The Effect of Hydrothermal Aging on The Color Stability of Gradient Zirconia. In Vitro Study

Ramadan, Mennat Allah Khaled; Zaghloul, Hanaa Hassan; Hamza, Tamer A

doi:10.21608/asdj.2024.264791.1203

The Effect of Hydrothermal Aging on The Color Stability of Gradient Zirconia. In Vitro Study

Document Type : Original articles

Authors

¹ Resident dentist at BUC, Cairo- Egypt.

² • Professor of Fixed Prosthodontics, Faculty of Oral and Dental medicine, Misr International University, Cairo-Egypt • Faculty of Dentistry-Noura Bint Abdel Rahman University, Riyadh-Saudi Arabia

³ Dean Badr university in Cairo BUC, Professor of Fixed Prosthodontics Faculty of Oral and Dental medicine, Badr University, Cairo- Egypt.

10.21608/asdj.2024.264791.1203

Abstract

Aim: The study aims to assess the influence of hydrothermal aging on gradient zirconia's microstructure and color stability. Materials and methods: Ten discs were constructed from gradient zirconia blanks (3Y-TZP-5Y-TZP) using CAD\CAM technology. Hydrothermal aging was done in an autoclave. Color parameters (a*, b*, L*) for each disc was measured using a spectrophotometer. In order to investigate the zirconia specimens' crystalline structure, X-ray diffraction (XRD) was performed. Color stability and microstructural changes were examined before and after the aging process. Results: Following hydrothermal aging, a statistically significant decrease in the mean (L*) value was found. However, following hydrothermal aging, a statistically significant increase in the mean (a*) and (b*) values was reported. Regarding the microstructure, hydrothermal aging did not result in any significant changes. Conclusion: Artificial aging has led to color changes in gradient zirconia that were in the clinical acceptability range, but has no impact on the microstructure of gradient zirconia.

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