Implants for surgery. Ceramic materials based on yttria-stabilized tetragonal zirconia (Y-TZP)

2009 ◽  
Keyword(s):  
Tetragonal Zirconia ◽  
Ceramic Materials

Ceramics for the Immobilization of Plutonium and Americium: Current Progress of R&D of the V.G. Khlopin Radium Institute

2003 ◽  
Vol 807 ◽  
Author(s):  
Evgeniy B. Anderson ◽  
Boris E. Burakov
Keyword(s):  
Sol Gel ◽  
Tetragonal Zirconia ◽  
Ceramic Materials ◽  
Khlopin Radium Institute ◽  
Radium Institute ◽  
Crystalline Materials ◽  
Synthesis Conditions ◽  
Mixed Oxide Fuel ◽  
Air Atmosphere ◽  
Environmentally Safe

ABSTRACTSince 1990, the Laboratory of Applied Mineralogy and Radiogeochemistry of the V.G. Khlopin Radium Institute (KRI) has been developing several different types of crystalline host-phases acceptable for the economically feasible and environmentally safe immobilization of actinide wastes. We proposed that ceramics that are based on host phases similar to naturally occurring accessory minerals including zircon, (Zr,Hf,…)SiO4; hafnon, (Hf,Zr,…)SiO4; baddeleyite (monoclinic zirconia), (Zr,Hf,…)O2; tazheranite (cubic zirconia), (Zr,Hf,Ca,Ti,…)O2; garnet, (Ca,Fe,Gd,…)3(Al,Fe,Si,…)5O12; perovskite, (Ca,Gd,…)(Al,Fe,Ti,…)O3, and monazite, (La,Ce,…)PO4, are the most efficient materials for actinide immobilization in deep geological formations. Solid solution of Pu in zirconia, (Zr,Pu)O2, could be used as a ceramic nuclear fuel that is competitive with mixed oxide fuel (MOX). To date, the following crystalline materials doped with 239Pu, 238Pu and 243Am have been successfully synthesized and studied at KRI: zircon; hafnon; cubic and tetragonal zirconia; monazite; aluminate garnet and perovskite. The maximum actinide loading was (in wt.% el.): 239Pu -37; 238Pu-10; 243Am-23. All Pu-Am-doped samples were made in air atmosphere under glove boxes conditions. Polycrystalline (ceramic) materials were made by sintering or melting of sol-gel, co-precipitated hydroxides, oxalates and phosphates or ground oxide precursors; single crystals were grown by a flux method. It was demonstrated that all ceramic samples obtained are characterized by high chemical durability and typical normalized actinide losses in deionized water at 90°C do not exceed 10−2–10−3 g/m2 (without correction for ceramic porosity). However, investigation of long-term behavior of ceramic waste forms requires taking into account the results of accelerated radiation damage study and modeling of ceramic alteration by underground solutions. The principal features of Pu-Am-doped samples obtained so far at KRI and their synthesis conditions are discussed.

scholarly journals Surface Modifications of Dental Ceramic Implants with Different Glass Solder Matrices:In VitroAnalyses with Human Primary Osteoblasts and Epithelial Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Jana Markhoff ◽  
Enrico Mick ◽  
Aurica Mitrovic ◽  
Juliane Pasold ◽  
Katharina Wegner ◽  
...  
Keyword(s):  
Solder Matrix ◽  
Tetragonal Zirconia ◽  
Ceramic Materials ◽  
Bone Cell ◽  
Titanium Implants ◽  
Type I ◽  
Dental Surgery ◽  
Procollagen Type ◽  
Procollagen Type I ◽  
Ceramic Implants

Ceramic materials show excellent esthetic behavior, along with an absence of hypersensitivity, making them a possible alternative implant material in dental surgery. However, their surface properties enable only limited osseointegration compared to titanium implants. Within this study, a novel surface coating technique for enhanced osseointegration was investigated biologically and mechanically. Specimens of tetragonal zirconia polycrystal (TZP) and aluminum toughened zirconia (ATZ) were modified with glass solder matrices in two configurations which mainly consisted of SiO2, Al2O3, K2O, and Na2O. The influence on human osteoblastic and epithelial cell viability was examined by means of a WST-1 assay as well as live/dead staining. A C1CP-ELISA was carried out to verify procollagen type I production. Uncoated/sandblasted ceramic specimens and sandblasted titanium surfaces were investigated as a reference. Furthermore, mechanical investigations of bilaterally coated pellets were conducted with respect to surface roughness and adhesive strength of the different coatings. These tests could demonstrate a mechanically stable implant coating with glass solder matrices. The coated ceramic specimens show enhanced osteoblastic and partly epithelial viability and matrix production compared to the titanium control. Hence, the new glass solder matrix coating could improve bone cell growth as a prerequisite for enhanced osseointegration of ceramic implants.

