Effects of organic-inorganic hybrid coating on the color stability of denture base resins

Statement of problem. Denture base resin may be exposed to different conditions for long periods, resulting in varying degrees of staining, discoloration, and distortion. Purpose. The purpose of this in vitro study was to evaluate whether an organic-inorganic hybrid coating for base resins can improve color stability and reduce water absorption and solubility. Material and methods. An organic-inorganic hybrid coating was prepared, and resin sheets made from 4 types of base resin materials were divided into an experimental group (surface coating) and a control group (without coating). The water absorption and solubility in each group were tested. The resin sheets were immersed in tea, red wine, coffee, and cola. The color change (Delta E values) of resin sheets in different soaking solutions was evaluated at 1, 7, and 28 days. Results. Statistical analysis showed that water absorption and solubility in the experimental group were significantly lower than in the control group (P<.05). The 4 staining solutions (tea, red wine, coffee, and cola) caused base resin discoloration in a time-dependent manner. This staining and discoloration was also influenced by the type of resin material. About 85% of Delta E values in the experimental group were significantly lower than those in the control group (P<.05). At 28 days, almost all Delta E values in the experimental group were significantly lower than those in the control group (P<.05). Conclusions. The organic-inorganic hybrid coating effectively reduced the water uptake and solubility of base resins and significantly improved the color stability of the denture base.