PDF herunterladen
Open Access
CC BY 4.0 · Eur J Dent
DOI: 10.1055/s-0045-1806929
Original Article

Color Characteristic Alteration of Different Yttrium Oxide-Containing Multilayer Partially Stabilized Zirconia at Different Sintering Rates

Authors

  • Atthasit Boonbanyen

    1   Division of Biomaterials and Prosthodontics Research, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand

  • Niwut Juntavee 

    2   Department of Prosthodontics, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand

  • Apa Juntavee 

    3   Division of Pediatric Dentistry, Department of Preventive Dentistry, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
Weitere Informationen
Auch verfügbar auf
  Lizenzen und Reprints
Preview

Abstract

Objectives

Sintering influences the optical properties of zirconia. This study examined the effect of altering sintering rates on color characteristics of 3, 4, and 5 mol% yttria (Y)-containing multilayer zirconia.

Materials and Methods

A total of 135 specimens (width × length × thickness = 11.2 × 20 × 1.5 mm) were prepared from multilayer (cervical [C], middle [M], and incisal [I]) 3Y, 4Y, and 5Y zirconia, and randomly sintered at regular (RS: 10 °C/min), fast (FS: 35 °C/min), and speed (SS: 70 °C/min) sintering (n = 15/group). Translucency parameter (TP00), contrast ratio (CR), opalescence parameter (OP), and color difference (∆E00) were evaluated with the CIEL*a*b* system. Microstructure, crystalline (monoclinic [m], tetragonal [t], and cubic [c]) phases, and surface roughness (Ra) were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and 3D-digital topography.

Statistical Analysis

ANOVA and Bonferroni comparisons were determined for significant differences (p < 0.05).

Results

Significant differences in TP00, CR, OP, and ∆E00 of zirconia types, layers, sintering rates, and their interactions were indicated (p < 0.05). Significant increases in TP00 and ∆E00, but decreases in CR and OP, upon rising the amount of Y (5Y > 4Y > 3Y), region (I > M > C), and speed sintering (SS > FS > RS) (p < 0.05) were observed. Nevertheless, the color alteration was within an acceptable threshold (∆E00 ≤ 1.8); Ra values: 3Y > 4Y > 5Y. SEM indicated a larger grain for 5Y > 4Y > 3Y. XRD indicated higher t-phase in 3Y, whereas higher c-phase in 5Y.

Conclusion

Increasing translucency and color alteration, and decreasing contrast and opalescence were influenced by Y content (5Y > 4Y > 3Y), region (I > M > C), and sintering rate (SS > FS > RS). Nonetheless, color alterations were within acceptable limits, suggesting the speed sintering rate to produce better color characteristics of restoration.

Keywords

color appearance - contrast - sintering rate - translucency - opalescence - zirconia


Publikationsverlauf

Artikel online veröffentlicht:
23. April 2025

© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

Thieme Medical and Scientific Publishers Pvt. Ltd.
A-12, 2nd Floor, Sector 2, Noida-201301 UP, India