Objectives: The purpose of this in vitro study was to evaluate the influence of the ceramic thickness, cement shade, and airborne-particle abrasion of the titanium on the final color of titanium base cemented lithium disilicate glass-ceramic restorations.
Method and materials: In total, 144 lithium disilicate glass-ceramic disks of three thicknesses (0.5, 1.0, and 1.5 mm) were cemented to airborne-particle-abraded and non-airborne-particle-abraded titanium disks with six adhesive resin cements. The color measurements were performed with a clinical spectrophotometer. The mean and standard deviation of evaluated ΔE values were calculated. A three-way analysis of variance (ANOVA) was used for analyzing the data. Statistical analyses were computed with a significance level of α = .05 using a statistical software program (Minitab 17, Minitab).
Results: The 0.5- and 1-mm-thick ceramic specimens cemented with Panavia V5 Opaque showed the lowest ΔE values when cemented on both non-airborne-particle-abraded (5.62 ± 1.66, 3.15 ± 1.28) and airborne-particle-abraded (5.55 ± 0.86, 3.16 ± 0.49) surfaces, while the highest values were seen in the groups cemented with RelyX U200 A2 (29.22 ± 0.83, 17.23 ± 0.45) and Panavia V5 A2 (29.94 ± 1.17, 16.71 ± 0.44) on airborne-particle-abraded surfaces. For the 1.5-mm-thick ceramics, the lowest ΔE values were seen when Multilink MO 0 cement was used on non-airborne-particle-abraded surfaces (1.56 ± 0.29) and when Panavia V5 Opaque was used on airborne-particle-abraded surfaces (1.56 ± 0.66). The highest values were seen when RelyX U200 A2 (9.77 ± 1.13), PA2 (9.24 ± 0.25), and Multilink HO 0 (9.19 ± 1.33) were used on airborne-particle-abraded surfaces, and when Multilink HO 0 (9.61 ± 1.70) was used on non-airborne-particle-abraded surfaces. The 1-mm-thick ceramics cemented with Multilink HO 0 showed higher ΔE values (12.05 ± 1.99) for airborne-particle-abraded and non-airborne-particle-abraded (12.58 ± 1.06) than thinner (0.5 mm) or thicker (1.5 mm) ceramics.
Conclusion: Thinnest ceramic superstructures resulted in the highest ΔE values. Cements that mask the underlying color reflect their own shade under thin superstructures. Airborne-particle abrasion of titanium surfaces increases the grayish reflectance if cement shade does not have the color masking ability.
Keywords: adhesive cement, airborne-particle abrasion, color, custom abutment, titanium base
