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Mayinger F, Ender A, Strickstrock M, Elsayed A, Nassary Zadeh P, Zimmermann M, Stawarczyk B. Impact of the sintering parameters on the grain size, crystal phases, translucency, biaxial flexural strength, and fracture load of zirconia materials. J Mech Behav Biomed Mater 2024; 155:106580. [PMID: 38759588 DOI: 10.1016/j.jmbbm.2024.106580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 05/06/2024] [Accepted: 05/10/2024] [Indexed: 05/19/2024]
Abstract
OBJECTIVES To investigate the influence of the zirconia and sintering parameters on the optical and mechanical properties. METHODS Three zirconia materials (3/4Y-TZP, 4Y-TZP, 3Y-TZP) were high-speed (HSS), speed (SS) or conventionally (CS) sintered. Disc-shaped specimens nested in 4 vertical layers of the blank were examined for grain size (GS), crystal phases (c/t'/t/m-phase), translucency (T), and biaxial flexural strength. Fracture load (FL) of three-unit fixed dental prostheses was determined initially and after thermomechanical aging. Fracture types were classified, and data statistically analyzed. RESULTS 4Y-TZP showed a higher amount of c + t'-phase and lower amount of t-phase, and higher optical and lower mechanical properties than 3Y-TZP. In all materials, T declined from Layer 1 to 4. 3/4Y-TZP showed the highest FL, followed by 3Y-TZP, while 4Y-TZP showed the lowest. In 4Y-TZP, the sintering parameters exercised a direct impact on GS and T, while mechanical properties were largely unaffected. The sintering parameters showed a varying influence on 3Y-TZP. Thermomechanical aging resulted in comparable or higher FL. CONCLUSION 3/4Y-TZP presenting the highest FL underscores the principle of using strength-gradient multi-layer blanks to profit from high optical properties in the incisal area, while ensuring high mechanical properties in the lower areas subject to tensile forces. With all groups exceeding maximum bite forces, the examined three-unit FDPs showed promising long-term mechanical properties.
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Affiliation(s)
- Felicitas Mayinger
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Goethestraße 70, 80336, Munich, Germany.
| | - Andreas Ender
- Division of Computerized Restorative Dentistry, Clinic of Conservative and Preventive Dentistry, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland
| | - Monika Strickstrock
- Faculty of Engineering and Computer Science, Material Science and Analysis, University of Applied Sciences Osnabrück, Albrechtstraße 30, 49076, Osnabrück, Germany
| | - Adham Elsayed
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Goethestraße 70, 80336, Munich, Germany
| | - Parissa Nassary Zadeh
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Goethestraße 70, 80336, Munich, Germany
| | - Marcus Zimmermann
- Division of Computerized Restorative Dentistry, Clinic of Conservative and Preventive Dentistry, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland
| | - Bogna Stawarczyk
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Goethestraße 70, 80336, Munich, Germany
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Cesar PF, Miranda RBDP, Santos KF, Scherrer SS, Zhang Y. Recent advances in dental zirconia: 15 years of material and processing evolution. Dent Mater 2024; 40:824-836. [PMID: 38521694 PMCID: PMC11098698 DOI: 10.1016/j.dental.2024.02.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/25/2024]
Abstract
OBJECTIVES The objective was to discuss the research on zirconia published in the past 15 years to help the dental materials community understand the key properties of the types of zirconia and their clinical applications. METHODS A literature search was performed in May/2023 using Web of Science Core Collection with the term "dental zirconia". The search returned 5102 articles, which were categorized into 31 groups according to the research topic. RESULTS The current approach to improving the translucency of zirconia is to decrease the alumina content while increasing the yttria content. The resulting materials (4Y-, 5Y-, and above 5 mol% PSZs) may contain more than 50% of cubic phase, with a decrease in mechanical properties. The market trend for zirconia is the production of CAD/CAM disks containing more fracture resistant 3Y-TZP at the bottom layers and more translucent 5Y-PSZ at the top. Although flaws located between layers in multilayered blocks might represent a problem, newer generations of zirconia layered blocks appear to have solved this problem with novel powder compaction technology. Significant advancements in zirconia processing technologies have been made, but there is still plenty of room for improvement, especially in the fields of high-speed sintering and additive manufacturing. SIGNIFICANCE The wide range of zirconia materials currently available in the market may cause confusion in materials selection. It is therefore imperative for dental clinicians and laboratory technicians to get the needed knowledge on zirconia material science, to follow manufacturers' instructions, and to optimize the design of the prosthetic restoration with a good understanding where to reinforce the structure with a tough and strong zirconia.
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Affiliation(s)
- Paulo Francisco Cesar
- Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, São Paulo, Brazil.
| | | | - Karina Felix Santos
- Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Susanne S Scherrer
- Division of Fixed Prosthodontics and Biomaterials, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland
| | - Yu Zhang
- Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, USA
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Chen Z, Zhang M, Zhang R, Hao P. Effect of the coloring liquid shade and dipping time on the color, transparency, and flexural strength of monolithic zirconia. J Prosthet Dent 2024:S0022-3913(24)00228-2. [PMID: 38604904 DOI: 10.1016/j.prosdent.2024.03.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 04/13/2024]
Abstract
STATEMENT OF PROBLEM The impact of different coloring liquid shades and dipping times on the color, transparency, and flexural strength of monolithic zirconia ceramics is unclear. PURPOSE The purpose of this in vitro study was to evaluate the effects of different coloring liquid shades (A2, 3M2, and 5M2) and dipping times (no dipping, 30 seconds, 60 seconds, and 90 seconds) on the color difference (ΔE00), relative translucency parameter (ΔRTP00), and 3-point flexural strength (σ) of monolithic zirconia ceramics. MATERIAL AND METHODS Yttria-stabilized zirconia (3Y-TZP, 3 mol%) was cut into Ø16×1.2-mm plates (n=10) and 25×4×1.2-mm bars (n=15), which were colored using 3 shades of coloring liquid at 4 dipping times. Color coordinates were measured on a gray background by using a digital spectrophotometer with an integrating sphere attachment. The color and translucency differences were evaluated using 50:50% perceptibility (PT00 and TPT00) and acceptability (AT00 and TAT00) thresholds. The 3-point flexural strengths of the bar-shaped specimens were measured using a universal testing machine and analyzed using the Weibull distribution to calculate the Weibull modulus (m) and characteristic fracture strength (σ0). The data were analyzed with the 2-way ANOVA, Kruskal-Wallis, and LSD post hoc tests (α=.05). RESULTS Both shade and dipping time significantly affected the color and translucency of monolithic zirconia (P<.001). The ΔE00 was above the PT00 for all groups, with only 3M2-90 and A2-60 being below the AT00. The main cause of color differences was the difference in lightness. Only A2 showed ΔRTP00 below the TPT00 (A2-30 (ΔRTP00=0.26), A2-60 (ΔRTP00=0.29), and A2-90 (ΔRTP00=0.46)). All experimental groups showed translucency differences below TAT00. In addition, only the dipping time had a significant effect on the flexural strength of zirconia (P<.001). CONCLUSIONS The optical properties of monolithic zirconia ceramics were affected by the shade and dipping time of the coloring liquid. The mismatch in lightness was the main reason for the color difference. The dipping time affects the flexural strength of monolithic zirconia, whereas the shade of the coloring liquid did not seem to influence flexural strength.
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Affiliation(s)
- Zijie Chen
- Graduate student, Dental Technology, School of Stomatology, Binzhou Medical University, Yantai, PR China
| | - Mengmeng Zhang
- Graduate student, Dental Technology, School of Stomatology, Binzhou Medical University, Yantai, PR China
| | - Rimei Zhang
- Graduate student, Yantai Stomatological Hospital of Binzhou Medical University, Yantai, PR China
| | - Pengjie Hao
- Associate Professor, Department of Prosthodontics, Yantai Stomatological Hospital of Binzhou Medical University, Yantai, PR China.
