Effect of staining beverages and bleaching on optical properties of a CAD/CAM nanohybrid and nanoceramic restorative material

BACKGROUND: The purpose of this study was to evaluate the optical properties of nanohybrid Grandio (GR) and nanoceramic Lava Ultimate (LU) CAD/CAM restorative materials subjected to different beverage solutions and subsequently bleached. METHODS: Five groups of each restorative material (n = 20/group, shade A2-high translucent) were immersed in distilled water, coffee, tea, cola, and ginger for one week. Changes in whiteness index, translucency parameter, and color changes of the specimens were evaluated. The data of color measurements after staining, bleaching, and the residual differences were statistically analyzed using Kruskal–Wallis and Mann–Whitney U tests at the significance level of P < 0.05. RESULTS: LU and GR revealed the highest differences in whiteness index after coffee staining (P < 0.001). GR revealed lower translucency parameter differences after staining with coffee than LU (P = 0.007). There were no significant differences in translucency changes between LU and GR after staining with tea, cola, or ginger (P > 0.05). LU revealed significantly greater color changes than GR after staining (P < 0.001). CONCLUSIONS: LU nanoceramic CAD/CAM restorative material revealed higher color changes than GR nanohybrid material. Staining beverage solutions had a distinct influence on the optical properties of the tested CAD/CAM restorative materials.