scholarly journals The effects of mechanical and hydrothermal aging on microstructure and biaxial flexural strength of an anterior and a posterior monolithic zirconia

2017 ◽  
Vol 63 ◽  
pp. 94-102 ◽  
Author(s):  
Eduardo Mariscal Muñoz ◽  
Diogo Longhini ◽  
Selma Gutierres Antonio ◽  
Gelson Luis Adabo
Keyword(s):  
Flexural Strength ◽  
Hydrothermal Aging ◽  
Biaxial Flexural Strength ◽  
Monolithic Zirconia

scholarly journals Biaxial flexural strength of different types of monolithic zirconia

2019 ◽  
Vol 22 (1) ◽  
pp. Process
Author(s):  
Shereen Ahmed Nossair ◽  
Tarek Salah ◽  
Kamal Khaled Ebeid
Keyword(s):  
Flexural Strength ◽  
Zirconia Ceramic ◽  
Group 4 ◽  
Dental Esthetics ◽  
Biaxial Flexural Strength ◽  
Different Types ◽  
Monolithic Zirconia ◽  
Group 5 ◽  
Group 2 ◽  
Post Hoc

Objective: This study was designed to evaluate the biaxial flexural strength (BFS) of different types of unshaded and shaded monolithic zirconia. Material and Methods: 120 monolithic zirconia ceramic discs were fabricated. They were divided into twelve groups (n=10), Group 1; Bruxzir unshaded, Group 2; Bruxzir shaded A2, Group 3; Bruxzir anterior white, Group 4; Bruxzir anterior shade A2, Group 5; Prettau unshaded, Group 6; Prettau shaded with A2 coloring liquid, Group 7; Prettau anterior white, Group 8; Prettau anterior shaded with A2 coloring liquid, Group 9; Katana HT white, Group 10; Katana HT shade A2, Group 11; Katana ST white, Group 12; Katana ST shade A2. All discs were milled using a dental milling machine, and had final dimensions after sintering of 15 mm diameter and 1 mm thickness. BFS was tested using piston on three ball technique. Results:  One-way ANOVA revealed significant differences among the 12 groups. Tukey post-hoc tests revealed no significant differences between the groups 3, 4, ,7 ,8 11, and 12. However, they all had BFS values that are significantly lower than all other groups. Group 2 showed statistically significant higher BFS values when compared to group 3,4, 7, 8, 11, and 12 while it showed statistically significant lower values when compared to groups 1, 5, 6, 9, and 10. Conclusion: Increase in the yttria content in zirconia led to a decrease in its BFS. Shading of zirconia did not have a significant effect on the final strength of zirconia. KeywordsDental ceramics; Dental esthetics; Flexural strength; Shaded zirconia. 

scholarly journals A comparative study of biaxial flexural strength and Vickers microhardness of different zirconia materials: Effect of glazing and thermal cycling

2015 ◽  
Vol 18 (2) ◽  
pp. 19 ◽  
Author(s):  
Esra Salihoglu Yener ◽  
Mutlu Ozcan ◽  
Ender Kazazoglu
Keyword(s):  
Flexural Strength ◽  
Thermal Cycling ◽  
Vickers Hardness ◽  
Vickers Microhardness ◽  
Testing Machine ◽  
Clinical Importance ◽  
Zirconia Ceramics ◽  
Biaxial Flexural Strength ◽  
Monolithic Zirconia ◽  
One Way Anova

<p class="western" lang="en-GB" align="left"><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Objective:</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">This study evaluated the effect of glazing and thermal cycling on biaxial flexural strength and Vickers hardness of different zirconia core materials. </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Material and </strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Methods: </strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">Disc shaped zirconia specimens (15 mm x </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">1.15 mm</span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">) were fabricated out of three systems (ZirkonZahn, Cercon, </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">Ceramill</span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">) according to each manufacturer`s instructions. The specimens of each system were randomly divided into initially 2 groups. While half of the specimens were glazed, the other half was left unglazed. Each group was further divided into 4 subgroups to be subjected to thermal cycling (0-control, 1000, 3000, 5000 cycles, 5-55 ºC). Biaxial flexural strength was tested in a universal testing machine (1 mm/min). Another set of unglazed zirconia specimens were made and tested for Vickers microhardness with and without thermocycling (0-control, 1000, 3000, 5000 cycles, 5-55 ºC). Data were statistically analyzed using one-way ANOVA, two-way ANOVA and Tukey’s test (</span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">p &lt;</span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"> 0.05). </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Results:</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"> In non-aged conditions (11034-1388 MPa), glazing significantly decreased the biaxial flexural strength of all zirconia ceramics (845.65-897.35 MPa) (p = 0.000). While in the non-glazed groups, all thermal cycling regimens significantly decreased the biaxial flexural strength (864-1156 MPa) (p=0.000), in glazed groups thermal cycling did not affect the results (829.4-854.9 MPa) (p = 0.405). Compared to the non-aged group (1414.1 VHN), thermal cycling decreased the Vickers hardness significantly only for Cercon (1365.9 VHN) (p = 0.005). </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Conclusion:</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"> Glazing decreased the biaxial flexural strength of the zirconia ceramics tested. Unglazed zirconia ceramics were weaker against thermal cycling compared to glazed ones. For monolithic zirconia restorations, this information may have clinical importance.</span></span></p><p class="western" align="justify"><span style="font-family: 'Times New Roman', serif;"><span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>K</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>eywords:</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">Biaxial flexural strength; Glazing; Thermal cycling; Vickers microhardness; Zirconia.</span></span></span></span></p>

