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Eman Z Al-Shehri, Afnan O Al-Zain, Alaa H Sabrah, Sarah S Al-Angari, Laila Al Dehailan, George J Eckert, Mutlu Özcan, Jeffrey A Platt, Marco C Bottino
OBJECTIVES: To determine the combined effect of fatigue cyclic loading and thermocycling (CLTC) on the shear bond strength (SBS) of a resin cement to zirconia surfaces that were previously air-abraded with aluminum oxide (Al2O3) particles at different pressures. MATERIALS AND METHODS: Seventy-two cuboid zirconia specimens were prepared and randomly assigned to 3 groups according to the air-abrasion pressures (1, 2, and 2.8 bar), and each group was further divided into 2 groups depending on aging parameters (n = 12)...
August 2017: Restorative Dentistry & Endodontics
Dušan Bučevac, Tomaž Kosmač, Andraž Kocjan
The yttrium-segregation-dependent phase partitioning and residual stress development that influence both the aging and the fracture behaviour in 3Y-TZP bioceramics were studied by sintering alumina-free 3Y-TZP, varying the sintering temperature and the time, to yield ceramics with identical grain size distributions, but with different phase compositions. The structure and stability of the resulting tetragonal phases, in the form of transformable, yttria-lean t-ZrO2 (YLZ) and non-transformable, yttria-rich t"-ZrO2 and/or t'-ZrO2 (YRZ), were studied by X-ray diffraction (XRD) and focused ion beam scanning electron microscopy (FIB-SEM)...
August 11, 2017: Acta Biomaterialia
Fabian Hüttig, Jan P Keitel, Andreas Prutscher, Sebastian Spintzyk, Andrea Klink
PURPOSE: This clinical trial tested bilayered restorations based on ceria-stabilized tetragonal zirconia/alumina frameworks veneered with feldspathic ceramic. MATERIALS AND METHODS: A total of 67 crowns and 40 fixed dental prostheses (FDPs) were luted in 57 patients with self-etching/self-adhesive composite resin cement. Dental status and integrity of restorations were evaluated at 2 weeks, 6 months, and then annually. RESULTS: A total of 66 crowns and 36 FDPs (88% posterior) survived for success rates of 93...
August 14, 2017: International Journal of Prosthodontics
Tzu-Tien Huang, Shun-Wen Cheng, Chia-Liang Tsai, Guey-Sheng Liou
A series of novel polyimidothioethers (PITEs) and the respective polymer hybrids of titania or zirconia with fantastic thermal stability and optical properties have been successfully prepared. These colorless PITEs with high transparency were synthesized by Michael polyaddition from commercially available dithiol and bismaleimides monomers. The PITE with sulfide and hydroxyl groups (S-OH) and the corresponding hybrid films declare ultra-lowest birefringence value of 0.002 and tunable refractive index (1.65-1...
August 11, 2017: Scientific Reports
W C Yang, Y T Xie, W K Zhu, K Park, A P Chen, Y Losovyj, Z Li, H M Liu, M Starr, J A Acosta, C G Tao, N Li, Q X Jia, J J Heremans, S X Zhang
While pyrochlore iridate thin films are theoretically predicted to possess a variety of emergent topological properties, experimental verification of these predictions can be obstructed by the challenge in thin film growth. Here we report on the pulsed laser deposition and characterization of thin films of a representative pyrochlore compound Bi2Ir2O7. The films were epitaxially grown on yttria-stabilized zirconia substrates and have lattice constants that are a few percent larger than that of the bulk single crystals...
August 10, 2017: Scientific Reports
Panos Papaspyridakos, Kiho Kang, Catherine DeFuria, Sarah Amin, Yukio Kudara, Hans-Peter Weber
OBJECTIVE: To illustrate a digital workflow in full-arch implant rehabilitation with minimally veneered monolithic zirconia and to report the outcomes including technical complications. CLINICAL CONSIDERATIONS: Three patients (5 edentulous arches) received full-arch fixed implant rehabilitation with monolithic zirconia and mild facial porcelain veneering involving a digital workflow. The incisal edges and occluding surface areas were milled out of monolithic zirconia to reduce the possibility of chipping...
August 9, 2017: Journal of Esthetic and Restorative Dentistry
Andrée Nilsson, Lars-Åke Johansson, Christina Lindh, Anders Ekfeldt
BACKGROUND: Studies have reported an increased risk for fractures of zirconia abutments compared with titanium abutments. PURPOSE: The aim of this study was to evaluate single-tooth implant restorations with one-piece yttria-stabilized internal zirconia abutments on narrow and regular diameter implants up to 6 years after insertion. MATERIAL AND METHODS: This study comprises 52 consecutively treated patients, with a median age of 19 years...
