Study of Machinable Dental Glass Ceramics

2009 ◽  
Vol 620-622 ◽  
pp. 575-578 ◽  
Author(s):  
Xin Pei Ma ◽  
Guang Xin Li ◽  
Zhi Hao Jin ◽  
Ji Hua Chen ◽  
Mao Ju Yang ◽  
...  
Keyword(s):  
Glass Ceramics ◽  
Orthogonal Experimental Design ◽  
Computer Assisted ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dental Restorations ◽  
Computer Assisted Design ◽  
All Ceramic ◽  
Cad Cam ◽  
Good Biocompatibility

Glass-ceramics are especially useful for the dental restorations because of their good biocompatibility, chemical stability, aesthetic, mechanical strength and wear resistance. The aim of this work was to obtain one mica glass-ceramic, which can be easily used for rapid machining into all-ceramic tooth with computer assisted design/computer assisted manufacture (CAD/CAM) devices. In the study, on the base of low melting machinable fluorosilicic mica glass ceramics, the effects of CeO2 and Fe2O3 in SiO2-B2O3-K2O-Na2O-Li2O-Al2O3-MgO-F system on color were studied. By orthogonal experimental design, the effects of crystallized parameters on the color, three point flexural strength and machinability of the glass ceramics were obtained, and the samples were analyzed by differential thermal analysis(DTA), X-ray diffraction (XRD) and scanning electron microscopy(SEM), respectively. Experimental results showed that the glass-ceramics with color close to the tooth can be obtained by adjusting the percentage of CeO2 and Fe2O3, and the glass-ceramics crystallized at 680°C for 2h have excellent mechanical properties and machinability.

Zirconia Blocks Properties Used for CAD/CAM Dentistry Restorations

2012 ◽  
Vol 727-728 ◽  
pp. 804-808 ◽  
Author(s):  
C. Santos ◽  
Carlos Nelson Elias ◽  
Andréa Matos Melo ◽  
Sérgio Neves Monteiro
Keyword(s):  
Mechanical Properties ◽  
Fracture Resistance ◽  
X Ray Diffraction ◽  
X Ray ◽  
M 10 ◽  
All Ceramic ◽  
Cad Cam ◽  
Ceramic Blocks ◽  
Bending Fracture ◽  
Cam Systems

Several CAD/CAM systems are available to dental prosthesis laboratories that can be used to make all-ceramic copings and frameworks. In Brazil, the use of these systems presents low demand, due principally the high blocks ceramics cost used for theses systems. The ceramic blocks are imported. To increase the dental ceramic CAD/CAM applications is necessary develop and produce the ceramics blocks in Brazil. The purpose of the present work is to compare the mechanical properties of blocks of zirconium developed in the Brazil (ProtMat® Co) and imported (VITA). It was determined the mechanical and physics properties of the two types of blocks of zirconium stabilized with ytria. The blocks have been sinterized at 1530 °C and their mechanical and physics properties were measured. The x-ray diffraction analysis showed only tetragonal phase, which improve the blocks toughness. The Vickers hardness and fracture toughness were 1300HV and 9 MPam1/2, respectively. High bending fracture resistance was obtained for both materials with average values of 910MPa. The Weibull modulus was m=10 for Brazilian and imported blocks. It was not observed an important difference among the microstructures and mechanical properties of the analyzed zirconium blocks.

scholarly journals Hydrothermal Ageing and Its Effect on Fracture Load of Zirconia Dental Implants

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3103
Author(s):  
Laurent Gremillard ◽  
Agnès Mattlet ◽  
Alexandre Mathevon ◽  
Damien Fabrègue ◽  
Bruno Zberg ◽  
...  
Keyword(s):  
Dental Implants ◽  
Fracture Load ◽  
Accelerated Ageing ◽  
Dental Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dental Restorations ◽  
Different Temperatures ◽  
Mechanical Performances ◽  
Kinetics Of

Due to growing demand for metal-free dental restorations, dental ceramics, especially dental zirconia, represent an increasing share of the dental implants market. They may offer mechanical performances of the same range as titanium ones. However, their use is still restricted by a lack of confidence in their durability and, in particular, in their ability to resist hydrothermal ageing. In the present study, the ageing kinetics of commercial zirconia dental implants are characterized by X-ray diffraction after accelerated ageing in an autoclave at different temperatures, enabling their extrapolation to body temperature. Measurements of the fracture loads show no effect of hydrothermal ageing even after ageing treatments simulated a 90-year implantation.

