scholarly journals Additively Manufactured Zirconia for Dental Applications

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3694
Author(s):  
Hiroto Nakai ◽  
Masanao Inokoshi ◽  
Kosuke Nozaki ◽  
Keiji Komatsu ◽  
Shingo Kamijo ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Cross Sections ◽  
Oral Care ◽  
Tetragonal Zirconia ◽  
Crystallographic Analysis ◽  
Weibull Analysis ◽  
X Ray Diffraction ◽  
Biaxial Flexural Strength ◽  
Dental Applications ◽  
Similar Phase

We aimed to assess the crystallography, microstructure and flexural strength of zirconia-based ceramics made by stereolithography (SLA). Two additively manufactured 3 mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP: LithaCon 3Y 230, Lithoz; 3D Mix zirconia, 3DCeram Sinto) and one alumina-toughened zirconia (ATZ: 3D Mix ATZ, 3DCeram Sinto) were compared to subtractively manufactured 3Y-TZP (control: LAVA Plus, 3M Oral Care). Crystallographic analysis was conducted by X-ray diffraction. Top surfaces and cross-sections of the subsurface microstructure were characterized using scanning electron microscopy (SEM). Biaxial flexural strength was statistically compared using Weibull analysis. The additively and subtractively manufactured zirconia grades revealed a similar phase composition. The residual porosity of the SLA 3Y-TZPs and ATZ was comparable to that of subtractively manufactured 3Y-TZP. Weibull analysis revealed that the additively manufactured LithaCon 3Y 230 (Lithoz) had a significantly lower biaxial flexural strength than 3D Mix ATZ (3D Ceram Sinto). The biaxial flexural strength of the subtractively manufactured LAVA Plus (3M Oral Care) was in between those of the additively manufactured 3Y-TZPs, with the additively manufactured ATZ significantly outperforming the subtractively manufactured 3Y-TZP. Additively manufactured 3Y-TZP showed comparable crystallography, microstructure and flexural strength as the subtractively manufactured zirconia, thus potentially being a good option for dental implants.

Development of Y-TZP Pre-Sintered Blocks for CAD-CAM Machining of Dental Prostheses

2008 ◽  
Vol 591-593 ◽  
pp. 712-716 ◽  
Author(s):  
Roberta M.C. Sasahara ◽  
H.N. Yoshimura ◽  
Cátia Fredericci ◽  
Alberto Calasans ◽  
Paulo Francisco Cesar ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Vickers Hardness ◽  
Empirical Equation ◽  
Tetragonal Zirconia ◽  
Linear Shrinkage ◽  
Dental Prostheses ◽  
Biaxial Flexural Strength ◽  
Cad Cam ◽  
Dental Applications ◽  
Tetragonal Zirconia Polycrystal

The aim of this work was to establish a route to produce pre-sintered blocks of Y-TZP (yttria stabilized tetragonal zirconia polycrystal) suitable to be machined in a commercial CADCAM system, used to manufacture crowns and bridge frameworks for dental applications. Two commercial Y-TZP powders were investigated. The powders were pressed with different compaction pressures (40 to 500 MPa) and pre-sintered at temperature ranging from 900 to 1100°C. Vickers hardness, biaxial flexural strength, and linear shrinkage could be correlated to the relative density of pre-sintered samples. Using an empirical equation, pre-sintered blocks with a pre-defined density could be prepared. The blocks withstood the machining in a CAD-CAM system, and the machined and sintered crowns presented good adaptation.

Impact of Silane-containing Universal Adhesive on the Biaxial Flexural Strength of a Resin Cement/Glass-ceramic System

2019 ◽  
Vol 44 (2) ◽  
pp. 200-209 ◽  
Author(s):  
F Murillo-Gómez ◽  
RB Wanderley ◽  
MF De Goes
Keyword(s):  
Flexural Strength ◽  
Glass Ceramic ◽  
Resin Cement ◽  
Weibull Analysis ◽  
Ceramic System ◽  
Universal Adhesive ◽  
Bonded Interface ◽  
Biaxial Flexural Strength ◽  
Digital Caliper ◽  
One Way Anova

SUMMARY The aim of this study was to determine whether using a silane-containing universal adhesive as a silane primer in glass-ceramic/resin cement systems affects biaxial flexural strength (BFS) and bonded interface integrity after loading. Glass-ceramic (IPS e.max CAD, Ivoclar/Vivadent, Schaan, Liechtenstein) disc-shaped specimens (6.5±0.1mm in diameter, 0.5±0.1mm thick) were etched with 5% hydrofluoric acid (HF) for 20 seconds and divided into four groups of 30 specimens, to be treated as follows: 1) One bottle silane primer (RCP); 2) Separate application of silane and adhesive (RCP+SB); 3) Silane-containing universal adhesive (SBU); 4) No treatment (C). After silanization, all specimens were resin cement– coated and polymerized for 40 seconds. Each specimen layer was measured, as well as each assembly's thickness, using a digital caliper and scanning electron microscope (SEM). Specimens were stored for 24 hours and submitted to a BFS test (1.27 mm/min). BFS values were calculated using the bilayer disc-specimen solution. Bonded interfaces were analyzed on fractured fragments using SEM. One-way ANOVA and Tukey tests (α=0.05) were applied, as well as the Weibull analysis. Factor “silane treatment” was statistically significant (p<0.0001). RCP+SB (372.2±29.4 MPa) and RCP (364.2±29.5 MPa) produced significantly higher BFS than did the C (320.7±36.3 MPa) or SBU (338.0±27.1 MPa) groups. No differences were found in the Weibull modulus (m: RCP: 10.1-17.3; RCP+SB: 10.1-17.0; SBU: 12.3-22.4; C: 7.4-12.9). Bonded interface analysis exhibited ceramic-cement separation (SBU, C) and voids within the resin cement layer (all groups). Neither the ceramic/cement system's BFS nor its bonded interface stability were improved by SBU after loading.

Effect of Thermocycling on Biaxial Flexural Strength of CAD/CAM, Bulk Fill, and Conventional Resin Composite Materials

2019 ◽  
Vol 44 (5) ◽  
pp. E254-E262 ◽  
Author(s):  
EB Benalcázar Jalkh ◽  
CM Machado ◽  
M Gianinni ◽  
I Beltramini ◽  
MMT Piza ◽  
...  
Keyword(s):  
Composite Materials ◽  
Flexural Strength ◽  
Weibull Modulus ◽  
Resin Composite ◽  
Oral Care ◽  
Testing Machine ◽  
Biaxial Flexural Strength ◽  
Computer Aided ◽  
Cad Cam ◽  
Characteristic Stress

SUMMARY New resin-based restorative materials have been developed, such as computer-aided design/computer-aided manufacturing (CAD/CAM) and bulk-fill composites, as an alternative to traditional layering techniques. This study evaluated the biaxial flexural strength (BFS) before and after thermocycling of five different resin composites: one hybrid resin/ceramic CAD/CAM indirect material, Lava Ultimate CAD-CAM Restorative (LU, 3M Oral Care); a conventional composite, Filtek Z350 XT (Z350, 3M Oral Care); two bulk-fill composites, Tetric N-Ceram Bulk Fill (TBF, Ivoclar Vivadent) and Filtek Bulk Fill (FBF, 3M Oral Care); and one bulk-fill flow resin composite, Filtek Bulk Fill Flow (FBFF, 3M Oral Care). Three hundred disc-shaped specimens (6.5 mm in diameter and 0.5 mm thick) were fabricated and divided into five groups (n=30 for each composite and condition). The BFS test was performed in a universal testing machine at a crosshead speed of 0.5 mm/min immediately (i, 24 hours) and after thermocycling (a, 500 thermal cycles of 5°C to 55°C with a 30-second dwell time). The Weibull modulus (m) and characteristic stress (η) were calculated, and a contour plot was used (m vs η) to detect differences between groups (95% two-sided confidence intervals). Significantly higher characteristic stress was observed for LUi (286.6 MPa) and Z350i (248.8 MPa) compared to the bulk-fill groups (FBFi=187.9 MPa, FBFFi=175.9 MPa, TBFi=149.9 MPa), with no differences between LUi and Z350i. Thermocycling significantly decreased the characteristic stress of all groups with the highest values observed for LUa (186.7 MPa) and Z350a (188.9 MPa) and the lowest for FBFFa (90.3 MPa). Intermediate values were observed for FBFa (151.6 MPa) and TBFa (122.8 MPa). The Weibull modulus decreased only for FBFa compared to FBFi. Composition and thermocycling significantly influenced the biaxial flexural strength of resin composite materials.

Biaxial flexural strength of new Bis-GMA/TEGDMA based composites with different fillers for dental applications

2016 ◽  
Vol 32 (9) ◽  
pp. 1073-1078 ◽  
Author(s):  
Sebastian Wille ◽  
Iris Hölken ◽  
Galina Haidarschin ◽  
Rainer Adelung ◽  
Matthias Kern
Keyword(s):  
Flexural Strength ◽  
Biaxial Flexural Strength ◽  
Dental Applications

scholarly journals Effect of Low-Concentration Hydrofluoric Acid Etching on Shear Bond Strength and Biaxial Flexural Strength after Thermocycling

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1409
Author(s):  
You-Jung Kang ◽  
Yooseok Shin ◽  
Jee-Hwan Kim
Keyword(s):  
Phase Transformation ◽  
Flexural Strength ◽  
Bond Strength ◽  
Hydrofluoric Acid ◽  
Shear Bond Strength ◽  
Tetragonal Zirconia ◽  
Resin Cement ◽  
Air Abrasion ◽  
Biaxial Flexural Strength ◽  
Group A

This study evaluated the shear bond strength (SBS) and biaxial flexural strength (BFS) of resin cements according to the surface treatment method using low-temperature hot etching with hydrofluoric acid (HF) on a yttrium-stabilized tetragonal zirconia (Y-TZP) surface; 96 discs and 72 cubes for BFS and SBS tests for Y-TZP were randomly divided into four groups of BFS and three groups of SBS. Specimens were subjected to the following surface treatments: (1) no treatment (C), (2) air abrasion with 50 μm Al2O3 particles (A), (3) hot etching with HF at 100 °C for 10 min (E), and (4) air abrasion + hot etching (AE). After treatments, the specimens were coated with primer, and resin cement was applied with molds. The specimens were evaluated for roughness (Ra) via scanning electron microscopy and x-ray diffraction, and the data were analyzed by an analysis of variance (ANOVA) and Kruskal–Wallis tests. Group E produced significantly higher SBS compared to group A and AE before and after thermocycling. The BFSs of all groups showed no significant differences before thermocycling; however, after thermocycling, C and E treatment groups were significantly higher compared to group A and AE. All groups showed phase transformation. Group E was observed lower monoclinic phase transformation compared to other groups.

INFLUENCE OF PROCESSING ON MECHANICAL PROPERTIES OF 3Y-TZP FOR DENTAL APPLICATIONS

2016 ◽  
Vol 78 (11-3) ◽  
Author(s):  
Mohamed Aboras ◽  
Andanastuti Muchtar ◽  
Che Husna Azhari ◽  
Norziha Yahaya ◽  
Chin Chuin Hao
Keyword(s):  
Mechanical Properties ◽  
Phase Distribution ◽  
Slip Casting ◽  
Tetragonal Zirconia ◽  
Casting Process ◽  
Cold Isostatic Pressing ◽  
Colloidal Processing ◽  
X Ray Diffraction ◽  
Consolidation Process ◽  
Dental Applications

Purpose: This study aimed to investigate the influence of processing on the mechanical properties of 3 mol% yttrium–tetragonal zirconia (3Y–TZP) for dental applications. In this study, cold isostatic pressing (CIP) was adopted as a second consolidation process to enhance the mechanical properties of slip-cast 3Y–TZP. Methods: Two batches were prepared. The first batch of 3Y–TZP suspension was fabricated via colloidal processing. Then, the suspension was subjected to the slip casting process. Simultaneously, the second batch was prepared via colloidal processing, followed by CIP. The specimens were sintered at 1600 °C.  Sintered density, hardness, microstructure, and phase distribution were examined and analyzed. Results showed that the specimens fabricated via slip casting and CIP had the highest density of 99% of the theoretical density (6.1 g/cm3) and hardness of 14.4 GPa. The microstructure of the CIP samples was homogeneous with low porosity. According to X-ray diffraction examination, both batches exhibited a single phase (tetragonal phase). Conclusion(s): The density, hardness, and homogeneity of the microstructure of Y–TZP fabricated via slip casting and CIP improved. Using CIP as the second consolidation method improved the quality of green bodies

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