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Bakitian F. Flexural Strength of Translucent Zirconia Materials Produced with Different Multilayer Technologies: An In Vitro Study. Int J Dent 2024; 2024:8410101. [PMID: 38571767 PMCID: PMC10990640 DOI: 10.1155/2024/8410101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/08/2024] [Accepted: 03/10/2024] [Indexed: 04/05/2024] Open
Abstract
Objective To evaluate the flexural strength of two translucent multilayered zirconia materials produced with different multilayer technologies. Methodology. Eighty bar-shaped zirconia specimens were prepared from two different multilayered zirconia materials (IPS e.max® ZirCAD Prime and KATANA™ Multilayered Zirconia HTML) and divided into eight groups (n = 10) based on the materials used and the individual layers of the disc for each material: Dentin Prime, Transition Prime, Translucent Prime, Multilayered Prime, Dentin HTML, Transition HTML, Translucent HTML, and Multilayered HTML. The bar-shaped zirconia specimens were cut to include all the layers from translucent to dentin In Multilayered Prime and Multilayered HTML groups. All specimens were fully sintered after cutting from multilayered zirconia discs and subjected to three-point flexural strength test using the universal testing machine. Results The specimens made of HTML zirconia material showed significantly (P < 0.001) higher flexural strength than those made of IPS e.max® ZirCAD Prime material, with no significant difference (P > 0.05) compared to the specimens in the Dentin Prime group. The Dentin Prime specimens had the highest flexural strength (743 ± 116 MPa) compared to those in the Translucent Prime (514 ± 120 MPa), Transition Prime (575 ± 102 MPa), and Multilayered Prime (531 ± 132 MPa) groups. The flexural strength of the specimens from the individual layers of HTML zirconia material was not significantly different (P > 0.05) among the Dentin HTML (763 ± 56 MPa), Translucent HTML (791 ± 106 MPa), Transition HTML (816 ± 85 MPa), and Multilayered HTML (793 ± 102 MPa) groups. Conclusion Multilayered zirconia materials produced with different yttria contents by layer have lower flexural strength than those produced with gradient shade technology and the same yttria content for each layer. Therefore, various factors such as the type of prostheses, nesting strategies of prostheses within the zirconia disc, and the desired aesthetical requirements should be considered when selecting the multilayered zirconia materials.
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Affiliation(s)
- Fahad Bakitian
- Department of Restorative Dentistry, Faculty of Dental Medicine, Umm Al-Qura University, Makkah, Saudi Arabia
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Albakri IA, AlHorani Z, Hatamleh M, Al-Omari WM. Evaluation of Shade Reproducibility and Mechanical Properties of Preshaded and Manually Shaded Monolithic Zirconia. Oper Dent 2024; 49:110-116. [PMID: 38180471 DOI: 10.2341/23-016-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2023] [Indexed: 01/06/2024]
Abstract
OBJECTIVES This study aimed to investigate the effect of manual coloring of blank monolithic zirconia blocks of four materials on their shade reproducibility, flexural strength, and surface roughness as compared with preshaded blocks of the same material. METHODS AND MATERIALS Eight disc-shaped specimens (diameter=12mm; height=2mm) and eight bar-shaped specimens (25×2×2 mm) were milled from the shaded and non-shaded blocks of the four zirconia systems: Ceramill, Kerox, White Peaks, and Dental Direkt. In total, 128 specimens were fabricated. The non-shaded specimens of each system were coloured according to A2 shade. The surface roughness (Ra) was measured using a contact profilometer. Color difference was calculated according to the CIEDE2000 formula. The bar-shaped specimens were loaded to fracture following three-point bend testing at 1 mm/minute crosshead speed. Data were analysed following one-way analysis of variance (ANOVA), and the Tukey post-hoc test (p=0.05). RESULTS Manual-coloring affected the surface roughness, color difference, and flexural strength of three materials in comparison to their preshaded blocks (p<0.05). White Peaks was not affected (p>0.05). Ra values ranged from 1.1-1.9; three materials were not affected (p>0.05). Kerox preshaded blocks were the smoothest (p<0.05) but became the roughest once colored (p<0.05). White Peaks and Dental Direkt materials had preshaded blocks matching the A2 guide-tab (p>0.05). DE was perceptible and unacceptable for the preshaded and manually shaded blocks of all materials tested (ΔE>1.8). While manual coloring reduced flexural strength of Ceramill and Dental Direkt (p<0.05), flexural strength was retained by Kerox and White Peaks (p>0.05). CONCLUSIONS White Peaks was not affected by the coloring technique. Coloring had negative effects on Ceramill flexural strength and color reproducibility.
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Affiliation(s)
- I A Albakri
- *Isra' Abdelkarim Moh'd Albakri, MPhiL, PhD, assistant professor, Department of Applied Dental Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid-Jordan
| | - Z AlHorani
- Zaid AlHourani, PhD, associate professor, Department of Applied Dental Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid-Jordan
| | - M Hatamleh
- Muhanad Hatamleh, PhD, professor, Department of Applied Dental Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid-Jordan
| | - W M Al-Omari
- Wael M Al-Omari, PhD, professor, Department of Prosthodontics, Faculty of Dentistry, Jordan University of Science and Technology, Irbid-Jordan
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Yousry MA, Hammad IA, El Halawani MT, Aboushelib MN. Effect of sintering time on microstructure and optical properties of yttria-partially stabilized monolithic zirconia. Dent Mater 2023; 39:1169-1179. [PMID: 37845165 DOI: 10.1016/j.dental.2023.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 09/12/2023] [Accepted: 10/05/2023] [Indexed: 10/18/2023]
Abstract
OBJECTIVES To evaluate the impact of speed sintering on the microstructure and optical properties of 3 and 5 mol% yttria-partially stabilized monolithic zirconias. METHODS 120 plate-shaped zirconia specimens (10x10x 0.4 mm) were prepared from three commercial 5 mol% yttria-partially stabilized zirconia blocks (5Y-PSZs); Katana UTML (Kuraray Noritake), Cercon xtML (Dentsply Sirona), and Zolid FX white (Amann Girrbach), and two commercial 3 mol% yttria-partially stabilized zirconia blocks (3Y-PSZs); Lava Plus (3 M ESPE) and InCoris (Sirona, GmbH). Specimens were either conventional sintered (CS) using a 7-hour program or speed sintered (SS) using a quick 90-minute program. The microstructure was inspected with a scanning electron microscope (SEM), and phase fractions were detected using x-ray diffraction analysis (XRD). Translucency (TP00), and contrast ratio (CR) were obtained using a spectrophotometer (VITA Easyshade V). Color difference (ΔE00) between both sintering processes was calculated with the CIEDE2000 formula. ΔE00 up to 1.8 was set as the acceptability threshold. Data were analyzed using two-way ANOVA, Krusakll-Wallis, and Mann-Whitney U tests. (n = 12, α = .05). RESULTS Grain size was significantly decreased after SS for all tested materials (P < .0001). The average grain sizes of 5Y-PSZs were significantly larger than those of 3Y-PSZs. The atomic structure, microstructure, and transparency of CS and SS were all affected by the amount of yttria, the size of the crystals, and tetragonality. SS significantly reduced TP00 (F = 7135.95, P < 0.0001) and increased CR (F = 453.21, P < 0.0001). The CS Katana presented the highest TP00 and lowest CR value. ΔE00 between the CS and SS groups were clinically acceptable except for Lava, which had values above the set threshold (1.89). SIGNIFICANCE SS altered the grain size and internal structure of the tested materials, which was reflected in translucency.
