Abstract
A knowledge of color and surface roughness of denture base materials is important for achieving clinically successful complete dentures. The aim of this study was to evaluate the effects of different salivary pH values on color stability and surface roughness of heat cured, light cured and CAD/CAM fabricated denture acrylic resin materials. Thirty discs with dimensions of (10 x 3 mm) were fabricated from heat-cured, light-cured, and CAD/CAM denture acrylic resin materials. The color (.E) and surface roughness (Sa) were measured prior to the conduction of the experiment and after 30 days immersion in saliva using a Reflectance Spectrophotometer and non-contacting Profile-meter, respectively. All the acrylic resin specimens were subjected to brushing and thermocycling according to a standardized protocol. The discs of each type of acrylic resin materials were immersed and incubated in three different salivary pH values (acidic 5.7, neutral 7 and basic 8.3) for 30 days. Results were analyzed by two-way ANOVA followed by independent sample t-test for comparison. Both, the type of the acrylic resin material and the salivary pH value, have significant effects on color stability (.E) and surface roughness (Sa). Both heat cured and CAD/ CAM fabricated acrylic resin materials exhibited clinically acceptable color values (.E<3.3) regardless of the salivary pH value utilized for incubation, this was not apply for light cure acrylic (.E>3.3) after being subjected to acidic saliva pH (.E = 7.29). CAD/CAM fabricated acrylic resin material exhibited the least amount of surface roughness following incubation in different salivary pH values. The study concluded that CAD/CAM fabricated denture acrylic resin material might be the material of choice to construct dentures for patients known to have acidic dietary intake. It demonstrated clinically acceptable color stability and lower surface roughness values in comparison to the other denture acrylic resin materials.