Porcelain bonding to novel Co–Cr alloys: Influence of interfacial reactions on phase stability, plasticity and adhesion

Li, Kai Chun; Tran, L.; Prior, David J.; Waddell, John Neil; Swain, Michael V.

doi:10.1016/j.dental.2016.09.008

Cited by 18 publications

(9 citation statements)

References 26 publications

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“…The mechanical properties of the alloy can be influenced by porosity, grain size, and second-phase particles [ 25 , 26 ]. Metal-ceramic bond strength is related to Young’s (elastic) modulus, chemical bonding, mechanical interlocking, compressive bonding, and van der Waals forces, among those, chemical bonding dominates [ 6 , 27 , 28 , 29 ]. The chemical bonding can be changed when an oxide layer forms on the surface.…”

Section: Introductionmentioning

confidence: 99%

Comparative Analysis of Mechanical Properties and Metal-Ceramic Bond Strength of Co-Cr Dental Alloy Fabricated by Different Manufacturing Processes

et al. 2018

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Cobalt-chromium (Co-Cr) alloy is a widely used base material for dental fixed prostheses. These restorations can be produced through casting technique, subtractive or additive manufacturing technologies. However, limited information is available regarding the influence of manufacturing techniques on the properties of Co-Cr alloy since most studies used different chemical compositions of Co-Cr alloy for different manufacturing methods. This study compares the mechanical properties, metal-ceramic bond strength, and microstructures of specimens produced by casting, milling, and selective laser melting (SLM) from one single Co-Cr alloy composition. The mechanical properties of the alloy were investigated by tensile and Vickers hardness tests, and metal-ceramic bond strength was determined by three-point bending. Scanning electron microscopy (SEM) with backscattered electron (BSE) images and optical microphotographs were used to analyze the surface microstructures. Compared with the casting and milling techniques, SLM Co-Cr alloy specimens indicated enhanced mechanical properties and comparable metal-ceramic bond strength. Besides, the microstructures of the SLM specimens showed finer grains with more second phase particles than the casting and milling specimens. The results of our study indicate that SLM might be superior to traditional techniques for the manufacturing of fixed dental restorations.

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Section: Introductionmentioning

confidence: 99%

Comparative Analysis of Mechanical Properties and Metal-Ceramic Bond Strength of Co-Cr Dental Alloy Fabricated by Different Manufacturing Processes

et al. 2018

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“…These results are different from the general pearlite-or plate-like martensitic phase transformation ((111) γ//(0001) ε) of Co-Cr alloys when the aging treatment was proceeded [25]. Previous EBSD studies also showed a continuously developed ε-phase near the porcelain-fused-to-metal (Co-Cr alloys) interface [22,26,27]. The Cr-based ε-phase (yellow) in the phase map were indexed as the long ε-phase of the a and c axes (a: 3.7441; c: 12.1493) rather than the crystal lattice values (a: 2.5060; c: 4.0690) of W-Mo-Nb-rich precipitate dendrites.…”

Section: Crystallographic Featuresmentioning

confidence: 70%

Application of a Novel CVD TiN Coating on a Biomedical Co–Cr Alloy: An Evaluation of Coating Layer and Substrate Characteristics

et al. 2020

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Titanium nitride (TiN) was deposited on the surface of a cobalt–chromium (Co–Cr) alloy by a hot-wall type chemical vapor deposition (CVD) reactor at 850 °C, and the coating characteristics were compared with those of a physical vapor deposition (PVD) TiN coating deposited on the same alloy at 450 °C. Neither coating showed any reactions at the interface. The face-centered cubic (fcc) structure of the alloy was changed into a hexagonal close-packed (hcp) phase, and recrystallization occurred over at 10 μm of depth from the surface after CVD coating. Characteristic precipitates were also generated incrementally depending on the depth, unlike the precipitates in the matrix of the as-cast alloy. On the other hand, the microstructure and phase of the PVD-coated alloy did not change. Depth-dependent nano-hardness measurements showed a greater increase in hardness in the recrystallization zone of the CVD-coated alloy than in the bulk center of the alloy. The CVD coating showed superior adhesion to the PVD coating in the progressive scratch test. The as-cast, PVD-coated, and CVD-coated alloys all showed negative cytotoxicity. Within the limitations of this study, CVD TiN coating to biomedical Co–Cr alloy may be considered a promising alternative to PVD technique.

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“…16,17 Nevertheless, in most of the studies to date, exploring the differences in the strength of porcelain bonds to Co-Cr alloys fabricated by different technologies, there were compositional differences between the tested alloys. [18][19][20][21][22][23][24] This is probably due to material limitations and the tendency of the manufacturers to slightly modify the composition of the alloys that are to be processed through different technological procedures. In addition, F. Pitt and M. Ramulu 15 showed that a fine metal microstructure exhibits more rapid oxidation kinetics than does a coarser microstructure.…”

Section: Introductionmentioning

confidence: 99%

The bond strength of dental porcelain to cobalt-chromium alloys fabricated by casting, milling and by selective laser melting: a comparative analysis

Antanasova¹,

Kocjan²,

Žužek³

et al. 2019

Mater. Tehnol.

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This study was set up to explore the effects of the applied routes for fabricating cobalt-chromium (Co-Cr) dental frameworks on the metal-ceramic bond strength. Three groups (n = 12/group) of Co-Cr specimens (25×3×0.5) mm were fabricated by casting, milling, and by selective laser melting (SLM), and then airborne-particle abraded (110 μm Al2O3 particles). Dental porcelain was applied (8×3×1.1) mm onto the Co-Cr substrates, and the metal-ceramic bond strength was assessed by a three-point bend test according to the ISO 9693-1:2012 standard. Failure modes were determined using stereomicroscopy. Representative specimens from each group were used to assess the element distribution across the metal-ceramic interface, together with an inspection of its microstructure using a scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS). Average profile roughness (Ra) values were obtained for each group of metal substrates. The metal-ceramic bond strength data and Ra data were statistically analyzed (one-way ANOVA, Tukey's HSD test, a = 0.05). The mean surface roughness was affected by the fabrication technology (p < 0.01), SLM Co-Cr demonstrating a significantly higher Ra value (1.78±0.20 μm), than cast and milled Co-Cr (1.21±0.07 μm and 1.05±0.11 μm respectively). However, the metal processing applied did not affect the metal-ceramic bond (p = 0.104). Differently processed metal-ceramic specimens showed a comparable distribution of elements on the interface, together with good wetting between the alloy and the porcelain. The porcelain bond strengths to cast, milled and SLM Co-Cr alloys are well above the minimum ISO 9693-1:2012 recommended value of 25 MPa for metal-ceramic systems, thus allowing the clinical application of SLM Co-Cr in porcelain-fused-to-metal prostheses.

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Porcelain bonding to novel Co–Cr alloys: Influence of interfacial reactions on phase stability, plasticity and adhesion

Cited by 18 publications

References 26 publications

Comparative Analysis of Mechanical Properties and Metal-Ceramic Bond Strength of Co-Cr Dental Alloy Fabricated by Different Manufacturing Processes

Comparative Analysis of Mechanical Properties and Metal-Ceramic Bond Strength of Co-Cr Dental Alloy Fabricated by Different Manufacturing Processes

Application of a Novel CVD TiN Coating on a Biomedical Co–Cr Alloy: An Evaluation of Coating Layer and Substrate Characteristics

The bond strength of dental porcelain to cobalt-chromium alloys fabricated by casting, milling and by selective laser melting: a comparative analysis

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