Optical Properties and Flexural Strength of Artificially Aged Tetragonal/Cubic Ultra-Translucent Zirconia

Abstract

Purpose: The present study aimed to evaluate the effect of artificial aging on the optical properties and flexural strength of ultra-translucent tetragonal/cubic zirconia. Materials and Methods: A total of 30 (N=30) ultra-translucent cubic zirconia discs (DD cube X 2) were fabricated. Samples were divided into 3 equal groups (n=10) according to the aging protocol followed including Group (1): (control), samples were not subjected to hydrothermal aging protocol, (n=10), Group (2): Samples were subjected to one-hour hydrothermal aging protocol, (n=10), Group (3): Samples were subjected to 3 hours hydrothermal aging protocol, (n=10). Samples of each group were subjected to optical properties determination using spectrophotometer including (Translucency parameter TP, Contrast ratio CR, Change in color ΔE) and biaxial flexural strength determination using universal testing machine. Obtained values were statistically analyzed. Results: Statistical analysis using ANOVA test revealed no significant difference between the three tested groups. The highest mean value of translucency and biaxial flexural strength were recorded at the control group. While group (3) samples recorded the lowest mean values. Color change (ΔE) was performed for groups (2 and 3) to detect the amount of color change from control group. Group (3) samples recorded higher mean values than group (2) samples. Conclusions: Hydrothermal aging did not affect the optical properties and flexural strength of tetragonal / cubic zirconia (DD cube X 2).

The color stability of multilayered super translucent monolithic zirconia (stm-Zr) cemented to different implant-abutment substrates after accelerated ageing in vitro.

“…The results of this study are in agreement with Kim, H.-K., & Kim, S.-H. (49), who concluded that hydrothermal ageing affected pre-colored monolithic zirconia ceramics' optical properties and microstructure. The findings of this work contradict those of Ahmed et al (50), who investigated the optical properties of ultra-translucent tetragonal/cubic zirconia after artificial ageing. The optical characteristics and flexural strength of tetragonal/cubic zirconia are not affected by hydrothermal aging, they claim.…”

Optical Properties of Newly Developed Monolithic CAD/CAM Materials After Aging

“…However, unlike the studies of Sen and Us, LS 2 baseline TP values were significantly higher than ZLS baseline TP values. The literature contains a wide range of results from studies on the effect of aging on translucency (33,41,42,43).…”

Effect of Aging on Translucency and Flexural Strength of Different Zirconia Materials (An In-Vitro Study)

“…The aging periods were (5, 10, 20, 30, 80, 100 hours). [11,12,13,14,15,16] Camposilvan E, et al (2018) stated that one hour of accelerated aging at 134°C is approximately equal to 2 -4 years at 37 °C in the oral cavity. [4] In our study aging was done for 10 hours at 134C° and a pressure of 2 bar.…”