Effect of Particle Size of ZrO2(Y2O3) Powders on the Shrinkage of the Sintered Substrate with Coloring Gradient

2014 ◽  
Vol 87 ◽  
pp. 162-168
Author(s):  
Paula Cipriano da Silva ◽  
Roberto de Oliveira Magnago ◽  
Camila Aparecida Araujo da Silva ◽  
Bianca de Almeida Fortes ◽  
Claudinei dos Santos
Keyword(s):  
White Layer ◽  
Linear Shrinkage ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Particles Size Distribution ◽  
Cad Cam ◽  
Effect Of Particle Size ◽  
Cam Systems ◽  
Zirconia Powders

ZrO2(Y2O3)-based ceramics with coloring gradient can facilitate the development of dental prosthesis by the improvement of esthetic properties. In this work, ZrO2 powders with different particle sizes were investigated. White and yellow zirconia powders (TOSOH Corporation-Japan) were characterized by particles size distribution using nanoSight-LM20 analyzer. Furthermore, samples were characterized by X-Ray diffraction, Scanning Electron Microscopy and relative density. Compacts with two layers, one white and one yellow were uniaxially pressed at 80MPa and sintered at 1530°C-120min. The yellow-powder presented average particles size of 180±66nm, while the white-powder presented particles size of 198±73nm. After sintering, full dense ceramics with tetragonal phase were obtained. The linear shrinkage of the yellow and white-layer was 22.75% and 22.05% respectively. This difference in shrinkage is important in the machining of prostheses in ceramic CAD/CAM systems, because they lead to difficulties in adapting this customized prosthesis in patients.

In Situ X-Ray Diffraction Studies of Crystallization Growth Behavior in ZnO-Bi2O3-B2O3 Glass as a Route to Functional Optical Devices

MRS Advances ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 563-567 ◽  
Author(s):  
Quentin Altemose ◽  
Katrina Raichle ◽  
Brittani Schnable ◽  
Casey Schwarz ◽  
Myungkoo Kang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Crystal Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Xrd ◽  
Dsc Measurements ◽  
Transmission Window

ABSTRACTTransparent optical ZnO–Bi2O3–B2O3 (ZBB) glass-ceramics were created by the melt quenching technique. In this work, a melt of the glass containing stoichiometric ratios of Zn/Bi/B and As was studied. Differential scanning calorimeter (DSC) measurements was used to measure the thermal behavior. VIS/NIR transmission measurements were used to determine the transmission window. X-ray diffraction (XRD) was used to determine crystal phase. In this study, we explore new techniques and report a detailed study of in-situ XRD of the ZBB composition in order to correlate nucleation temperature, heat treatment temperature, and heat treatment duration with induced crystal phase.

scholarly journals Bone bonding ability of some borate bio-glasses and their corresponding glass-ceramic derivatives

2012 ◽  
Vol 6 (4) ◽  
pp. 183-192 ◽  
Author(s):  
Fatma Margha ◽  
Amr Abdelghany
Keyword(s):  
Heat Treatment ◽  
Fourier Transform ◽  
Glass Ceramic ◽  
Glass Composition ◽  
Glass Ceramics ◽  
Soda Lime ◽  
Phosphate Solution ◽  
Borate Glasses ◽  
X Ray Diffraction ◽  
X Ray

Ternary borate glasses from the system Na2O?CaO?B2O3 together with soda-lime-borate samples containing 5 wt.% of MgO, Al2O3, SiO2 or P2O5 were prepared. The obtained glasses were converted to their glass-ceramic derivatives by controlled heat treatment. X-ray diffraction was employed to investigate the separated crys?talline phases in glass-ceramics after heat treatment of the glassy samples. The glasses and corresponding glass-ceramics after immersion in water or diluted phosphate solution for extended times were characterized by the grain method (adopted by several authors and recommended by ASTM) and Fourier-transform infrared spectra to justify the formation of hydroxyapatite as an indication of the bone bonding ability. The influence of glass composition on bioactivity potential was discussed too.

