Hardness and surface roughness of differently processed denture base acrylic resins after immersion in simulated gastric acid

The effect of gastric acid on the surface properties of denture base acrylic resin is unknown. The purpose of this in vitro study was to evaluate changes in the surface roughness and hardness of denture base acrylic resins after immersion in simulated gastric acid. Acrylic resin specimens (n=10) were prepared with 3 different processing techniques (compression-molded, injection-molded, and computer-aided design and computer-aided manufacturing [CAD-CAM] milled) and exposed to either gastric acid or artificial saliva (control). Surface roughness and hardness were measured at baseline (T0) and after 24-hour (T24) and 96-hour (T96) immersion in the solutions. The surface roughness and hardness data were analyzed by 3-way ANOVA and the Tukey HSD test (α=.05). At T24, the greatest change in surface hardness was observed for compression-molded specimens in gastric acid (P