August 9, 2017: Clinical Implant Dentistry and related Research
P Pandoleon, E Kontonasaki, N Kantiranis, N Pliatsikas, P Patsalas, L Papadopoulou, T Zorba, K M Paraskevopoulos, P Koidis
OBJECTIVE: Yttrium-stabilized zirconia is susceptible to low temperature degradation after interaction with water. Various mechanisms by which water molecules destabilize the tetragonal phase have been proposed, while the concept of yttrium depletion by the incorporation of hydroxyl ions in the crystalline structure either through the formation of YOH/ZrOH bonds or small α-Y(OH)3 crystallites, is prevailing. The present study was performed to investigate the surface alterations on a 3Y-TZP dental ceramic during the process of in-vitro aging and to further explore the yttrium depletion mechanism that occurs upon interaction with water...
August 5, 2017: Dental Materials: Official Publication of the Academy of Dental Materials
Nazmiye Sen, Yesim Olcer Us
STATEMENT OF PROBLEM: Achieving natural tooth appearance with sufficient mechanical strength is one of the most challenging issues of computer-assisted design and computer-assisted manufacturing (CAD-CAM) materials. However, limited evidence is available regarding their optical and mechanical properties for proper and evidence-based material selection in clinical practice. PURPOSE: The purpose of this in vitro study was to assess and compare the translucency and biaxial flexural strength of 5 monolithic CAD-CAM restorative materials...
August 4, 2017: Journal of Prosthetic Dentistry
Pei Wang, Chunbo Tang, Yi Tang, Yunong Wu
The technique of immediate implantation has been widely used to reduce treatment time and bone loss after extraction. However, immediate implant placement in infected extraction sockets is generally contraindicated. This clinical report describes a treatment protocol for immediate implantation after the extraction of teeth with generalized chronic periodontitis. The technique used for the oral rehabilitation used computer-assisted design and computer-assisted manufacturing (CAD-CAM) titanium frameworks and cemented zirconia crowns...
August 4, 2017: Journal of Prosthetic Dentistry
Miha Brezavšček, Ahmed Fawzy, Maria Bächle, Taskin Tuna, Jens Fischer, Wael Att
OBJECTIVE: Improvements in the bioactivity of zirconia implants for accelerated healing and reduced morbidity have been of continuing interest in the fields of dentistry and orthopedic surgery. The aim of the present study was to examine whether UV treatment increases the osteoconductivity of zirconia-based materials. MATERIALS AND METHODS: Smooth and rough zirconia-based disks and cylindrical implants were treated with UV light for 15 min and subsequently placed in rat femurs...
November 24, 2016: Materials
Taro Shimonosono, Hikari Imada, Hikaru Maeda, Yoshihiro Hirata
The gas permeability of α-alumina, yttria-stabilized zirconia (YSZ), and silicon carbide porous ceramics toward H₂, CO₂, and H₂-CO₂ mixtures were investigated at room temperature. The permeation of H₂ and CO₂ single gases occurred above a critical pressure gradient, which was smaller for H₂ gas than for CO₂ gas. When the Knudsen number (λ/r ratio, λ: molecular mean free path, r: pore radius) of a single gas was larger than unity, Knudsen flow became the dominant gas transportation process...
November 16, 2016: Materials
Susanne Merk, Christina Wagner, Veronika Stock, Marlis Eichberger, Patrick R Schmidlin, Malgorzata Roos, Bogna Stawarczyk
This study investigates the retention load (RL) between ZrO₂ primary crowns and secondary polyetheretherketone (PEEK) crowns made by different fabrication methods with three different tapers. Standardized primary ZrO₂ crowns were fabricated with three different tapers: 0°, 1°, and 2° (n = 10/group). Ten secondary crowns were fabricated (i) milled from breCam BioHPP blanks (PM); (ii) pressed from industrially fabricated PEEK pellets (PP) (BioHPP Pellet); or (iii) pressed from granular PEEK (PG) (BioHPP Granulat)...
November 8, 2016: Materials
Sebastian Spintzyk, Kikue Yamaguchi, Tomofumi Sawada, Christine Schille, Ernst Schweizer, Masahiko Ozeki, Jürgen Geis-Gerstorfer
This study evaluated the bond strength of veneering porcelain with an experimental conditioner-coated zirconia. Pre-sintered Y-TZP specimens (n = 44) were divided in two groups based on conditioning type. After sintering, all sample surfaces were sandblasted and layered with veneering porcelain. Additionally, half of the specimens in each group underwent thermal cycling (10,000 cycles, 5-55 °C), and all shear bond strengths were measured. After testing, the failure mode of each fractured specimen was determined...