Low Temperature Degradation of Y-TZP Ceramic for Dental Applications

2013 ◽  
Vol 873 ◽  
pp. 241-249
Author(s):  
Zhi Kai Wu ◽  
Ning Li ◽  
Wan Qian Zhao ◽  
Jia Zhen Yan
Keyword(s):  
Low Temperature ◽  
Substantial Reduction ◽  
Tetragonal Zirconia ◽  
Ceramic Materials ◽  
Dental Ceramics ◽  
All Ceramic ◽  
Long Time ◽  
Core Thickness ◽  
Dental Applications

Yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic has been recently introduced into prosthetic dentistry for the fabrication of crowns and fixed partial dentures (FPDs). The mechanical properties of Y-TZP are the highest ever reported for the all-ceramic materials. This is favorable for the fabrication of multi-unit posterior bridges and the substantial reduction in core thickness. However, Y-TZP ceramic is susceptible to low temperature degradation (LTD), which is detrimental to the long-time survival and aesthetics of zirconia restorations in vivo. This review summarizes the characterization, mechanisms, and influencing factors of the LTD in dental Y-TZP ceramic. In addition, the recent trend of exploring high aging resistant zirconia-based dental ceramics is discussed.

scholarly journals Review Article: Zirconia surface bone graft implant with Ultraviolet Stimulation works toward Accelerating Bone Healing

2019 ◽  
Vol 7 (11_suppl6) ◽  
pp. 2325967119S0046
Author(s):  
Adriel Benedict Haryono ◽  
Yoyos Dias Ismiarto
Keyword(s):  
Literature Review ◽  
Bone Healing ◽  
Bone Growth ◽  
Cell Attachment ◽  
Biomedical Application ◽  
Tetragonal Zirconia ◽  
Ceramic Materials ◽  
Bone Grafts ◽  
Bone Substitutes ◽  
Transformation Toughening

Biomedical zirconia was introduced in 1969 into medicine to solve the problem of alumina brittleness in hip replacement procedures and has since been used for various joint replacement appliances in orthopedic surgery. The most frequently-studied material is yttrium-stabilized zirconia, which is also known as tetragonal zirconia polycrystal (TZP). Y-TZP presents various interesting characteristics, such as low porosity, high density and high bending and compression strength, proving that it is suitable for biomedical application. UV-treated zirconia surfaces exhibited an enhanced osteoblast response, which was characterized by an accelerated and augmented cell attachment, accelerated cell spread and cytoskeletal development with increased proliferation. The purpose of this paper is to identify which method of treatment of zirconia material implant & ultraviolet stimulation effect for bone healing is the most effective and efficient based on literature review. Bone grafts are available in a variety of substances. These bone substitutes can be biological (natural) or synthetic. Re-absorption is also essential for bone growth. Specific cells continuously break down bones and rebuild them. Substitutes that break down too quickly are not suitable for bone grafts, as they do not allow enough time for the new bone to grow. From our literature review, Zirconia is one of the biomaterials that have a bright future because of its high mechanical strength and fracture toughness. Zirconia ceramics have several advantages over other ceramic materials due to the transformation toughening mechanisms operating in their microstructure that can be expressed in components made out of them. UV treatment substantially enhances the osteogenesis process, resulting in a greater amount of peri-implant bone, as well as an increased strength of bone-zirconia integration.

Analytical TEM of grain boundary phases in yttria-zirconia ceramics

1987 ◽  
Vol 45 ◽  
pp. 166-167
Author(s):  
M.L. Mecartney ◽  
P. Angelini
Keyword(s):  
Grain Boundary ◽  
Tetragonal Zirconia ◽  
Ceramic Materials ◽  
Liquid Phase Sintering ◽  
Raw Material ◽  
Aluminosilicate Glass ◽  
Microstructural Development ◽  
Ionic Conductors ◽  
Zirconia Ceramics ◽  
Amorphous Silicate

Yttria-zirconia ceramics have a broad range of applications, from use as structural materials (tetragonal zirconia) to ionic conductors (cubic zirconia). Similar to many ceramic materials, these zirconia ceramics often contain small amounts of amorphous silicate phases at grain boundaries and multiple grain junctions. These phases are a result of impurities, introduced during processing or from the original raw material, or are deliberate additions to aid in the densification via liquid phase sintering. Despite the universality of these grain boundary phases, as of yet little work has been undertaken to understand their effect on the microstructural development, chemistry, and physical properties of the materials. We report here our results on analyzing a series of yttria doped zirconia ceramics to which deliberate additions of various glass phases have been added.Samples were fabricated from zirconia powders which contained 3 mol% yttria and 8 mol% yttria. Aluminosilicate glass or borosilicate glass (5 wt%) was added to the powders before sintering. The samples were hot-isostatically pressed at 1650°C for 1-100 minutes.

