Title: 2949 - Effect of Thermocycle Aging on Color Stability of Monolithic Zirconia


Merve Köseoglu, Ataturk University Faculty of Dentistry
Berkman Albayrak (Presenter)
Ataturk University Faculty of Dentistry

Pιnar Gül, Ataturk University Faculty of Dentistry
Funda Bayindir, Ataturk University


Objectives: To evaluate the effect of thermocycle aging on the color stability of monolithic zirconia.

Methods: A total of 80 disc-shaped specimens (1 cm diameter) were produced from monolithic zirconia material, Katana High Translucent. The specimens were prepared in four different thicknesses: 0.5 mm (G1), 1 mm (G2), 1.5 mm (G3) and 2 mm (G4). All the specimens were subjected thermocycle stressing (5°C and 55°C, 60 s dwell time) for 5000 cycles. The initial and final CIE L*a*b* coordinates were measured with a spectrophotometer and color differences (ΔE) were calculated. Data obtained from the study were evaluated by descriptive statistics, correlation analysis, Kolmogorov-Smirnov test, one-way ANOVA and Tukey test.

Results: After thermocycle aging, L*a*b* values decreased for all groups. G4 showed the highest color stability (ΔE=0,85±0,01) and the maximum color difference was observed in G1 (ΔE=0,91±0,02). There was no statistically significant difference in color (ΔE) and L*a*b* values (p〉0,05). Significant color difference was only observed in the thinnest specimens, G1 (p〈0,05).

Conclusions: After thermocyle aging, discrete color differences were observed only in G1. Other groups showed no significant L*a*b* differences. With in the limitations of this in vitro study, the color stability of monolithic zirconia increases in the thickness over 0.5 mm.

Student Presenter

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE