Color stability of denture resins after staining and exposure to cleansing agents

Statement of problem. Hard denture acrylic resins must maintain color stability to remain esthetic. Purpose. The purpose of this in vitro study was to measure the color stability of denture resins subjected to staining agents and cleaned with denture cleansers Material and methods. Forty-five disks (10-mm diameter, 2-mm thick) fabricated from 3 denture resins (light polymerized Eclipse; heat polymerized Lucitone 199 Heat; autopolymerized Lucitone 199 Repair) were stored for 24 hours in 37 degrees C water. After baseline colorimetry measurement were made, the specimens were soaked for 8 hours in a staining agent: coffee, cola, or grape juice. Subsequently, the specimens were soaked for 12 hours in a commercial denture cleanser (Polident, GlaxoSmithKline; Efferdent, Prestige Brands Inc) or water (control). This procedure was repeated every 24 hours. Staining agents and cleansers were replenished every 24 hours. Color change (Delta E) was determined after 2, 4, 6, and 8 weeks (n=5). Results were submitted to analysis of variance and Tukey honest significant difference test (alpha=.05). Results. Significant interaction was found between cleansers and staining agents (P=.006), cleansers and resins (P=.034), and resins and staining agents (P<.001). For the staining agent of grape juice, water allowed more discoloration (Delta E=16.93) than Efferdent (Delta E=14.41) or Polident (Delta E=1 4.81); Efferdent and Polident effects were not significantly different (P=.761). The Lucitone 199 Repair resin cleaned with water discolored more (Delta E=15.24) than with Efferdent (Delta E=14.14) or Polident (mean Delta E=13.82); the difference between Polident and Efferdent was not significant (P=.566). For Eclipse, grape juice discolored more (Delta E=1 6.43) than coffee (Delta E=1 2.23; P<.001) or cola (Delta E=1 3.78; P=.001); coffee and cola staining were not significantly different (P=.071). Conclusions. Eclipse resin stained most, especially in grape juice. Compared with water, Polident and Efferdent reduced discoloration better in Lucitone 199 Repair and grape juice stains. Nevertheless, discolorations in all 3 resins were perceivable, regardless of cleanser.