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Affiliation(s)
- Mahinour A Yousry
- Division of Fixed Prosthodontics, Department of Conservative Dentistry, Faculty of Dentistry, Alexandria University, Alexandria, Egypt.
| | - Ihab A Hammad
- Division of Fixed Prosthodontics, Department of Conservative Dentistry, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - Mohamed T El Halawani
- Division of Fixed Prosthodontics, Department of Conservative Dentistry, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - Moustafa N Aboushelib
- Department of Dental Materials Science, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
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Souza LFB, Soares PM, Ribeiro VF, Scotti N, Kleverlaan CJ, Bacchi A, Pereira GKR. Influence of coloring techniques on the surface characteristics and color stability of a monolithic zirconia ceramic. J Prosthet Dent 2023; 130:392.e1-392.e9. [PMID: 37516645 DOI: 10.1016/j.prosdent.2023.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 07/31/2023]
Abstract
STATEMENT OF PROBLEM The color of monolithic zirconia restorations is obtained by presintering or postsintering coloring techniques. However, studies on the differences in surface characteristics and their influence on color stability are lacking. PURPOSE The purpose of this in vitro study was to evaluate the influence of shading and staining techniques for a zirconia ceramic on the surface characteristics and colorimetric parameters (color difference, translucency, and whiteness index) after exposure to coffee or red wine and then polishing. MATERIAL AND METHODS Ceramic disks (N=30; Ø10×1mm) were allocated into 3 groups: preshaded-shaded by the manufacturer (IPS e.max ZirCAD MT, shade A2); manually shaded-unshaded zirconia (IPS e.max ZirCAD MT, bleaching shade-BL) colored by the brushing technique, before sintering; stained-unshaded zirconia (IPS e.max ZirCAD MT BL) colored by the staining technique, after sintering. Spectrophotometric color assessments ensured the same initial perceived color (Vita Classical A2) for specimens included in the study (∆E00<1.77 acceptability threshold). Surface characteristics were assessed by scanning electron microscopy and atomic force microscopy. The specimens were immersed in coffee (n=5) or red wine (n=5) for 12 and 24 days and subsequently polished. The data were statistically and descriptively analyzed for color differences (∆E00), translucency parameters (TP00), and whiteness indexes for dentistry (WID), considering acceptability and perceptibility thresholds. RESULTS The shaded groups found an irregular ceramic surface with uniformly sized zirconia crystals. The stained group found a glass-covered smoother surface. Significant alterations in color parameters (∆E00, TP00, WID) were observed with immersion in pigmenting beverages (P<.001) both after 12 days, and after 24 days. The shaded specimens had greater color alterations after immersion but benefited from the polishing procedure, which reduced color differences below an acceptable threshold in comparison with the baseline. Stained specimens had lower color alterations after immersion, but the polishing protocol was detrimental as it whitened the ceramic by subsurface exposure. CONCLUSIONS The coloring technique influences the surface characteristics of zirconia ceramic and also the color parameters after exposure to colored beverages and polishing.
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Affiliation(s)
- Luiza Freitas Brum Souza
- Postgraduate Program in Oral Sciences (Prosthodontics Units), Faculty of Odontology, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil
| | - Pablo Machado Soares
- Postgraduate Program in Oral Sciences (Prosthodontics Units), Faculty of Odontology, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil
| | - Vinícius Fogliato Ribeiro
- Undergraduate student, Department of Restorative Dentistry, Postgraduate Program in Oral Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil
| | - Nicola Scotti
- Department of Surgical Sciences, Dental School, University of Turin, Turin, Italy
| | - Cornelis Johannes Kleverlaan
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, Noord-Holland, the Netherlands
| | - Ataís Bacchi
- Postgraduate Program in Dentistry, Paulo Picanço School of Dentistry, Fortaleza, CE, Brazil
| | - Gabriel Kalil Rocha Pereira
- Undergraduate student, Department of Restorative Dentistry, Postgraduate Program in Oral Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
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Dolve E, Ben-Izhack G, Meirowitz A, Erel H, Rosner O, Biadsee A, Lugassy D, Shely A. The Light Reflection Changes of Monolithic Zirconia and Lithium Disilicate after Using Two External Staining Kits following by Thermocycling. MATERIALS (BASEL, SWITZERLAND) 2023; 16:2057. [PMID: 36903172 PMCID: PMC10004587 DOI: 10.3390/ma16052057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND The purpose of the study was to evaluate the changes of light reflection% on two materials (monolithic zirconia and lithium disilicate) after using two external staining kits following by thermocycling. METHODS Specimens were sectioned from monolithic zirconia (n = 60) and lithium disilicate (n = 60) then divided into six groups (n = 20). Two different types of external staining kits were used and applied to the specimens. The light reflection% was measured before staining, after staining and after thermocycling using a spectrophotometer. RESULTS The light reflection% of zirconia was significantly higher compared to lithium disilicate at the beginning of the study (p = 0.005), after staining with kit 1 (p = 0.005) and kit 2 (p = 0.005) and after thermocycling (p = 0.005). For both materials, the light reflection% was lower after staining with Kit 1 compared to kit 2 (p < 0.043). After thermocycling, the light reflection% of lithium disilicate increased (p = 0.027) and was unchanged with Zirconia (p = 0.527). CONCLUSIONS There is a difference between the materials regarding light reflection% as the monolithic zirconia showed higher light reflection% comparing lithium disilicate throughout the entire experiment. For lithium disilicate, we recommend using kit 1 as we found that, after thermocycling, the light reflection% of kit 2 was increased.
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Toma FR, Porojan SD, Vasiliu RD, Porojan L. The Effect of Polishing, Glazing, and Aging on Optical Characteristics of Multi-Layered Dental Zirconia with Different Degrees of Translucency. J Funct Biomater 2023; 14:jfb14020068. [PMID: 36826868 PMCID: PMC9967825 DOI: 10.3390/jfb14020068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/14/2023] [Accepted: 01/24/2023] [Indexed: 02/01/2023] Open
Abstract
(1) Background: Considering that the appearance of a dental material is an important factor that contributes to the success of prosthetic restorations. The purpose of this study is to investigate the optical properties and color changes among the layers of three commercial zirconias, to compare the aspect of the polished and glazed surfaces before and after aging and to evaluate the effects of hydrothermal degradation on their aesthetics. (2) Methods: Forty-eight plate-shaped samples were sectioned from presintered blocks of each multilayer translucent zirconia with different Yttrium content: Ceramill Zolid fx ML (5 mol%) = CeZ, STML (4 mol%) = STM, IPS e.maxZirCAD CEREC/in Lab MT Multi (4 mol% + 5 mol%) = IPZ. The samples were sintered according to the recommendation of each manufacturer, and half (24) of them were polished and the other half (24) glazed on one of the surfaces. Each type was equally divided into one control and one aging group, and, for each material, this resulted in four groups (n = 12): polished-control, polished-autoclaved glazed-control, and glazed-autoclaved. The artificial aging was carried out with an autoclave and distilled water at 134 °C, 0.2 MPa for 1 h, and for optical parameters (TP, CR, OP) and color change (ΔE*) measurements on a black and white background in a CIE L*a*b* color system, a spectrophotometer was used. The specimens were evaluated in incisal, cervical, and medium areas on polished and glazed samples before and after the aging stage. Statistical analysis was achieved with a two-way ANOVA test, the unpaired t-test, and the paired t-test. (3) Results: Before and after aging, the mean TP values for polished samples were higher than the glazed ones. After aging, the mean TP values increased for all groups (except polished CeZ), and significant differences were reported for polished STM, IPZ. After LTD, the opalescence registered an increase for almost all groups (except polished CeZ, polished and glazed IPZ-medium area), and significant differences were reported for almost all groups (except STM-incisal, IPZ-cervical, medium areas). The levels of color change were between extremely slight to perceivable. (4) Conclusions: Optical properties of the selected multilayer zirconia were influenced by polishing and glazing as surface treatment and affected by artificial aging (CeZ the least); perceivable color changes for polished STM, IPZ were detected.
