| 1. |
- Barkarmo, Sargon, et al.
(författare)
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Biofilm formation on polyetheretherketone and titanium surfaces
- 2019
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Ingår i: Clinical and Experimental Dental Research. - : Wiley. - 2057-4347. ; 5:4, s. 427-437
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Polyetheretherketone (PEEK) is a polymer used in devices in orthopedic and dental rehabilitation. The aim of this in vitro study was to compare biofilm formation by a range of important oral bacterial species on PEEK, blasted PEEK, commercially pure titanium (cp-Ti), and titanium-6 aluminium-4 vanadium (Ti6Al4V). Material and methods: Coin-shaped samples were manufactured, and the surfaces were characterized using optical interferometry, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and contact angle measurements. Bacterial species of Streptococcus sanguinis, Streptococcus oralis, Enterococcus faecalis, and Streptococcus gordonii were cultured on the four material surfaces for varying amounts of time. Biofilms were quantified following staining with crystal violet. Results: Roughness and contact angle results showed blasted PEEK>PEEK>cp-Ti=Ti6Al4V. There was increased biofilm formation on blasted PEEK by S. sanguinis, S. oralis, and S. gordonii, whereas the bacterial adhesion was similar on PEEK, cp-Ti, and Ti6Al4V. The bacterial growth of E. faecalis was significantly higher on cp-Ti compared with the other three groups. Conclusion: The results, taking into consideration the biofilm formation, suggest that PEEK should perform as well as cp-Ti or TiAl6V4 when used as a dental restorative material. © 2019 The Authors. Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.
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| 2. |
- Barkarmo, Sargon, et al.
(författare)
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Inflammatory cytokine release from human peripheral blood mononuclear cells exposed to polyetheretherketone and titanium-6 aluminum-4 vanadium in vitro.
- 2018
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Ingår i: Journal of biomaterials applications. - : SAGE Publications. - 1530-8022 .- 0885-3282. ; 33:2, s. 245-258
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Tidskriftsartikel (refereegranskat)abstract
- Objective To investigate the cytokine expression profiles of blood cells exposed to polyetheretherketone and titanium-6 aluminum-4 vanadium materials in vitro. Materials and methods Coin-shaped samples composed of titanium-6 aluminum-4 vanadium, polyetheretherketone, and blasted polyetheretherketone were manufactured. The surfaces of the coins were characterized using optical interferometry, scanning electron microscopy, and contact angle measurements. Peripheral blood mononuclear cells collected from 10 blood donors were cultured for one, three, and six days in the presence or absence of the coins, and then assayed for cytokine production. Quantification of the peripheral blood mononuclear cells attached to the coins was performed using confocal microscopy after immunofluorescence staining. Results The machined titanium-6 aluminum-4 vanadium coins had a smoother surface topography compared to the machined polyetheretherketone and blasted polyetheretherketone. The highest mean contact angle was noted for the blasted polyetheretherketone, followed by the machined polyetheretherketone and titanium-6 aluminum-4 vanadium. The peripheral blood mononuclear cells produced significantly more proinflammatory cytokines when exposed to the polyetheretherketone surface compared to the titanium-6 aluminum-4 vanadium surface, while the blasted polyetheretherketone induced the highest level of proinflammatory cytokine release from the peripheral blood mononuclear cells. Significantly more cells attached to both polyetheretherketone surfaces, as compared to the titanium-6 aluminum-4 vanadium surface. Conclusion Polyetheretherketone induces a stronger inflammatory response from peripheral blood mononuclear cells than does titanium-6 aluminum-4 vanadium. Surface topography has an impact on cytokine release from peripheral blood mononuclear cells.
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| 3. |
- Franco Tabares, Sebastian, et al.
