Evaluating the Effect of Different Polymer and Composite Abutments on the Color Accuracy of Multilayer Pre-Colored Zirconia Polycrystal Dental Prosthesis

Abstract

With increasing aesthetic awareness and emphasis on time costs in today’s society, monolithic multilayer precolored zirconia ceramics (M-Zr) facilitate aesthetic restorations in a convenient and straightforward manner without the need for veneering porcelain to modify the color. However, the effect of abutment materials on the final color of M-Zr remains unclear. Herein, we placed Vita A1 Shade M-Zr on six different abutment materials, zirconia (Y-TZP), 3D printed composite resin (CR), dental model resin (MR), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), and cobalt–chromium alloy (Co–Cr), to evaluate their effect on the color accuracy of M-Zr. The color attributes (L*, a*, and b*) were measured using a dental spectrophotometer. The translucency parameter (TP), contrast ratio, color difference (ΔE) between each background substrate and the Vita A1 Shade Guide, and chroma values (C) were calculated to evaluate the color accuracy of M-Zr. A statistical analysis was performed using one-way analysis of variance and post hoc Tukey’s HSD tests (α = 0.05). The experimental results indicate that the TP values and contrast ratio of the M-Zr samples were 14.85 and 0.83, respectively. Co–Cr had the highest ΔE (6.08) and lowest C value (7.52); PEKK had the lowest ΔE (2.60), and PEEK had the highest C value (12.23) (p < 0.05). Notably, the ΔE values of CR (3.13), PEEK (2.86), and PEKK were within clinical indicators (ΔE < 3.7). Based on these results, it can be concluded that the abutment material has a significant effect on the final color of the M-Zr, and PEEK or PEKK resulted in good color accuracy. When choosing the dental MR, traditional zirconia, or metals as abutment materials, colored or opaque cement might be required to eliminate color distortion and achieve desirable optical properties.

Innovation Glass-Ceramic Spray Deposition Technology Improving the Adhesive Performance for Zirconium-Based Dental Restorations

“…Computer-aided design/manufacturing (CAD/CAM) is widely accepted by dentists and dental technicians because of its precision and efficiency [ 7 , 8 ]. As the requirements of the fully digital workflow, accompanied by oral scanning, have increased, the demand for multilayer transparency and gradient-color “monolithic zirconia restorations” that do not require veneering has increased [ 8 , 9 , 10 ]. The main weaknesses of zirconia are its unsatisfactory clinical bonding performance and evidence from long-term follow-up studies showing that the bond between zirconia and dental cement is poorer than that of lithium disilicate (LD) glass-ceramics [ 11 , 12 ].…”

Comparison of shear bond strength and color reproduction of two different high-performance polymers veneered with two different thicknesses of resin composite: an in-vitro study

“…Hsu et al [28] showed that using PAEK (PEEK & PEKK), as a substrate material was deduced to have the best color accuracy (ΔE < 2.9), among all the specimens tested in the present study. The results of various color attributes show that PAEK materials have a better color balance, higher color saturation, and lower hue compared to those of the other groups.…”

Effect of CAD/CAM Position and Thickness of Ultra-Translucent Multilayered Zirconia on Color Aspects

“…Several studies have reported that the final color of highly translucent zirconia is influenced by the background color. For instance, Hsu et al [ 37 ] and Tabatabaian et al [ 38 ] indicated that different abutment colors provided different TP and ΔE values as well as color attributes. Consistent with these findings, various research has suggested a minimum thickness of 1 mm for color accuracy on a light color background and a minimum thickness of 1.5 mm for the optimal masking ability [ 15 , 39 , 40 ], consistent with the results of this study which determined distinct color attributes at 1 mm thickness compared to other thicknesses.…”