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Affiliation(s)
- Flavia Roxana Toma
- Department of Dental Prostheses Technology (Dental Technology), Center for Advanced Technologies in Dental Prosthodontics, Faculty of Dental Medicine, “Victor Babeș” University of Medicine and Pharmacy Timișoara, Eftimie Murgu Sq. No. 2, 300041 Timisoara, Romania
| | - Sorin Daniel Porojan
- Department of Oral Rehabilitation (Dental Technology), Center for Advanced Technologies in Dental Prosthodontics, Faculty of Dental Medicine, “Victor Babeș” University of Medicine and Pharmacy Timișoara, Eftimie Murgu Sq. No. 2, 300041 Timisoara, Romania
| | - Roxana Diana Vasiliu
- Department of Dental Prostheses Technology (Dental Technology), Center for Advanced Technologies in Dental Prosthodontics, Faculty of Dental Medicine, “Victor Babeș” University of Medicine and Pharmacy Timișoara, Eftimie Murgu Sq. No. 2, 300041 Timisoara, Romania
| | - Liliana Porojan
- Department of Dental Prostheses Technology (Dental Technology), Center for Advanced Technologies in Dental Prosthodontics, Faculty of Dental Medicine, “Victor Babeș” University of Medicine and Pharmacy Timișoara, Eftimie Murgu Sq. No. 2, 300041 Timisoara, Romania
- Correspondence:
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Souza LFB, da Rosa LS, Menna Barreto VS, Ribeiro VF, Fraga S, Kleverlaan CJ, Valandro LF, Pereira GKR. Pigmentation techniques of a 4YSZ: Effect on the fatigue mechanical behavior of a 4YSZ adhesively luted onto dentin analog. Dent Mater 2022; 38:2003-2013. [DOI: 10.1016/j.dental.2022.11.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 11/04/2022] [Accepted: 11/11/2022] [Indexed: 11/23/2022]
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da Silva AO, Fiorin L, Faria ACL, Ribeiro RF, Rodrigues RCS. Translucency and mechanical behavior of partially stabilized monolithic zirconia after staining, finishing procedures and artificial aging. Sci Rep 2022; 12:16094. [PMID: 36167885 PMCID: PMC9515067 DOI: 10.1038/s41598-022-20120-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 09/08/2022] [Indexed: 11/09/2022] Open
Abstract
Partially stabilized zirconia (5Y-PSZ) has been widely used to manufacture indirect monolithic restorations, and the effect of finishing procedures on the optical and mechanical properties of these materials are still unclear. The purpose of this study was to evaluate the effect of staining, polishing and glazing on surface roughness, crystalline phase content, microhardness, fracture toughness, dynamic elastic modulus, three-point flexural strength, strain distribution, color (∆E00/∆L/∆a/∆b), and translucency before and after artificial accelerated aging (water spray and ultraviolet) of 5Y-PSZ. Bar-shaped and rectangle-shaped specimens of the 5Y-PSZ were prepared and divided into six groups, according to finishing procedure: GC (control), GS (staining), GG (glazing), GSG (staining and glazing), GP (polishing), GSP (staining and polishing). There was a significant difference between groups for surface roughness (p < 0.05), dynamic elastic modulus (p = 0.007), microhardness (p = < 0.05), ∆E00 (p = 0.010), and ∆a (p = 0.008). GC presented higher cubic phase content, and the stained groups (GS, GSG and GSP) presented higher monoclinic content. The different finishing procedures affected roughness, dynamic elastic modulus, microhardness, and color of 5Y-PSZ; polishing being the finish that provides minors changes to the 5Y- PSZ. Accelerated artificial aging caused color change, regardless of finishing procedure used.
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Affiliation(s)
- Allan Oliveira da Silva
- Department of Dental Materials and Prosthesis, School of Dentistry of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Lívia Fiorin
- Department of Dental Materials and Prosthesis, School of Dentistry of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Adriana Claudia Lapria Faria
- Department of Dental Materials and Prosthesis, School of Dentistry of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Ricardo Faria Ribeiro
- Department of Dental Materials and Prosthesis, School of Dentistry of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Renata Cristina Silveira Rodrigues
- Department of Dental Materials and Prosthesis, School of Dentistry of Ribeirão Preto, University of São Paulo (USP), Av. do Café, s/n, Ribeirão Preto, SP, 14040-904, Brazil.
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Machry RV, Dapieve KS, Cadore-Rodrigues AC, Werner A, de Jager N, Pereira GKR, Valandro LF, Kleverlaan CJ. Mechanical characterization of a multi-layered zirconia: Flexural strength, hardness, and fracture toughness of the different layers. J Mech Behav Biomed Mater 2022; 135:105455. [PMID: 36148725 DOI: 10.1016/j.jmbbm.2022.105455] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/30/2022] [Accepted: 09/06/2022] [Indexed: 10/31/2022]
Abstract
This study compared the flexural strength under monotonic (static - sσ) and cyclic load application (fatigue - fσ), hardness (H) and fracture toughness (KIC) of different layers of a multi-layered zirconia (IPS e.max ZirCAD MT Multi, Ivoclar). Each layer was sectioned, classified into three groups according to yttria content (4-YSZ, 4/5-YSZ and 5-YSZ), and shaped on samples for flexural strength and fracture toughness tests (bars: 1.0 × 1.0 × 11 mm); and Vickers hardness test (plates: 1.5 × 4.0 × 5.0 mm). Flexural strength under monotonic load application (sσ; n = 10) was obtained through two different devices (three-point-bending and ball-in-hole device) and fatigue flexural strength (fσ; n = 15; initial load: 10 N; step-size: 5 N; 10,000 cycles/step) was assessed using a ball-in-hole device under cyclic load application. Vickers hardness test (n = 5), fracture toughness test (n = 10), and additional analyzes (Finite Element Analysis - FEA, Energy-dispersive X-ray spectroscopy - EDS and Scanning Electron Microscopy - SEM) were also performed. No differences were found between the different devices in the monotonic flexural strength test, and FEA showed similar tensile stress distribution for the two devices. 4-YSZ showed higher values of flexural strength under monotonic and cyclic load application modes (sσ = 1114.73 MPa; fσ = 798.84 MPa), and fracture toughness (KIC = 3.90 MPa√m). 4/5-YSZ had an intermediate sσ; however, fσ was similar to 5-YSZ (404.00-429.36 MPa) and KIC similar to 4-YSZ (KIC = 3.66 MPa√m). No statistical differences were found for hardness and Weibull modulus for fatigue flexural strength data. The amount of yttria in the layer compositions increased from 4-YSZ to 5-YSZ, and larger zirconia crystals were observed in the topographic images of 5-YSZ. Failures in the flexural strength and toughness tests started from the face subjected to tensile stress. Different layers of the multi-layered zirconia blank presented distinct mechanical properties. 4-YSZ (cervical layer) presented the highest flexural strength under monotonic and cyclic loads (fatigue), and higher fracture toughness even similar to the transition layer (4/5-YSZ). Hardness was similar between the layers. The ball-in-hole device performed similarly to the three-point bending device and can be used as an alternative to the traditional method.
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Affiliation(s)
- Renan Vaz Machry
- MSciD-PhD Post-Graduate Program in Oral Science, Faculty of Odontology, Federal University of Santa Maria, 1000 Roraima Av., Santa Maria, Rio Grande do Sul, Brazil.
| | - Kiara Serafini Dapieve
- MSciD-PhD Post-Graduate Program in Oral Science, Faculty of Odontology, Federal University of Santa Maria, 1000 Roraima Av., Santa Maria, Rio Grande do Sul, Brazil.
| | - Ana Carolina Cadore-Rodrigues
- MSciD-PhD Post-Graduate Program in Oral Science, Faculty of Odontology, Federal University of Santa Maria, 1000 Roraima Av., Santa Maria, Rio Grande do Sul, Brazil.
| | - Arie Werner
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, Noord-Holland, Netherlands.
| | - Niek de Jager
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, Noord-Holland, Netherlands.
| | - Gabriel Kalil Rocha Pereira
- MSciD-PhD Post-Graduate Program in Oral Science, Faculty of Odontology, Federal University of Santa Maria, 1000 Roraima Av., Santa Maria, Rio Grande do Sul, Brazil.
| | - Luiz Felipe Valandro
- MSciD-PhD Post-Graduate Program in Oral Science, Faculty of Odontology, Federal University of Santa Maria, 1000 Roraima Av., Santa Maria, Rio Grande do Sul, Brazil.
| | - Cornelis Johannes Kleverlaan
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, Noord-Holland, Netherlands.
