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.

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.

Influence of CAD/CAM Grinding in the Performance of Sintered Dental Zirconia Framework

2012 ◽  
Vol 727-728 ◽  
pp. 1081-1084
Author(s):  
Carlos Nelson Elias ◽  
Andréa Mattos Melo ◽  
Claudinei dos Santos
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Surface Defects ◽  
Tetragonal Zirconia ◽  
Surface Cracks ◽  
Brittle Behavior ◽  
Dental Prostheses ◽  
Cad Cam ◽  
Ceramic Restorations ◽  
Tetragonal Zirconia Polycrystal

The brittle behavior of ceramics limits the use of these materials under conditions of cyclic loading, as is the case of fixed partial dentures. To improve toughness and biocompatibility of ceramics is necessary to employ powders with better purities, adjust the conditions of compaction and sintering, microstructure control and explore mechanisms for increasing the toughness. Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) is generally used for dental ceramic restorations. The zirconia framework is fabricated using the CAD/CAM system. The ceramic mechanical properties are determined by testing polished sample. Previous work did not analyze the influence of surface defects induced during dentures grinding. Ceramic restorations manufacturing are made with coarse grinding high-speed diamond rotatory cutting instruments. This process induces residual stresses and the high temperature induces surface cracks. Consequently, a lower strength and reliability of the material is observed. In this work the mechanical properties of yttria stabilized zirconia were determined with the use of samples of dental prostheses molded in patients and machined with the use of a dental laboratory CAD/CAM system. The results showed that the mechanical properties of pre-sintered blocks are different from prosthetics machined by CAD/CAM and sintered under the same conditions used in the laboratories of the prosthesis. The defects created during machining reduce the mechanical properties of zirconia.

scholarly journals Effect of Different Surface Treatments on Biaxial Flexural Strength of Yttria-stabilized Tetragonal Zirconia Polycrystal

2018 ◽  
Vol 19 (3) ◽  
pp. 318-323
Author(s):  
Teerthesh Jain ◽  
Amit Porwal ◽  
Sumanth Babu ◽  
Zahid A Khan ◽  
Chandeep Kaur ◽  
...  
Keyword(s):  
Low Temperature ◽  
Flexural Strength ◽  
Tetragonal Zirconia ◽  
Surface Treatments ◽  
Control Group ◽  
Significant Difference ◽  
Biaxial Flexural Strength ◽  
Computer Aided ◽  
The Impact ◽  
Tetragonal Zirconia Polycrystal

ABSTRACT Introduction Ceramics are widely applied in dentistry owing to their excellent mechanical and physical attributes. The most popular ceramics are Lava™, KaVo Everest, and Cercon. However, it is unclear whether or not a different surface treatment along with low-temperature aging and mechanical loading (ML) affects the physical properties of computer-aided design (CAD)/computer-aided manufacturing (CAM)-machined yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramic. Aim The objective of this research was to assess the impact of various surface treatments as air-particle abrasion, ML, low-temperature degradation (LTD), and their cumulative effects on biaxial flexural properties of Y-TZP. Materials and methods Totally, 50 specimens were fabricated by CAD–CAM machining from Cercon® and divided into five groups following different surface treatments as control (C), air-particle abrasion (Si), ML, LTD, and cumulative treatment (CT) group. Results were investigated by two-way analysis of variance (ANOVA) and Tukey honest significant difference (HSD) test. Results The highest biaxial flexural strength was observed in the Si group (950.2 ± 126.7 MPa), followed by the LTD group (861.3 ± 166.8 MPa), CT group (851.2 ± 126.5 MPa), and the least with ML (820 ± 110 MPa). A significant difference was observed in the two-way ANOVA test. X-ray diffraction (XRD) analysis showed that the control group consists of 100% tetragonal zirconia and the maximum amount of monoclinic phase was obtained after LTD. Conclusion No negative effect on biaxial flexural strength was observed; indeed, it increases the biaxial strength. Hence, these surface treatments can be done in routine clinical practice to improve the performance of ceramic restoration. How to cite this article Jain T, Porwal A, Babu S, Khan ZA, Kaur C, Jain RB. Effect of Different Surface Treatments on Biaxial Flexural Strength of Yttria-stabilized Tetragonal Zirconia Polycrystal. J Contemp Dent Pract 2018;19(3):318-323.

