CLINICAL AND EXPERIMENTAL HEALTH SCIENCES, vol.14, no.1, pp.45-53, 2024 (ESCI)
ABSTRACT
Objective: This study aimed to investigate the effect of low-temperature degradation (LTD) in phase transformation and biaxial flexural
strength of high-translucent yttria partially stabilized zirconia (Y-PSZ) and yttria tetragonal zirconia polycrystalline (3-YTZP).
Methods: A total of 120 new high-translucent 3-YTZP (NMS) and Y – PSZ (KST, KUT, NQ3MS) zirconia disc specimens were manufactured
according to ISO 6872 for biaxial flexural strength (14 mm., 1.2 ± 0.02 mm). The specimens from each type of material were divided into
3 subgroups (n:30) according to the LTD in an autoclave at 134 C0 at 2 bar (n:10) (at 5, 20 hour (h)). Specimens without LTD served as
the control. Data of the monoclinic phase changes (Xm) and flexural strength were analyzed using two-way ANOVA followed by post hoc
MannWhitney U test. Weibull statistics were used to analyze strength reliability.
Results: LTD increased the monoclinic content significantly for NMS and slightly for the KST group. A monoclinic phase was not detected for
KUT and NQ3MS groups. The biaxial flexural strength of the NMS group was affected significantly and decreased with an increase in the 20
h aging. For flexural strength values, there was no significant difference in aging times for each of the KST, KUT, and NQ3MS groups. Weibull
analysis showed the highest characteristic strength for NMS (1412.9), KST (750.1), NQ3MS(790.5) and KUT (615.2) groups. The Weibull
modulus (m) increased in the NMS, KUT, and NQ3MS groups compared with the control group and decreased in the KST group.
Conclusion: LTD caused a significant decrease in the biaxial flexural strength results of the NMS group but did not significantly affect the KST,
KUT, and NQ3MS groups’ values.
Keywords: High-translucent zirconia, Low-temperature degradation, Phase transformation, Biaxial flexural strength