Structure Characterization of Sintered CaO-Al2O3-SiO2 Glass-Ceramic Reinforced with Spodumene

2013 ◽  
Vol 834-836 ◽  
pp. 309-314
Author(s):  
Zi Fan Xiao ◽  
Jin Shu Cheng ◽  
Jun Xie
Keyword(s):  
Glass Ceramic ◽  
Energy Dispersive Spectrometry ◽  
Crystal Size ◽  
Bending Strength ◽  
Glass Ceramics ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray

A glass-ceramic belonging to the CaO-Al2O3-SiO2(CAS) system with different composition of spodumene and doping the Li2O with amount between 0~2.5 % (mass fraction) were prepared by onestage heat treatment, under sintering and crystallization temperature at 1120 °C for two hours. In this paper, differential thermal analysis, X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry and bending strength test were employed to investigate the microstructure and properties of all samples. β-wollastonite crystals were identified as the major crystalline phases, and increasing Li2O was found to be benefit for the crystallization and tiny crystalline phases remelting, resulting in the content of major crystalline phases increased first and then decreased with increasing the expense of spodumene. Meanwhile, the crystal size can be positively related with the content of Li2O. The preferable admixed dosage of spodumene can be obtained, besides the strength of glass-ceramics can be more than 90 MPa.

The Effects of Preparation Conditions And Chemical Composition On CMAS Glass Ceramics With One Step Process

2021 ◽  
Author(s):  
Yuliang Guo ◽  
Huixin Jin ◽  
Yuandan Xiao ◽  
Huahao Song ◽  
Shangjiefu Wang
Keyword(s):  
Solid Waste ◽  
Theoretical Basis ◽  
Chromium Content ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
Crystallization Activation Energy ◽  
X Ray ◽  
Preparation Conditions ◽  
Treatment Conditions ◽  
One Step

Abstract Based on the composition of Cr-doped solid waste, other oxides were added to adjust the composition to prepare glass-ceramics with on step composition, and the effect of heat treatment system (including temperature and holding time), chromium content, MnO and Fe2O3 doped on the crystallization and physical properties of glass-ceramics was studied. The samples were characterized by X-ray diffraction, differential thermal analysis and scanning electron microscopy. The results show that the best treatment conditions are 1090 ℃ for 4h, and the amount of dissolved chromium reaches 5%. The main crystallization phase is diopside and anorthite. The hardness and chemical stability of the material were measured. The doping of MnO and Fe2O3 increases the crystallization activation energy of glass ceramics, and makes the crystal phase more uniform as the SEM results. This experiment provides a theoretical basis for the preparation of CMAS glass ceramics from chromium containing solid waste.

Connector Architecture for Computer-Assisted Design and Manufacturing Systems

2004 ◽  
Vol 20 (04) ◽  
pp. 262-268
Author(s):  
Reinhard M. Staebler ◽  
Bryan J. Miller ◽  
Paul J. Rakow ◽  
Thomas Koch
Keyword(s):  
Data Exchange ◽  
Manufacturing Systems ◽  
Reference Model ◽  
Computer Assisted ◽  
Computer Assisted Design ◽  
Cad Cam ◽  
Flexible Integration ◽  
Business Objects ◽  
Negative Impacts ◽  
Cam Systems

Flexible integration concepts for computer-assisted design (CAD) and manufacturing (CAM) systems have been identified as a key to let shipyards select and implement best-in-class software components for their CAD and CAM operations. Current implementations are dominated by bilateral links based on proprietary data exchange formats and are too complex to upgrade parts of a CAD/CAM infrastructure without negative impacts on the other parts. This paper describes the ongoing development of a connector architecture for CAD and CAM systems in shipbuilding. The architecture decouples CAD and CAM systems on the basis of a flexible integration technology, utilizing XML data exchange, lightweight directory access protocol (LDAP), and message-based communication. An enterprise reference model describing all relevant shipbuilding business objects forms the basis for the integration. So-called adapters connect the various CAD and CAM systems to the architecture. An automatic nesting solution is presented as a sample business solution in the connector architecture environment.

scholarly journals Five-fold twinned β-PbF2 nanocrystals in oxyfluoride glass ceramics

RSC Advances ◽  
2018 ◽  
Vol 8 (71) ◽  
pp. 40787-40793 ◽  
Author(s):  
Yuao Guo ◽  
Lijuan Zhao ◽  
Yuting Fu ◽  
Pan Dong ◽  
Liying Guo ◽  
...  
Keyword(s):  
Glass Ceramics ◽  
Lanthanide Ions ◽  
X Ray Diffraction ◽  
Oxyfluoride Glass ◽  
X Ray ◽  
Trivalent Lanthanide ◽  
Quenching Method

Oxyfluoride glass ceramics (GCs) doped with trivalent lanthanide ions (Ln3+) have been prepared using a conventional melting–quenching method and studied by X-ray diffraction (XRD).

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