymerized and injection-molded acrylic resins in coffee and in soft liner in nicotine over time (p < 0.05) (DeltaE > 1). The color shift of soft liner in nicotine was significantly different than that of the remainder of the test materials in nicotine (p < 0.05). The color shift magnitudes of each test material in coffee and tea were not significantly different when compared among the test material groups (p > 0.05).

Conclusions: The effect of staining solutions on the color of each test material in each session was perceivable by the human eye (DeltaE > 1); however, the color shifts of all test materials were clinically acceptable (DeltaE < 3.7) except for soft liner in nicotine, which was not clinically acceptable over time. Therefore, minimizing drinking of such beverages and use of tobacco, particularly when soft liner is applied, may be advantageous for denture wearers for long-term color stability.