Comparative Evaluation of Color Stability between Three Different CAD/CAM Milled Denture Base Materials: An In Vitro Study

摘要

Purpose to compare the color stability of Polyetheretherketone (PEEK), Acetal resin (polyoxymethylene POM) and Acrylic resin (Polymetylemethacrylate PMMA) denture base material discs milled by CAD/CAM and stored in different storage media. 63 specimens in the form of discs with 12mm diameter and 2 mm thickness were CAD/CAM milled and divided according to the denture base material into 21 specimens for each group. Group I Polyetheretherketone (PEEK), group II Acetal Resin (polyoxymethylene POM), Group III Acrylic resin (Polymetylemethacrylate PMMA). Then specimens were divided equally into 3 subgroups (n= 7) according to the media in which the specimens stored into: coffee subgroup, ginger subgroup and distilled water as a control subgroup. A spectrophotometer was used to evaluate and measure color changes of each sample before storage and after 7 days, then color changes (ΔE) were calculated. It was found that, all materials revealed statistically significant color changes after stored for 7 days in different storage media. In all storage media, Group III (Acrylic resin) recorded the highest statistically significant color changes mean values, followed by Group I (PEEK) mean values, while the lowest color changes mean values were for Group II (Acetal resin). It was also found that coffee stained subgroups recorded higher color changes mean values than ginger stained subgroups. The CAD/CAM milled acetal resin denture base material demonstrated the highest color stability while Acrylic resin denture base material demonstrated the least color stable material. It was also found that coffee demonstrated the highest color changing storage media.