Evaluation of Mechanical Properties of Dental Feldsphatic Porcelains for Metal and Zirconia Core

2012 ◽  
Vol 727-728 ◽  
pp. 1104-1107
Author(s):  
Antonio Alves de Almeida-Junior ◽  
Gelson Luis Adabo ◽  
Beatriz Regalado Galvão ◽  
Diogo Longhini ◽  
Claudinei dos Santos
Keyword(s):  
Fracture Toughness ◽  
Flexural Strength ◽  
Vickers Hardness ◽  
High Hardness ◽  
Hardness Test ◽  
Dental Prostheses ◽  
Significant Incidence ◽  
Significant Difference ◽  
Fixed Dental Prostheses ◽  
Intermediate Value

Studies has been reported a significant incidence of chipping of the feldspathic porcelain veneer in zirconia-based restorations. The purpose of this study was to compare the three-point flexural strength (MPa), Weibull parameters, Vickers hardness (VHN) and Vickers indentation fracture toughness (MPa/mm1/2) in feldspatic porcelains for metal and for zirconia frameworks. Bar specimens were made with the porcelains e.MaxCeram (EM) and VitaVM9 (V9) for zirconia core, and Duceragold (DG) and VitaVMK95 (VK) for metal core (n= 15). Kruskal-Wallis and Dun test were used for statistical analysis. There was no significant difference (p=0.31) among the porcelains in the flexural strength (Median= 73.2; 74.6; 74.5; 74.4). Weibull calculation presented highest reliability for VK (10.8) followed by EM (7.1), V9 (5.7) and DG (5.6). Vickers hardness test showed that EM (536.3), V9 (579.9) and VK (522.1) had no difference and DG (489.6) had the lowest value (p.001). The highest fracture toughness was to VK (1.77), DG (1.58) had an intermediate value while V9 (1.33) and EM (1.18) had the lowest values (p.001). Despite of the suitable flexural strength, reliability and high hardness, the porcelains used to zirconia-based fixed dental prostheses showed lower fracture toughness values.

Flexural strength and reliability of CAD/CAM materials for dental applications

2018 ◽  
Vol 34 ◽  
pp. e9
Author(s):  
M.A. Basílio ◽  
E. Lima ◽  
A.B. Soares ◽  
P.F. Cesar
Keyword(s):  
Flexural Strength ◽  
Cad Cam ◽  
Dental Applications

scholarly journals Biaxial flexural strength and Weilbull characteristics of adhesively luted hybrid and reinforced CAD/CAM materials to dentin: effect of self-etching ceramic primer versus hydrofluoric acid etching

2020 ◽  
Vol 34 (12) ◽  
pp. 1253-1268
Author(s):  
João Paulo Mendes Tribst ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Gabriel Cirone Lopes ◽  
Alexandre Luiz Souto Borges ◽  
Marco Antonio Bottino ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Hydrofluoric Acid ◽  
Acid Etching ◽  
Biaxial Flexural Strength ◽  
Cad Cam

Surface quality of yttria-stabilized tetragonal zirconia polycrystal in CAD/CAM milling, sintering, polishing and sandblasting processes

2017 ◽  
Vol 65 ◽  
pp. 102-116 ◽  
Author(s):  
Abdur-Rasheed Alao ◽  
Richard Stoll ◽  
Xiao-Fei Song ◽  
Takashi Miyazaki ◽  
Yasuhiro Hotta ◽  
...  
Keyword(s):  
Surface Quality ◽  
Tetragonal Zirconia ◽  
Cad Cam ◽  
Tetragonal Zirconia Polycrystal

Effect of TiN Addition on Microstructure and Mechanical Properties of Zirconia Matrix Ceramic Tool Material

2004 ◽  
Vol 471-472 ◽  
pp. 321-325 ◽  
Author(s):  
Jing Sun ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Sui Lian Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Monoclinic Phase ◽  
Tetragonal Zirconia ◽  
Tool Material ◽  
Strengthening Mechanisms ◽  
Microstructure And Mechanical Properties ◽  
Ceramic Tool Material ◽  
Tetragonal Zirconia Polycrystal

In this paper, 3mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) and TiN/3Y-TZP(adding TiN particles to 3Y-TZP) composites were fabricated by hot-pressing technique. Phase composition, microstructure and mechanical properties of the composites were investigated. It is shown that the flexural strength, fracture toughness and Vickers hardness of TiN/3Y-TZP was significantly improved by the addition of TiN particles compared with 3Y-TZP. The flexural strength of ZYT2 (20wt% TiN addition) is 1318 MPa. The fracture toughness of ZYT4 (40wt% TiN addition) is 16.8MPa·m1/2. The toughening and strengthening mechanisms were analyzed. The XRD results show that the additing of TiN can hinder the transformation from tetragonal phase to monoclinic phase of 3Y-TZP during fabrication process.

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.

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