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Altan B, Cinar S. Effect of Repeated Firings and Thickness on Optical Properties of Variable Preshaded and Shaded Novel Translucent Zirconia Blocks. BIOMED RESEARCH INTERNATIONAL 2022; 2022:8572782. [PMID: 36017380 PMCID: PMC9398792 DOI: 10.1155/2022/8572782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/05/2022] [Indexed: 11/18/2022]
Abstract
Objective The purpose of this study was to examine the optical properties of translucent zirconia with different thickness during multiple firings. Materials and Methods Three different types of translucent zirconia (Vita YZ HT (HT), Vita YZ ST (ST), Vita YZ XT (XT)) with thickness of 0.5, 1, and 1.5 mm were used in the study. 180 disk-shaped specimens (n = 10) were prepared from preshaded and nonshaded blocks. The coloring liquid (A2, Vita Shade Liquid) was applied with a synthetic nylon brush in the nonshaded group. Then, the specimens were then subjected to 1, 3, and 5 firing times. After consecutive firings, color differences (ΔE) and translucency parameter (TP) were measured. Statistical analysis was carried out by using repeated measure ANOVA followed by Tukey test. Results ANOVA analysis reveals that TP and ΔE were significantly affected by the repeated firings. The highest TP was seen in 0.5 mm XT specimen. For all specimens, TP decreases from 1st to 3rd firing cycles, despite TP increases from 3rd to 5th firing cycles. Although there is a significant change in TP values in 0.5 mm thickness, there is no significant change between firing cycles for 1 and 1.5 mm thickness specimens. The highest ΔE value was observed for shaded specimens between 1st and 5th firings. ΔE values were not significantly different between 1 and 3 firings. Conclusions Changes in thickness and repeated firings of zirconia specimens affected final color and translucency of zirconia specimens. HT blocks are more affected by consecutive firings than ST and XT blocks. ΔE increased as the thicknesses decreased for both types of translucent zirconia specimens tested.
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Affiliation(s)
- Bike Altan
- Department of Prosthodontics, Faculty of Dentistry, University of Health Sciences, Uskudar, Istanbul, Turkey
| | - Sevki Cinar
- Department of Prosthodontics, Faculty of Dentistry, University of Health Sciences, Uskudar, Istanbul, Turkey
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Souza LFB, Pilecco RO, Menna Barreto VS, Chiapinotto GF, Daudt NDF, Valandro LF, Pereira GKR. Pre-sintering pigmentation techniques do not affect the fatigue behavior of adhesively luted 4YSZ restorations. J Mech Behav Biomed Mater 2022; 132:105270. [PMID: 35617820 DOI: 10.1016/j.jmbbm.2022.105270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/05/2022] [Accepted: 05/11/2022] [Indexed: 11/20/2022]
Abstract
This study aims to characterize the effect of shading techniques on the fatigue behavior of a 4YSZ ceramic (4 mol% yttrium stabilized zirconia) adhesively bonded to a dentin analogue (fiber-reinforced epoxy resin). 4YSZ ceramic discs (IPS e.max ZirCAD, Ø = 10 mm and 1 mm of thickness) were allocated according to the factor 'shading technique' into 4 groups: Brush- unshaded ceramic disc (IPS e.max ZirCAD BL) pigmented at the pre-sintered stage with pigment solution applied manually using a round liner brush; Immersion- unshaded ceramic disc pigmented through immersion in the solution for 1 s on only one side of the ceramic disc; Manufacturer- specimens already shaded by the manufacturer (IPS e.max ZirCAD MT A2 - Manufacturer group); Control- a control condition with absence of pigment (i.e. non-pigmented specimens). The specimens were sintered and a spectrophotometer (SP60, EX- Rite) was used to ensure that the same perceived color (i.e. pigment saturation) was achieved in the different shading strategies (Manufacturer, Brush or Immersion groups). To do so, the color differences (ΔE00) were calculated using the CIEDE 2000 equation; and an ΔE00 of up to 1.77 was considered as an acceptability threshold. Dentin analogue discs were obtained (Ø = 10 mm and 2.5 mm of thickness) and randomly allocated into pairs with the 4YSZ ceramic discs. Next, the pairs were adhesively bonded using a resin cement (Multilink N). The bonded assemblies (n = 15) were tested for fatigue using the step-stress test method (frequency of 20 Hz; 10,000 cycles per step, initial load 200 N; step-size of 100 N, up to 700 N; and after, step-size of 50 N, until specimen failure/fracture or radial cracks). Fatigue failure load (FFL) and number of cycles for failure (CFF) were recorded for statistical analysis. Fractographic features were accessed, and complementary roughness, topography, grain size and phase content analyses were performed. No statistical differences were observed in the fatigue behavior among the non-shaded condition (Control group - 880 N) and the shaded specimens (Manufacturer - 887 N, Brush - 820 N, and Immersion - 850 N groups; p > 0.05). However, the use of a brush shading technique induced slightly inferior fatigue mechanical behavior of the restorative set compared to the specimens already shaded by the manufacturer (p = 0.027). No differences in Weibull modulus were observed among the tested groups. The specimens pigmented by the brush technique demonstrated a rougher surface, with statistically higher Rz values, in addition to a larger grain size in comparison to all other conditions (p< 0.05). No m-phase content was identified (only t and c phases were detected). Thus, the shading techniques used to provide a Vita classic A2 shade does not negatively affect the mechanical fatigue properties of a bonded 4YSZ ceramic. However, the brush technique has detrimental effect on the fatigue behavior compared to when the ceramic was already provided in a shaded format by its manufacturer.
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Affiliation(s)
- Luiza Freitas Brum Souza
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Rafaela Oliveira Pilecco
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | | | | | - Natália de Freitas Daudt
- MSciEng and PhD Post-Graduate Program in Mechanical Engineering, Faculty of Mechanical Engineering, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Luiz Felipe Valandro
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Gabriel Kalil Rocha Pereira
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
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Souza LFB, Soares PM, Chiapinotto GF, Ribeiro VF, Daudt NDF, Valandro LF, Pereira GKR. Effect of pigmentation techniques on the fatigue mechanical behavior of a translucent zirconia for monolithic restorations. J Mech Behav Biomed Mater 2022; 134:105362. [PMID: 35872462 DOI: 10.1016/j.jmbbm.2022.105362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/06/2022] [Accepted: 07/09/2022] [Indexed: 11/29/2022]
Abstract
This study aims to characterize the effect of pre- and/or post-sintering pigmentation techniques on the fatigue behavior of a 4YSZ ceramic (4 mol% yttrium stabilized zirconia). First, 4YSZ ceramic discs (IPS e.max ZirCAD, 15 mm diameter, and 1.2 mm thickness) were obtained and allocated according to the 'pigmentation technique' factor into 5 groups: Ctrl - unshaded ceramic disc (IPS e.max ZirCAD BL); Manuf - ceramic discs shaded by the manufacturer at block formation (IPS e.max ZirCAD MT A2); Brush - unshaded ceramic disc pigmented in the pre-sintered stage using a brush; Stain - unshaded ceramic disc pigmented in the post-sintering stage using a stain glaze (shade A2); Brush + Stain - combination of Brush and Stain techniques. The specimens were sintered and analyzed by a spectrophotometer (VITA Easyshade) for color differences (ΔE00 calculated according to CIEDE, 2000) to ensure that they present the same perceived color (ΔE00 ≤ 1.77, acceptability threshold). The specimens (n = 15) were submitted to biaxial flexural fatigue testing using a cyclic fatigue method (frequency of 20 Hz; 10,000 cycles per step; initial stress of 200 MPa; and step-size of 25 MPa) until specimen fracture. Fatigue strength (FS) and number of cycles until failure (CFF) were recorded with statistical purposes. Fractographic, complementary topography, elemental and roughness analyses were performed. The Ctrl shown the highest FS, CFF, and survival rates compared to the other conditions (p < 0.05), being only statistically similar to Brush. Stain showed the lowest FS, CFF and survival rates (p < 0.05). The Manuf and Brush + Stain shown intermediary performance. In regards of Weibull moduli, Brush shown the lowest values (lowest structural reliability), for both FS and CFF, being only statistically similar to Manuf. Topography analysis shown a uniform size of zirconia crystals in Ctrl, Manuf and Brush. In addition, a smooth glassy surface with some spots of impregnated pigment was observed in the groups where glaze was applied (Stain and Brush + Stain). This finding was corroborated by elemental analysis. Despite that, Stain and Brush + Stain presented the roughest surface (p < 0.05). In summary, the pigmentation techniques used to provide a Vita classical A2 color shade have a detrimental effect on the mechanical fatigue properties of a 4YSZ ceramic, except for the technique performed with the brush in the block pre-sintering stage. Despite this, the brush technique presents great variability in mechanical performance, resulting in lower structural reliability.
