[PPS-P-5] Evaluation of extra-high translucent zirconia: translucency, crystalline phase, mechanical properties
[Abstract]
[Objective]The objective of this study was to investigate the translucency, crystalline phase, and mechanical properties of yttria-partially stabilized zirconia (Y-PSZ).
[Method]Three fully-sintered Y-PSZ zirconia specimens (Zpex 4.m, 4Y-PSZ, Tosoh; Zpex Smile.m, 5Y-PSZ, Tosoh; Disk ZR lucent ultra, 6Y-PSZ, Shofu) were prepared. Dimensions of these zirconia specimens after sintering were 14.5 mm (diameter) and 1.2 mm (thickness). Translucency was assessed using a colorimeter (n=7). Data were statistically compared using the Shapiro-Wilk test followed by either one-way ANOVA with Tukey post-hoc test or the Kruskal-Wallis test with Dunn’s test. Crystalline phase analysis was performed using X-ray diffraction (XRD), followed by the Rietveld refinement (n=3). Mechanical properties were assessed using a biaxial flexural strength test (n=20), followed by Weibull analysis.
[Results and Discussion]One-way ANOVA followed by the Tukey post-hoc test was used based on the results of the Shapiro-Wilk test. The translucency parameter (TP) values of Disk ZR lucent ultra were higher than the TP values of Zpex Smile.m. The TP values of Zpex Smile.m were higher than the TP values of Zpex 4.m.Recently, high translucent zirconia was reported to have two peaks of tetragonal zirconia. First peak of tetragonal zirconia was written as t-ZrO2, second peak of tetragonal zirconia as t’-ZrO2, cubic zirconia as c-ZrO2, and monoclinic zirconia as m-ZrO2. Regarding zirconia-phase composition, XRD with Rietveld analysis revealed that t-ZrO2 was the highest (45.6 wt%) for Zpex 4.m, followed by t’-ZrO2 (37.7 wt%) phase. On the other hand, in Zpex Smile.m and Disk ZR lucent ultra, t’-ZrO2 (61.1-70.7 wt%) was the highest.Weibull analysis revealed that the Weibull modulus of Zpex 4.m, Zpex Smile.m, and Disk ZR lucent ultra were 5.8, 4.1, and 6.5, respectively, whereas the characteristic biaxial flexural strength of Zpex 4.m, Zpex Smile.m and Disk ZR lucent ultra were 1555 MPa, 979 MPa, and 623 MPa, respectively.Our previous study reported that a higher amount of yttria zirconia composed, higher translucency, and lower mechanical properties zirconia had. Our results corresponded with their report.
[Objective]The objective of this study was to investigate the translucency, crystalline phase, and mechanical properties of yttria-partially stabilized zirconia (Y-PSZ).
[Method]Three fully-sintered Y-PSZ zirconia specimens (Zpex 4.m, 4Y-PSZ, Tosoh; Zpex Smile.m, 5Y-PSZ, Tosoh; Disk ZR lucent ultra, 6Y-PSZ, Shofu) were prepared. Dimensions of these zirconia specimens after sintering were 14.5 mm (diameter) and 1.2 mm (thickness). Translucency was assessed using a colorimeter (n=7). Data were statistically compared using the Shapiro-Wilk test followed by either one-way ANOVA with Tukey post-hoc test or the Kruskal-Wallis test with Dunn’s test. Crystalline phase analysis was performed using X-ray diffraction (XRD), followed by the Rietveld refinement (n=3). Mechanical properties were assessed using a biaxial flexural strength test (n=20), followed by Weibull analysis.
[Results and Discussion]One-way ANOVA followed by the Tukey post-hoc test was used based on the results of the Shapiro-Wilk test. The translucency parameter (TP) values of Disk ZR lucent ultra were higher than the TP values of Zpex Smile.m. The TP values of Zpex Smile.m were higher than the TP values of Zpex 4.m.Recently, high translucent zirconia was reported to have two peaks of tetragonal zirconia. First peak of tetragonal zirconia was written as t-ZrO2, second peak of tetragonal zirconia as t’-ZrO2, cubic zirconia as c-ZrO2, and monoclinic zirconia as m-ZrO2. Regarding zirconia-phase composition, XRD with Rietveld analysis revealed that t-ZrO2 was the highest (45.6 wt%) for Zpex 4.m, followed by t’-ZrO2 (37.7 wt%) phase. On the other hand, in Zpex Smile.m and Disk ZR lucent ultra, t’-ZrO2 (61.1-70.7 wt%) was the highest.Weibull analysis revealed that the Weibull modulus of Zpex 4.m, Zpex Smile.m, and Disk ZR lucent ultra were 5.8, 4.1, and 6.5, respectively, whereas the characteristic biaxial flexural strength of Zpex 4.m, Zpex Smile.m and Disk ZR lucent ultra were 1555 MPa, 979 MPa, and 623 MPa, respectively.Our previous study reported that a higher amount of yttria zirconia composed, higher translucency, and lower mechanical properties zirconia had. Our results corresponded with their report.