Effect of Different Flaw Sizes and Surface Treatment on Biaxial Flexural Strength of Feldspathic Porcelain

Feldspathic porcelain paste system using organic vehicle was prepared and applied to fabricate the porcelain fused to metal fixed partial denture. The mean linear fired shrinkage of paste porcelain system was 15.2% that is 0.8% lower than that of conventional build-up method. The color difference between two methods (􀁕E*) was 0.156. Mean biaxial flexural strength of sintered preformed laminating porcelains of this system and conventionally build-up porcelains were 74±3 and 70±4 MPa respectively. There was no deterioration of physical properties of feldspathic porcelain system by introducing organic vehicle, and this new build-up method can be applied to fabricate the porcelain fused to metal restorations.

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Effect of Sandblasting Angle and Distance on Biaxial Flexural Strength of Zirconia-based Ceramics

The Journal of Contemporary Dental Practice ◽

10.5005/jp-journals-10024-2062 ◽

2017 ◽

Vol 18 (6) ◽

pp. 443-447 ◽

Cited By ~ 4

Author(s):

Safoura Ghodsi ◽

Somayeh Zeighami ◽

Ali Gheidari ◽

Hoseinali Mahgoli ◽

Ahmad Rohanian

Keyword(s):

Surface Roughness ◽

Flexural Strength ◽

Surface Treatment ◽

Study Groups ◽

Treatment Method ◽

Luting Cements ◽

Significant Difference ◽

Biaxial Flexural Strength ◽

Nozzle Head

ABSTRACT Aim Surface treatment is necessarily required for bonding of zirconia to the veneering porcelain and luting cements. Sandblasting is the most common and probably the most efficient surface treatment method. Sandblasting roughens the surface and may affect the flexural strength of zirconia. Different sandblasting protocols may yield variable results. This study sought to assess the effect of sandblasting angle and distance on the biaxial flexural strength of zirconia-based ceramics. Materials and methods This in vitro experimental study was conducted on 50 zirconia discs measuring 1.2 ± 0.2 mm in thickness and 15 ± 0.2 mm in diameter, which were randomly divided into five groups (n = 10) of one control and four experimental groups subjected to sandblasting with 110 µm aluminum oxide particles under 2 bar pressure for 10 seconds at 15 and 25 mm distances and 45 and 90° angles (between the nozzle head and zirconia surface). Surface roughness was measured by a roughness tester and samples were subjected to thermocycling followed by biaxial flexural strength testing according to ISO6872. The data were analyzed using one-way analysis of variance (p < 0.05). Results No statistically significant difference was noted in the mean biaxial flexural strength of the five groups (p = 0.40). Different sandblasting protocols yielded significantly different surface roughness values (p < 0.001). The highest and the lowest mean surface roughness belonged to 15 mm/90° (0.51 µm) and control (0.001 µm) groups respectively. Conclusion Change in sandblasting angle and distance had no significant effect on the biaxial flexural strength of zirconiabased ceramic, but surface roughness was significantly different in the study groups. Clinical significances Regardless of sandblasting angle, increasing distance to 25 mm significantly decreases surface roughness that may negatively affect zirconia bond strength. How to cite this article Zeighami S, Gheidari A, Mahgoli H, Rohanian A, Ghodsi S. Effect of Sandblasting Angle and Distance on Biaxial Flexural Strength of Zirconia-based Ceramics. J Contemp Dent Pract 2017;18(6):443-447.

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Influence of Aging on Biaxial Flexural Strength and Hardness of Translucent 3Y-TZP

Materials ◽

10.3390/ma13010027 ◽

2019 ◽

Vol 13 (1) ◽

pp. 27 ◽

Cited By ~ 1

Author(s):

Nawal M. Moqbel ◽

Majed Al-Akhali ◽

Sebastian Wille ◽

Matthias Kern

Keyword(s):