Transformation toughening of glass ceramics

1987 ◽  
Vol 2 (6) ◽  
pp. 801-804 ◽  
Author(s):  
D. R. Clarke ◽  
B. Schwartz
Keyword(s):  
Glass Ceramic ◽  
Tetragonal Zirconia ◽  
Glass Ceramics ◽  
Ceramic Materials ◽  
Nucleation Event ◽  
Transformation Toughening ◽  
Glass Ceramic Materials ◽  
Polycrystalline Ceramic ◽  
Cordierite Glass ◽  
Processing Techniques

The utilization of transformation toughening has hitherto been restricted to increasing the fracture resistance of polycrystalline ceramic materials. Although a number of investigators have attempted to extend the concept to toughening glasses and glass ceramics with tetragonal zirconia, no successful reports have been published. It is argued that the approaches employed are inevitably limited primarily because they do not take into account the necessity of nucleating the tetragonal-to-monoclinic transformation away from the crack tip itself. By concentrating on the nucleation event and using standard ceramic processing techniques, it has been demonstated that transformation toughening can be used to increase the toughness of glass-ceramic materials, and this approach is illustrated by increasing the fracture toughness of a cordierite glass ceramic.

scholarly journals Ceramic Materials and Technologies Applied to Digital Works in Implant-Supported Restorative Dentistry

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1964
Author(s):  
Se-Wook Pyo ◽  
Dae-Joon Kim ◽  
Jung-Suk Han ◽  
In-Sung Luke Yeo
Keyword(s):  
Computer Aided Design ◽  
Tetragonal Zirconia ◽  
Glass Ceramics ◽  
Ceramic Materials ◽  
Dental Restoration ◽  
Numerical Control ◽  
Optical Scanning ◽  
Computer Based ◽  
Digital Algorithms ◽  
Aided Design

Computer-aided design and manufacturing technology has been closely associated with implant-supported restoration. The digital system employed for prosthodontic restorations comprises data acquisition, processing, and manufacturing using subtractive or additive methods. As digital implantology has developed, optical scanning, computer-based digital algorithms, fabricating techniques, and numerical control skills have all rapidly improved in terms of their accuracy, which has resulted in the development of new ceramic materials with advanced esthetics and durability for clinical application. This study reviews the application of digital technology in implant-supported dental restoration and explores two globally utilized ceramic restorative materials: Yttria-stabilized tetragonal zirconia polycrystalline and lithium disilicate glass ceramics.

scholarly journals Flexural Strength of Different Monolithic Computer-Assisted Design and Computer-Assisted Manufacturing Ceramic Materials upon Different Thermal Tempering Processes

2020 ◽  
Vol 14 (04) ◽  
pp. 566-574
Author(s):  
Niwut Juntavee ◽  
Pithiwat Uasuwan
Keyword(s):  
Flexural Strength ◽  
Tetragonal Zirconia ◽  
Ceramic Materials ◽  
Bending Test ◽  
Lithium Silicate ◽  
Computer Assisted ◽  
Three Point Bending ◽  
Significant Difference ◽  
Monolithic Zirconia ◽  
Thermal Tempering

Abstract Objective Strength of ceramics related with sintering procedure. This study investigated the influence of different tempering processes on flexural strength of three monolithic ceramic materials. Materials and Methods  Specimens were prepared in bar-shape (width × length × thickness = 4 × 14 × 1.2 mm) from yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP, inCoris TZI [I]), zirconia-reinforced lithium silicate (ZLS, Vita Suprinity [V]), and lithium disilicate (LS2, IPS e.max CAD [E]), and sintered with different tempering processes: slow (S), normal (N), and fast (F) cooling procedure (n = 15/group). Flexural strength (σ) was determined using three-point bending test apparatus at 1 mm/min crosshead speed. Statistical Analysis  The analysis of variance and Bonferroni’s multiple comparisons were determined for significant difference (α = 0.05). Weibull analysis was applied for survival probability, Weibull modulus (m), and characteristics strength (σo). Microstructures were evaluated with scanning electron microscope and X-ray diffraction. Results  The mean ± standard deviation (MPa) of σ, m, and σo were: 1,183.98 ± 204.26, 6.23, 1,271.80 for IS; 1,084.43 ± 204.79, 5.76, 1,170.08 for IN; 777.19 ± 99.77, 8.78, 819.96 for IF; 267.15 ± 32.71, 9.11, 281.48 for VS; 218.43 ± 38.46, 6.40, 234.23 for VN; 252.67 ± 37.58, 7.20, 269.23 for VF; 392.09 ± 37.91, 11.37, 409.23 for ES; 378.88 ± 55.38, 7.45, 403.11 for EN, and 390.94 ± 25.34, 16.00, 403.51 for EF. Thermal tempering significantly affected flexural strength of Y-TZP (p < 0.05), but not either ZLS or LS2 (p > 0.05). Y-TZP indicated significantly higher flexural strength upon slow tempering than others. Conclusion  Enhancing flexural strength of Y-TZP can be achieved through slow tempering process and was suggested as a process for monolithic zirconia. Strengthening of ZLS and LS2 cannot be accomplished through tempering; thus, either S-, N-, or F- tempering procedure can be performed. Nevertheless, to minimize sintering time, rapid thermal tempering is more preferable for both ZLS and LS2.

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