(författare)
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Chemical bonding to novel translucent zirconias: A mechanical and molecular investigation
- 2019
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Ingår i: Journal of Adhesive Dentistry. - 1757-9988 .- 1461-5185. ; 21:2, s. 107-116
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate direct bonding of a 10-MDP-based cement to two novel translucent yttria-stabilized tetragonal zirconia polycrystal ceramics (4Y-TZP, 5Y-TZP) and observe the influence of thermocycling on this bonding. Materials and Methods: Powders of presintered and isostatically pressed 5Y-TZP, 4Y-TZP and 3Y-TZP were mixed with a 10-MDP-based cement (Panavia F 2.0), then stored in deionized water for 48 h at 37°C or thermocycled 10,000 times. Raman spectroscopy and Fourier-transform infrared spectroscopy were used to assess the presence of a functional group (PO32-) that could indicate bonding before and after thermocycling. X-ray photoelectron spectroscopy was used to identify the presence of the suspected Zr-O-P bond in the same specimens. A shearbond strength (SBS) test was conducted based on ISO 29022:2013. Results: Marked peaks assigned to the asymmetric vibrations of the PO32- functional group were observed in both zirconias before and after thermocycling. The binding energy corresponding to Zr-O-P interactions (531.5 eV) was masked by the aluminosilicate in the filler of the cement. Shear bond strengths were approximately 20 MPa after water storage and approximately 6 MPa after thermocycling. No differences were found between the control group and the translucent zirconias. Conclusion: Direct bonding of the 10-MDP-based cement to both 4Y-TZP and 5Y-TZP was highly plausible. Both 4YTZP and 5Y-TZP may be promising alternatives to glass-ceramic restorations.
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| 4. |
- Franco Tabares, Sebastian, et al.
(författare)
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Effect of airborne-particle abrasion and polishing on novel translucent zirconias: Surface morphology, phase transformation and insights into bonding
- 2021
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Ingår i: Journal of Prosthodontic Research. - : Japan Prosthodontic Society. - 1883-1958 .- 2212-4632. ; 65:1, s. 97-105
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The purpose this study was to investigate the effect of Kern ' s air-borne particle abrasion protocol (KAPA) and polishing on two translucent zirconias (4Y, 5Y-zirconias) compared to a traditional zirconia (3Y-zirconia). Methods: Two different surface treatments were analysed by X-ray diffraction (XRD) and interferometry 1) KAPA (0.1 MPa, 50 mu m alumina, 10-12 mm distance, 15 sec and 30 sec and cleaning in ultrasound using isopropyl alcohol 99%) and 2) Clinical-delivery polishing paste (Zircon Brite, Dental Ventures, USA). Shear-bond strength tests (SBS's) were performed with a highly polished and virtually flat surface in combination with a 10-MDP based cement and a surface modified by KAPA in combination with zinc phosphate cement. The SBS was expressed in terms of MPa. Results: The mean values for monoclinic content were 13 wt%, 7 wt% and 2 wt% for 3Y-, 4Y- and 5Y-zirconias respectively, no differences were found between 15 and 30 seconds. Polishing did not result in phase transformation to monoclinic phase in any of the zirconias. The rhombohedral phase was identified in all types of zirconias regardless of surface treatment. Shear-bond strength tests showed 5 MPa for polished/10-MDP based cement and 3 MPa for KAPA/Zinc phosphate. Statistically significant differences were found between the two different surface treatments but not between the types of zirconias. Conclusions: KAPA for 15 sec seems to be equal to 30 sec regarding morphology and phase transformation. Sole micro-retention appears not to be fully responsible for the bonding phenomena of 10-MDP and zirconia that underwent KAPA.
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| 5. |
- Franco Tabares, Sebastian, et al.
(författare)
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Limited Effect of Cement Material on Stress Distribution of a Monolithic Translucent Zirconia Crown: A Three-Dimensional Finite Element Analysis.
- 2018
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Ingår i: The International journal of prosthodontics. - : Quintessence Publishing. - 0893-2174 .- 1139-9791. ; 31:1, s. 67-70
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Tidskriftsartikel (refereegranskat)abstract
- The literature shows that the performance of densely sintered zirconia single crowns seems to be unaffected by the cement material. The purpose of this study was to evaluate the effects of various cement materials on the stress distribution in a monolithic translucent zirconia crown.A crown-cement-dentin complex was modeled. Six cements were evaluated: zinc phosphate, glass-ionomer, resin-modified glass-ionomer, dual-cure resin, calcium aluminate-based, and a theoretical or conceptual cement with mechanical properties close to those of dentin (ie, monoblock cement).While varying stress concentrations were found within the cements, the stress concentrations in the crown and dentin were consistent irrespective of cement material.Within the limitations of this study, it can be concluded that cement material had a negligible effect on stress distribution in the monolithic zirconia crown.