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Affiliation(s)
- Luiza Freitas Brum Souza
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Pablo Machado Soares
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Gratcheva Falcão Chiapinotto
- Graduate Program in Dentistry, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Vinícius Fogliato Ribeiro
- Graduate Program in Dentistry, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Natália de Freitas Daudt
- MSciD and PhD Post-Graduate Program in Mechanical Engineering, Faculty of Mechanical Engineering, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Luiz Felipe Valandro
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil; Graduate Program in Dentistry, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Gabriel Kalil Rocha Pereira
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil; Graduate Program in Dentistry, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
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Toma FR, Bîrdeanu MI, Uțu ID, Vasiliu RD, Moleriu LC, Porojan L. Surface Characteristics of High Translucent Multilayered Dental Zirconia Related to Aging. MATERIALS (BASEL, SWITZERLAND) 2022; 15:3606. [PMID: 35629636 PMCID: PMC9144863 DOI: 10.3390/ma15103606] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 02/06/2023]
Abstract
(1) Background: The purpose of this study was to evaluate the differences in terms of surface characteristics (roughness, topography, microhardness) among layers for multi-layered high translucent and super-high translucent zirconia and the influence of finishing and aging on surface characteristics and microstructure. (2) Methods: Three types of translucent multilayer zirconia were evaluated: STML (4Y-TZP); IPS e.maxZirCAD CEREC/in Lab MT Multi (4Y-TZP + 5Y-TZP); CeramillZolidfx ML (5Y-TZP). Ninety-six plate-shaped samples (32 for a material), 16 mm × 14 mm × 1 mm size, were cut with a precision disc, polished on both sides with sand papers and sintered respecting the manufacturer’s protocol. Half of the specimens (16) were finished by polishing and the other half by glazing and then equally divided into one control group and one group subject to aging by autoclaving (1 h, 134 °C, 0.2 MPa), resulting in four groups of eight samples, for each zirconia. The specimens were evaluated in three areas: cervical, medium, incisal-of each glazed or polished surface, before and after aging. Tests were performed to determine the surface roughness using a profilometer; the surface topography by an atomic force microscope (AFM) and a scanning electron microscope (SEM). Microhardness was recorded using a microhardness tester. Statistical analyses were performed using two-way ANOVA test, unpaired sample t-Test, paired sample t-Test (α = 0.05) and Pearson’s correlation. (3) Results: Before and after autoclaving, for glazed samples significance (p < 0.05) higher surface roughness, respectively lower microhardness in comparison with the polished group was assessed. No significant differences (p > 0.05) were reported between the three areas, on glazed or polished surfaces of a material. Although, after aging an increase in surface roughness was observed both on glazed and polished samples, statistical differences were found for STML (p < 0.05). No significant differences (p> 0.05) concerning microhardness among the same areas, on glazed and polished surfaces, recorded before and after aging, except CeramillZolidfx ML glazed samples. (4) Conclusions: For tested zirconia materials no significant differences among layers were registered regarding surface characteristics. Surface treatment (glazing or polishing) has a significant impact on surface roughness and microhardness. Both before and after aging, the surface roughness values for the glazed samples were higher than for those polished. The super translucent 4Y-TZP material was more affected by aging compared to the super-high translucent 5Y-TZP material. The combined material revealed similarities for each layer corresponding to the microstructure.
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Affiliation(s)
- Flavia Roxana Toma
- Department of Dental Prostheses Technology (Dental Technology), Center for Advanced Technologies in Dental Prosthodontics, Faculty of Dental Medicine, “Victor Babeș” University of Medicine and Pharmacy Timișoara, EftimieMurgu Sq. No. 2, 300041 Timisoara, Romania; (F.R.T.); (R.D.V.)
| | - Mihaela Ionela Bîrdeanu
- National Institute for Research and Development in Electrochemistry and Condensed Matter, 300569 Timisoara, Romania;
| | - Ion-Dragoș Uțu
- Department of Materials and Fabrication Engineering, Politehnica University Timişoara, Bd. Mihai Viteazu nr.1, 300222 Timisoara, Romania;
| | - Roxana Diana Vasiliu
- Department of Dental Prostheses Technology (Dental Technology), Center for Advanced Technologies in Dental Prosthodontics, Faculty of Dental Medicine, “Victor Babeș” University of Medicine and Pharmacy Timișoara, EftimieMurgu Sq. No. 2, 300041 Timisoara, Romania; (F.R.T.); (R.D.V.)
| | - Lavinia Cristina Moleriu
- Department of Functional Science, “Victor Babeș” University of Medicine and Pharmacy Timișoara, EftimieMurgu Sq. No. 2, 300041 Timisoara, Romania;
| | - Liliana Porojan
- Department of Dental Prostheses Technology (Dental Technology), Center for Advanced Technologies in Dental Prosthodontics, Faculty of Dental Medicine, “Victor Babeș” University of Medicine and Pharmacy Timișoara, EftimieMurgu Sq. No. 2, 300041 Timisoara, Romania; (F.R.T.); (R.D.V.)
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Čokić SM, Cóndor M, Vleugels J, Meerbeek BV, Oosterwyck HV, Inokoshi M, Zhang F. Mechanical properties-translucency-microstructure relationships in commercial monolayer and multilayer monolithic zirconia ceramics. Dent Mater 2022; 38:797-810. [PMID: 35450705 DOI: 10.1016/j.dental.2022.04.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 03/17/2022] [Accepted: 04/01/2022] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To evaluate the phase composition, microstructure, optical properties and mechanical properties of eight commercially available multilayer and monolayer monolithic dental zirconias. METHODS Five commercial 3Y-TZP (GC ST, GC HT [GC, Tokyo Japan]; Katana ML, Katana HT [Kuraray Noritake] and Lava Plus [3M Oral Care]) and three Y-PSZ (Katana STML, Katana UTML [Kuraray Noritake]; GC UHT [GC, Tokyo Japan]) zirconia ceramic grades were cut in plate-shaped specimens, sintered according to the manufacturer's instructions and mirror polished. The zirconia chemical composition was determined using X-ray fluorescence (XRF), phase composition was characterized using X-ray diffraction (XRD), while the grain size was measured using scanning electron microscopy (SEM). The translucency Parameter (TP) and Contrast Ratio (CR) were measured with a spectrophotometer (n = 10/group). The indentation fracture toughness (n = 10), Vickers hardness (n = 10) and biaxial strength (n = 20) of the sintered ceramics were assessed. The stress distribution during biaxial testing was assessed by Finite element analysis (FEA). Statistical analysis involved one-way ANOVA and post-hoc Tukey's HSD test and Pearson correlation test (α = 0.05). RESULTS FEA showed that the stress distribution in plate shape specimens was the same as for disks, rationalizing the use of plates for biaxial strength testing. As expected, higher quantities of Y2O3 were related to a higher cubic ZrO2 phase content and lower tetragonality t-ZrO2, which improved translucency but diminished flexural strength and toughness. While there was no significant correlation between grain size and other material properties, addition of pigments to the zirconia grade statistically negatively affected hardness. CONCLUSION Even though an improvement in strength and translucency could be recorded for the last Y-TZP generation, future research still needs to strive for combined improvement of optical properties and mechanical reliability of zirconia ceramics.