Flexural Strength ◽

Surface Treatment ◽

Laser Scanning ◽

Monoclinic Phase ◽

X Ray Diffraction ◽

Air Abrasion ◽

Aged Group ◽

Alumina Particles ◽

Biaxial Flexural Strength ◽

Group A

The purpose of this research was to evaluate the influence of aging and surface treatment on surface roughness, biaxial flexural strength (BFS), and Vickers hardness (VHN) of translucent dental zirconia. Half of 80 disc-shaped zirconia specimens (1.2 mm thickness and 12 mm diameter) were aged (group A) in an autoclave for 20 h (134 °C and 0.2 MPa) and the other half were not aged (group N). Specimens were subjected to: no surface treatment (SIN), particle air-abrasion with 50 µm alumina particles at 1 bar (0.1 MPa) and 2.5 bar (0.25 MPa), or polishing down to 1 µm (POL). Specimens were analyzed using X-ray diffraction, laser scanning microscope, BFS, and VHN tests. Three groups (N-SIN, N-POL, and A-POL) showed almost no monoclinic phase. While other groups showed monoclinic phase ratios ranging from 7.5 vol. % ± 2.4 vol. % (N-0.1 MPa) to 41.5 vol. % ± 0.3 vol. % (A-0.1 MPa). Aging and particle air-abrasion increased significantly the BFS, ranging from 720 ± 37 MPa (N-SIN) to 1153 ± 92 MPa (N-0.1 MPa). The hardness was not influenced significantly by aging. A certain amount of monoclinic phase at the surface strengthens the high translucent dental zirconia, while hardness and roughness are not influenced. The pressure of particle air-abrasion showed no influence on the evaluated properties.

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Effects of Pretreatment, Specimen Thickness, and Artificial Aging on Biaxial Flexural Strength of Two Types of Y-TZP Ceramics

Operative Dentistry ◽

10.2341/18-071-l ◽

2019 ◽

Vol 44 (6) ◽

pp. 615-624

Author(s):

A Sundh ◽

W Kou ◽

G Sjögren

Keyword(s):

Flexural Strength ◽

Surface Treatment ◽

Pearson Correlation ◽

Tetragonal Zirconia ◽

Specimen Thickness ◽

Test Analysis ◽

Heat Treated ◽

Biaxial Flexural Strength ◽

Correlation Tests ◽

Post Hoc

SUMMARYObjectives:To evaluate the effects of surface treatment, specimen thickness, and aging on the biaxial flexural strength (BFS) of two types of yttria-stabilized, tetragonal zirconia polycrystal (Y-TZP) ceramics.Methods and Materials:Disc-shaped specimens, 0.4 and 1.3 mm thick, made from hot isostatic pressed (Denzir) and non–hot isostatic pressed (ZirPlus) Y-TZP, were sandblasted, heat treated, and autoclaved. The surface topography was assessed in accordance with European Standard 623-624:2004 and the BFS tests in accordance with International Organization for Standardization Standard 6872:2008. For statistical analyses, one-way Shapiro-Wilk test, analysis of variance (post hoc: least significant differences), Mann-Whitney U-test, and Pearson correlation tests (p<0.05) were used.Results:As delivered, the BFS of the 0.4-mm ZirPlus was >1.3-mm ZirPlus (p<0.01), and the BFS of the 0.4-mm Denzir was >1.3-mm Denzir (p<0.001). Sandblasting with 0.2 MPa reduced the BFS of the ZirPlus and Denzir discs (p<0.01), whereas sandblasting with 0.6 MPa increased the BFS of the 0.4-mm Denzir (p<0.001) and reduced the BFS of the 0.4-mm ZirPlus (p<0.05). Heat treatment significantly reduced the BFS of all the groups except for the 0.6 MPa sandblasted 0.4-mm ZirPlus. Autoclaving reduced the BFS of the as-delivered ZirPlus and Denzir specimens (p<0.001), whereas autoclaving the 0.6 MPa sandblasted and heat-treated specimens had no effect (p>0.05) on the BFS. The 0.6 MPa sandblasted, heat-treated, and autoclaved 0.4-mm Denzir exhibited higher BFS than the 0.6 MPa sandblasted, heat-treated, and autoclaved 0.4-mm ZirPlus (p<0.05).Conclusions:Thickness and surface treatment of Y-TZP–based ceramics should be considered since those factors could influence the BFS of the material.

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