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| 6. |
- Franco Tabares, Sebastian
(författare)
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On translucent yttria stabilized zirconia ceramics: Mechanical considerations, phase transformation and cement choices
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- New zirconia formulations (4Y and 5Y-zirconias) have been introduced for prosthodontic therapy and are commercialized as “translucent” zirconias. No clinical information providing their survival rates or complications has been provided to the date. This has investigated thesis aimed to investigate different variables regarding some of their mechanical aspects, crystallographic and morphological characterization and alternatives for their cementation. A finite element analysis was performed in order to observe the stress distribution on a monolithic translucent zirconia crown when cemented with different cements. The bonding potential of a 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP)-based commercial cement to two translucent zirconias was assessed using Raman spectroscopy (RS), Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). A shear bond strength test was complementary to these analytical methods. The crystallographic structure and surface morphology of two translucent zirconias was estimated by X-ray diffraction (XRD) and interferometry after airborne-particle abrasion (APA) and polishing. The effect of the cement and air-borne particle abrasion and on the fracture strength of monolithic 4Y-zirconia crowns were also evaluated. And lastly, fracture toughness and hardness were estimated by Vickers hardness measurements. The stress distribution on a monolithic translucent zirconia crown seems to be unaffected by the cement material. Bonding to 4Y and 5Y-zirconias seems plausible by using a 10-MDP-based cement, nonetheless, thermocycling seems to reduce the bond's strength. The APA protocol produced monoclinic zirconia and was inversely related to the yttria content. Polishing did not cause any monoclinic zirconia. The surface area and surface roughness were increased after the APA protocol. The fracture strength of the monolithic 4Y-zirconias was unaffected by the APA protocol and the cement choice. Differences in fracture toughness and hardness were observed. Within the limitations of the studies presented in this thesis, it could be summarized that the translucent zirconias differentiate themselves from the traditional formulations, specially 5Y-zirconias in fracture toughness. Special caution is recommended in their clinical use. Nevertheless, bonding seems possible via a 10-MDP based cement.
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| 7. |
- Johansson, Camilla, et al.
(författare)
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Laboratory, Clinical-Related Processing and Time-Related Factors’ Effect on Properties of High Translucent Zirconium Dioxide Ceramics Intended for Monolithic Restorations A Systematic Review
- 2023
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Ingår i: Ceramics. - : MDPI. - 2571-6131. ; 6:1, s. 734-797
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Forskningsöversikt (refereegranskat)abstract
- Because new zirconia materials are constantly being developed, the aim was to identify and qualitatively synthesize research on how processing and time-related factors affect the properties of high translucent (HT) zirconia intended for monolithic restorations. Cochrane Library, PubMed, Scopus, Web of Science, and reference lists were searched for in vitro and clinical studies. Eligibility and risk of bias were assessed. A synthesis of 142 publications was performed. HT 3Y-TZP was the most common, followed by 5YSZ, 4YSZ, and multilayer. In the laboratory, HT 3Y-TZP should be sintered according to the manufacturer’s recommendation and polished before glazing to favour strength, roughness, and wear behaviour. In the clinic, polishing is necessary after grinding to favour roughness and aging resistance. Over time, when using hydrothermal aging, t–m phase transformation and reduced translucency are expected, without affecting the strength and roughness. The strength of 4YSZ and 5YSZ is unaffected. However, the time-related methods are of questionable clinical significance. The evidence of all other factors’ effects on the properties of HT zirconia is lacking or limited; thus, these factors are of relevance for future research. There is a high heterogeneity of study designs and methods, and the results are brand-dependent.
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