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Affiliation(s)
- Stevan M Čokić
- KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & UZ Leuven (University Hospitals Leuven), Dentistry, Leuven, Belgium.
| | - Mar Cóndor
- KU Leuven (University of Leuven), Department of Mechanical Engineering, Biomechanics Section (BMe), Arenberg, Leuven, Belgium
| | - Jef Vleugels
- KU Leuven (University of Leuven), Department of Materials Engineering (MTM), Kasteelpark Arenberg 44, B-3001 Leuven, Belgium
| | - Bart Van Meerbeek
- KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & UZ Leuven (University Hospitals Leuven), Dentistry, Leuven, Belgium
| | - Hans Van Oosterwyck
- KU Leuven (University of Leuven), Department of Mechanical Engineering, Biomechanics Section (BMe), Arenberg, Leuven, Belgium
| | - Masanao Inokoshi
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8549, Japan
| | - Fei Zhang
- KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & UZ Leuven (University Hospitals Leuven), Dentistry, Leuven, Belgium; KU Leuven (University of Leuven), Department of Materials Engineering (MTM), Kasteelpark Arenberg 44, B-3001 Leuven, Belgium
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ZHOU SHANYU, YOU YUEHUA, HU CHEN, SUN TING, SHAO LONGQUAN. FRACTOGRAPHIC ANALYSIS OF LITHIUM DISILICATE CERAMICS AND MONOLITHIC ZIRCONIA CERAMICS. J MECH MED BIOL 2022. [DOI: 10.1142/s0219519422400127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Objective: To compare the fracture mode of lithium disilicate ceramics and zirconia ceramics through a single-load-to-failure test, and reveal the cause of failure through the fractographic analysis of fracture morphology. Methods: Based on the standardized preparations, 10 IPS e.max disilicate ceramic crowns (IPCs) and 10 monolithic zirconia ceramic crowns (MZCs) were designed and fabricated. All the specimens were placed on a universal material testing machine for a single-load-to-failure test. The fracture load was recorded, and two independent sample [Formula: see text]-tests were performed. Additionally, the type of fracture under a stereo-microscope was observed, and the morphological characteristics of the fracture with a scanning electron microscope (SEM) were investigated. Results: The fracture load of the IPC group was [Formula: see text][Formula: see text]N, and that of the MZC group was [Formula: see text][Formula: see text]N, with a statistically significant difference ([Formula: see text], [Formula: see text]). The fracture types of the IPC group and the MZC group were similar, namely, types II and III. The fracture modes of the two groups were all ceramic layer fracture. Through SEM, the origin of the crack on the occlusal surface could be traced back. The crystal fracture of IPC group had a rock sugar-like pattern, and the crystal distribution of MZC group was uniform. Conclusions: Zirconia ceramics have higher fracture load and a denser crystal structure compared to lithium disilicate. Fractographic analysis method could be a better way to analyze the failure mode of single-layer porcelain materials and reveal the origin of fracture.
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Affiliation(s)
- SHANYU ZHOU
- Department of Stomatology, Affiliated Longhua People’s Hospital, Southern Medical University, Shenzhen, Guangdong 518109, P. R. China
| | - YUEHUA YOU
- Department of Stomatology, Affiliated Longhua People’s Hospital, Southern Medical University, Shenzhen, Guangdong 518109, P. R. China
| | - CHEN HU
- Department of Stomatology, Nanfang Hospital, Southern Medical University Guangzhou, Guangdong 510515, P. R. China
| | - TING SUN
- The Affiliated Stomatology Hospital, Foshan University, Foshan, Guangdong 528000, P. R. China
| | - LONGQUAN SHAO
- Department of Stomatology, Nanfang Hospital, Southern Medical University Guangzhou, Guangdong 510515, P. R. China
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Zhang CN, Zhu Y, Zhang YJ, Jiang YH. Clinical esthetic comparison between monolithic high-translucency multilayer zirconia and traditional veneered zirconia for single implant restoration in maxillary esthetic areas: Prosthetic and patient-centered outcomes. J Dent Sci 2022; 17:1151-1159. [PMID: 35784115 PMCID: PMC9236935 DOI: 10.1016/j.jds.2022.01.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/14/2022] [Indexed: 11/19/2022] Open
Abstract
Background/purpose Clinical esthetic evidence for the performance of monolithic high-translucency multilayer zirconia is lacking. The aim of this study was to compare monolithic high-translucency multilayer zirconia with traditional veneered zirconia in clinical situation. Material and methods A total of 30 participants who were provided with both monolithic zirconia crowns (Group 1) and traditional veneered crowns (Group 2) for single implant restoration in maxillary esthetic areas were enrolled. Patients' subjective outcome (Visual Analog Scale, VAS) were recorded. Photos were taken and then evaluated by 9 evaluators with Pink and White Esthetic Score (WES). Wilcoxon signed rank test was used for comparison between Group 1 and Group 2 in VAS, WES and five variables in WES. Kendall's coefficient of concordance test was used to calculate inter-rater reliability of WES variables. Spearman correlation was used to analyze association between patients' outcome and evaluators' scores. Results There was no significant difference in patients' subjective outcome between monolithic zirconia and traditional veneered crowns: overall VAS were 9.0 (8.0–9.0) and 9.0 (8.5–9.5), respectively (P > 0.05). However, in professional view, significant difference between Group 1 and Group 2 in WES was observed: 7.5 (6.0–8.0) and 8.0 (6.5–8.5), respectively (P < 0.05). Kendall's test showed, among WES variables, translucency demonstrated the highest agreement. Professionally reported evaluations did not correlate with patient-reported outcomes (Spearman correlation were 0.246 and 0.224 for Group 1 and Group 2, respectively). Conclusion Within the limitation of this study, it can be concluded that monolithic high-translucency multilayer zirconia restoration might be a treatment modality.
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Affiliation(s)
- Chu-Nan Zhang
- Department of Implant Dentistry, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, China
| | - Yu Zhu
- Department of Implant Dentistry, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, China
| | - Yi-Jie Zhang
- Department of Implant Dentistry, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, China
| | - Yin-Hua Jiang
- Department of Oral and Maxillofacial Implantology, Lishui People’s Hospital, The Sixth Affiliated Hospital of Wenzhou Medical University, Lishui, China
- Corresponding author. Department of Oral and Maxillofacial Implantology, Lishui People's Hospital, The Sixth Affiliated Hospital of Wenzhou Medical University, No. 15 Dazhong Road, Lishui, 323000, China. Fax: +86 0578 2187120.
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Zhang CY, Agingu C, Yang H, Cheng H, Yu H. Effects of Hydrothermal Treatment on the Phase Transformation, Surface Roughness, and Mechanical Properties of Monolithic Translucent Zirconia. Oper Dent 2022; 47:76-86. [PMID: 34979031 DOI: 10.2341/20-270-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2021] [Indexed: 11/23/2022]
Abstract
OBJECTIVES This study aimed to investigate the effects of hydrothermal treatment on four types of monolithic, translucent, yttria-stabilized, tetragonal zirconia polycrystals (Y-TZPs). METHODS AND MATERIALS Two commercially available Y-TZP brands-SuperfectZir High Translucency (Aidite Technology Co, China) and Katana HT (Kuraray Noritake Dental, Japan) were assessed. For each brand of Y-TZP, materials of four coloring types, including noncolored (NC), colored by staining (CS), precolored (PC), and multilayered (ML) specimens were investigated after hydrothermal aging in an autoclave at 134°C/0.2 MPa for 0 (control group), 5, 10, and 20 hours. The tetragonal-to-monoclinic phase transformation, surface roughness, flexural strength, and structural reliability (Weibull analysis) were measured and statistically analyzed (α=0.05). The subsurface microstructure was analyzed with scanning electron microscopy. RESULTS The group ML exhibited the lowest flexural strength and Weibull characteristic strength among the four coloring types (p<0.05). Slight increases in the monoclinic phase volume, flexural strength, and Weibull characteristic strength were observed after hydrothermal aging (pall<0.05). Regardless of coloring type, no significant effects of aging on the Weibull modulus or surface roughness were found for the tested materials. Compared with the Katana HT cross-sections, the SuperfectZir High Translucency cross-sections exhibited a similar but thicker transformation zone. CONCLUSIONS The coloring procedure and material type were found to affect the mechanical properties and aging resistance of translucent monolithic Y-TZP ceramics. Regardless of the aging time, the surface roughness of the tested Y-TZP ceramics remained unchanged.