scholarly journals Effects of Different Air Particle Abrasion Protocols on the Biaxial Flexural Strength and Fractography of High/Ultra-Translucent Zirconia

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 244
Author(s):  
Reem AlMutairi ◽  
Hend AlNahedh ◽  
Ahmed Maawadh ◽  
Ahmed Elhejazi
Keyword(s):  
Standard Deviation ◽  
Flexural Strength ◽  
Control Sample ◽  
Zirconia Ceramic ◽  
Air Abrasion ◽  
Zirconia Ceramics ◽  
Biaxial Flexural Strength ◽  
Monolithic Zirconia ◽  
The Mean ◽  
Post Hoc

In this study, the biaxial flexural strength (BFS) and fractography of high/ultra-translucent monolithic zirconia ceramics subjected to different mechanical surface pretreatments were evaluated. A total of 108 disc-shaped samples (12 mm diameter, 1.2 mm thickness) of three zirconia materials (5Y-ZP KATANA Zirconia UTML (ML), 3Y-TZP DD Bio ZX2 (DB), and 5Y-ZP DD cube X2 (DC)) were used. The BFS was investigated after subjecting the samples to surface treatment using air abrasion particles of two types (aluminum oxide or glass microbeads). The data were analyzed using two-way analysis of variance, followed by Scheffe’s post hoc test for multiple comparisons. The mean ± standard deviation BFS for DB was highest after treatment with 50 µm Al2O3 (1626.05 ± 31.9 MPa), with lower values being observed following treatment with 50 µm glass microbeads (1399.53 ± 24.2 MPa) and in the control sample (1198.51 ± 21.1 MPa). The mean ± standard deviation (SD) BFSs for DC and ML were the highest in the control groups. Surface air abrasion with 50 µm Al2O3 particles and 2 bar pressure is recommended for 3Y-TZP translucent zirconia, while no abrasion of 5Y-ZP translucent zirconia ceramic.

scholarly journals Effect of Different Coloring Procedures on the Aging Behavior of Dental Monolithic Zirconia

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Check Agingu ◽  
Neng-wu Jiang ◽  
Hui Cheng ◽  
Hao Yu
Keyword(s):  
Phase Transformation ◽  
Flexural Strength ◽  
Monoclinic Phase ◽  
Irregular Surface ◽  
Aging Behavior ◽  
Hydrothermal Aging ◽  
Transformation Zone ◽  
Aging Conditions ◽  
Monolithic Zirconia ◽  
Subsurface Microstructure

Objective. This study aimed to investigate the effect of different coloring procedures on the aging behavior of dental monolithic zirconia. Methods. Two types of translucent zirconia (SuperfectZir HTS, Aidite; Katana HT, Kuraray) were tested. Bar-shaped specimens with dimensions of 22 × 4 × 2 mm were prepared from uncolored and precolored blocks. Before being sintered, specimens made from uncolored blocks were colored by dipping them into a coloring liquid, whereas the precolored specimens were not treated. The specimens were then divided into 4 subgroups (n = 13) according to the aging conditions (no aging, 134°C/0.2 MPa for 5 h, 134°C/0.2 MPa for 10 h, and 134°C/0.2 MPa for 20 h). The flexural strength of the specimens was tested with the 4-point flexure. The crystalline phase composition of the specimens was analyzed by XRD. The subsurface microstructure of the fractured specimens was examined by using a SEM. The data were statistically analyzed using 3-way ANOVA and Tukey’s test (α = 0.05). Results. Significant differences were found in the flexural strength between the two zirconia materials tested (P<0.001). Aging and coloring procedures showed no significant effect on the flexural strength of the zirconia. Aging and coloring procedures significantly affected the t→m transformation of the zirconia. The monoclinic phase increased with the aging time. After aging, the precolored specimens showed a significantly higher t→m transformation than the specimens that were dipped in the coloring liquids. After aging for 20 h, the depth of the transformed zone with an irregular surface was approximately 6 µm for SuperfectZir HTS, whereas no detectable transformation zone was observed for Katana HT. Conclusion. Aging and coloring procedures had no significant effects on the flexural strength of the zirconia tested. The coloring procedure had a significant effect on the phase transformation of the zirconia subjected to hydrothermal aging.

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