Effect of Hydrogen Peroxide-Based Bleaching Agents on the Color Dimensions and Surface Roughness of Different Milled Restorative Dental Materials.

To compare the color dimensions, color discrepancies (ΔE00), and surface roughness of milled materials before and after application of a bleaching agent. A total of 10 extracted molars were obtained. Each tooth was cut in transverse sections to create disks (3-mm thick, 10-mm diameter; control group). Disk specimens of eight materials (n &#61; 10 per group) were fabricated: polymethyl methacrylate (PMMA) interim material (PMMA-Telio group), two resin nanoceramics (RNC-Ultimate group and RNC-Cerasmart group), two hybrid ceramics (HC-Shofu group and HC-Enamic group), lithium disilicate (LD-Emax group), zirconia-reinforced glass ceramic (ZGC-Suprinity group), and zirconia (Zr-InCeram group). Color measurements were obtained using a spectrophotometer before and after applying 35% hydrogen peroxide-based bleaching agent. Pre- and postbleaching surface roughness (Sa) analyses were completed using a profilometer. Significant L*, a*, b*, and ΔE00 value differences were found (P < .05). Color discrepancies (ΔE00) ranged from 0.30 ± 0.14 to 4.82 ± 0.10. The highest color discrepancies were measured on the PMMA-Telio group, while the lowest color discrepancies were computed for ZGC-Suprinity, RNCUltimate, and RNC-Cerasmart. Significant surface roughness differences were found (P < .05). The largest increase of surface roughness values between the pre- and postbleaching measurements was obtained in the PMMA-Telio group with a mean ΔSa value of 4.73 ± 3.02, while the largest decrease of surface roughness values between the pre- and postbleaching measurements was obtained in the Zr-InCeram group with a mean ΔSa value of -1.58 ± 0.10. The milled materials showed significant pre- and postbleaching color and surface roughness discrepancies.