September 8, 2016: Materials
Daniel Roehrens, Ute Packbier, Qingping Fang, Ludger Blum, Doris Sebold, Martin Bram, Norbert Menzler
In this study we report on the development and operational data of a metal-supported solid oxide fuel cell with a thin film electrolyte under varying conditions. The metal-ceramic structure was developed for a mobile auxiliary power unit and offers power densities of 1 W/cm² at 800 °C, as well as robustness under mechanical, thermal and chemical stresses. A dense and thin yttria-doped zirconia layer was applied to a nanoporous nickel/zirconia anode using a scalable adapted gas-flow sputter process, which allowed the homogeneous coating of areas up to 100 cm²...
September 8, 2016: Materials
Seon-Mi Byeon, Yong-Seok Jang, Min-Ho Lee, Tae-Sung Bae
This study examined the effects of 3 mol % yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) ceramic surface treatments on the tensile bond strength and surface characteristics of enamel. To measure the tensile bond strength, the 3Y-TZP and tooth specimens were manufactured in a mini-dumbbell shape and divided into four groups based on the type of 3Y-TZP surface treatment: polishing (P), 110 µm alumina sandblasting (S), 110 µm alumina sandblasting combined with selective infiltration etching (SS), and 110 µm alumina sandblasting combined with MDP (10-methacryloyloxydecyl dihydrogen phosphate)-containing silane primer (SP)...
August 18, 2016: Materials
Flavia Bollino, Emilia Armenia, Elisabetta Tranquillo
Zirconia (ZrO₂) and zirconia-based glasses and ceramics are materials proposed for use in the dental and orthopedic fields. In this work, ZrO₂ glass was modified by adding different amounts of bioactive and biocompatible hydroxyapatite (HAp). ZrO₂/HAp composites were synthesized via the sol-gel method and heated to different temperatures to induce modifications of their chemical structure, as ascertained by Fourier transform infrared spectroscopy (FTIR) analysis. The aim was to investigate the effect of both HAp content and heating on the biological performances of ZrO₂...
July 5, 2017: Materials
Paola Taddei, Eleonora Pavoni, Saverio Affatato
Biolox(®) delta has been widely used in joint replacements thanks to its high strength and wear resistance. In this study, eleven Biolox(®) delta femoral head retrievals affected by metal transfer (MT) were analysed by Raman spectroscopy to estimate the tetragonal to monoclinic zirconia phase transformation, whose occurrence may compromise ceramic chemical stability and mechanical strength. The residual stress state was evaluated by both Raman and photoemission spectroscopy. Vm monoclinic zirconia contents were higher near the centre of the articulating surface and in the MT area than in the border control area of the retrievals...
July 3, 2017: Materials
Xiaodong Chen, Ulf Betke, Stefan Rannabauer, Paul Clemens Peters, Gerrit Maximilian Söffker, Michael Scheffler
The combination of high strength and toughness, excellent wear resistance and moderate density makes zirconia-toughened alumina (ZTA) a favorable ceramic, and the foam version of it may also exhibit excellent properties. Here, ZTA foams were prepared by the polymer sponge replication method. We developed an immersion infiltration approach with simple equipment and operations to fill the hollow struts in as-prepared ZTA foams, and also adopted a multiple recoating method (up to four cycles) to strengthen them...
July 1, 2017: Materials
Roberto Lopez-Píriz, Adolfo Fernández, Lidia Goyos-Ball, Sergio Rivera, Luis A Díaz, Manuel Fernández-Domínguez, Catuxa Prado, José S Moya, Ramón Torrecillas
Although titanium remains as the prevalent material in dental implant manufacturing new zirconia-based materials that overcome the major drawbacks of the standard 3Y-yttria partially-stabilized zirconia (Y-TZP) are now emerging. In this study, a new ceramic nanocomposite made of alumina and ceria-stabilized TZP (ZCe-A) has been used to produce dental implants with the mechanic and topographic characteristics of a pilot implant design to evaluate bone and soft tissue integration in a dog model (n = 5). Histological cross-section analysis of the implanted ceramic fixations (n = 15) showed not only perfect biocompatibility, but also a high rate of osseous integration (defined as the percentage of bone to implant contact) and soft tissue attachment...
June 3, 2017: Materials
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