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Affiliation(s)
- C Y Zhang
- Chang-yuan Zhang, DDS, PhD, associate professor, Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - C Agingu
- Check Agingu, Master's student, Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - H Yang
- Hui Yang, Master's student, Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - H Cheng
- Hui Cheng, DDS, PhD, professor and associate dean, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - H Yu
- *Hao Yu, DDS, PhD, Dr med dent, associate professor and associate dean, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China; Adjunct Professor, Department of Applied Prosthodontics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
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de Araújo Neto VG, Soto-Montero J, de Castro EF, Feitosa VP, Rueggeberg FA, Giannini M. Effects of shades of a multilayered zirconia on light transmission, monomer conversion, and bond strength of resin cement. J ESTHET RESTOR DENT 2021; 34:412-422. [PMID: 34569699 DOI: 10.1111/jerd.12821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 09/11/2021] [Accepted: 09/14/2021] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate the influence of shades of a multilayered zirconia on light transmission, resin cement degree of conversion, and shear bond strength of resin cement. MATERIALS AND METHODS The light transmission through opaque (OPQ) and translucent (TNS) regions of Katana UTML zirconia (Kuraray Noritake Dental) were evaluated for using a spectroradiometer (n = 5). Degree of conversion of dual-cure resin cement (Panavia V5, Kuraray Noritake Dental) was measured after light-activation through OPQ or TNS regions and direct exposure. Composition of the zirconia was analyzed with energy dispersive x-ray spectroscopy (EDS). Shear bond strength (SBS) was evaluated on the OPQ and TNS regions after 24 h and 1 year from specimen preparation (n = 15). RESULTS The OPQ region produced higher irradiance loss (95.1%) than TNS one (92.9%), and lower degree of conversion (52.4%) than TNS (71.2%) at 24 h post-light activation. EDS analysis did not show differences on the microstructure of the OPQ and TNS regions. There were no significant differences on the SBS between zirconia regions. For both zirconia regions, a significant reduction on the SBS occurred after aging, being 31.7% for OPQ and 38% for TNS. CONCLUSION Both OPQ and TNS regions affected the light transmission through the multilayered zirconia. The OPQ region yielded the highest light attenuation and the lowest degree of conversion of resin cement. Different regions of the zirconia did not influence the SBS. Clinical significance Although opaque and translucent regions of the multilayered zirconia reduced the light transmission from LED curing unit and the degree of conversion of resin cement, the regions did not affect the resin cement adhesion.
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Affiliation(s)
| | - Jorge Soto-Montero
- Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.,Department of Restorative Dentistry, Faculty of Dentistry, University of Costa Rica, San José, Costa Rica
| | - Eduardo Fernandes de Castro
- Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | | | | | - Marcelo Giannini
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Piracicaba, SP, Brazil
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Effects of thickness of different types of high-translucency monolithic multilayer precolored zirconia on color accuracy: An in vitro study. J Prosthet Dent 2021; 126:587.e1-587.e8. [PMID: 34446291 DOI: 10.1016/j.prosdent.2021.07.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 07/16/2021] [Accepted: 07/16/2021] [Indexed: 11/21/2022]
Abstract
STATEMENT OF PROBLEM High-translucency monolithic multilayer precolored zirconia provides acceptable esthetics and eliminates chipping of the veneering porcelain. However, the color is not always consistent with the standard Vita shade guide, and the color saturation may vary with the thickness of the zirconia. PURPOSE The purpose of this in vitro study was to characterize the effect of thickness on the color accuracy of high-translucency monolithic multilayer precolored zirconia. MATERIAL AND METHODS Plate-shaped (20×20 mm) Vita A2 shade high-translucency monolithic multilayer precolored zirconia specimens of 3 types (SHT Multilayer, AT Multilayer, and 3D Multilayer) in 4 thicknesses (0.5, 1.0, 1.5, and 2.0 mm) were fabricated (N=120, n=10). A spectrophotometer was used to measure the color attributes (CIELab) against gray or A2 substrates to evaluate the color accuracy based on differences in color (ΔE) (versus the Vita shade guide) and chroma. Statistical analysis was performed by using the Pearson correlation, 2-way ANOVA, and post hoc Scheffé test (α=.05). RESULTS Against gray substrates, thickness was significantly positively correlated with all color attributes. Against A2 substrates, L∗ values increased with an increase in thickness; however, a∗, b∗, and chroma values remained stable. Zirconia with a thickness of 1.0 mm exhibited the lowest ΔE, regardless of the type, except for AT Multilayer against A2 substrates, where the lowest ΔE was achieved at 0.5 mm. At thicknesses ≥1.0 mm, the ΔE between the 2 substrates was imperceivable. CONCLUSIONS Thickness affected the color accuracy of different high-translucency monolithic multilayer precolored zirconia types. It appears that the optimal thickness in terms of color accuracy is 1.0 mm. These results could be used as a reference for the selection and preparation of abutments in clinical applications.
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Corcodel N, Herpel C, Seceleanu I, Rion K, Hassel AJ, Rammelsberg P. Effect of grinding adjustments on the color of monolithic zirconia. J Prosthet Dent 2021; 128:1075-1083. [PMID: 33896619 DOI: 10.1016/j.prosdent.2021.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 03/01/2021] [Accepted: 03/01/2021] [Indexed: 11/17/2022]
Abstract
STATEMENT OF PROBLEM Monolithic zirconia restorations have become popular because of their excellent mechanical properties and acceptable esthetics. While the biomechanical properties of zirconia have been investigated, research into their esthetic properties is sparse. Zirconia can be colored by infiltration before sintering, although how occlusal adjustment can affect restoration color is unclear. PURPOSE The purpose of this in vitro study was to analyze the color of differently characterized monolithic white and precolored zirconia specimens after standardized grinding. MATERIAL AND METHODS White and precolored monolithic zirconia plates (Cercon ht) (n=36) were stained by infiltration with target colors Vita A2, A3.5, and A4. In a standardized experimental arrangement, all plates were ground in 9 steps, and the color was measured with a spectroradiometer at each step. Color differences (ΔE00) were analyzed by using regression analysis, the Kruskal-Wallis test, and the inverse prediction with confidence intervals (α=.05). RESULTS Mechanical material removal had a significant effect on the color stability (P<.05) of both white and precolored monolithic zirconia. For each grinding step and each target color, the precolored groups had a significantly lower ΔE00 mean than the white groups (P<.05), except at the 20-μm step for groups W-A4 and P-A4 (P>.05). For target color A2, the difference was significant with P<.001 at all 9 grinding steps. For target color A3.5, the difference was significant with P=.003 at grinding level 20 μm, and P<.001 for all other grinding steps. For target color A4, the difference was not significant with P=.603 at grinding level 20 μm, whereas the difference was significant with P=.007 at grinding level 50 μm, and with P<.001 for all other grinding steps. CONCLUSIONS Precolored zirconia had less color change after grinding than white zirconia. This study established grinding depths for white and precolored zirconia corresponding to color perceptibility and acceptability thresholds.
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Affiliation(s)
- Nicoleta Corcodel
- Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany.
| | - Christopher Herpel
- Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
| | - Irina Seceleanu
- Associate Professor, Department of Mathematics, Bridgewater State University, Bridgewater, Mass
| | - Kevin Rion
- Associate Professor, Department of Mathematics, Bridgewater State University, Bridgewater, Mass
| | - Alexander Jochen Hassel
- Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
| | - Peter Rammelsberg
- Professor and Head, Department of Prosthodontics, University of Heidelberg, Heidelberg, Germany
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Effects of Aging on the Color and Translucency of Monolithic Translucent Y-TZP Ceramics: A Systematic Review and Meta-Analysis of In Vitro Studies. BIOMED RESEARCH INTERNATIONAL 2021; 2021:8875023. [PMID: 33575352 PMCID: PMC7857873 DOI: 10.1155/2021/8875023] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 12/08/2020] [Accepted: 01/11/2021] [Indexed: 11/27/2022]
Abstract
Background Monolithic restorations made of translucent yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) have become popular over the past few decades. However, whether aging affects the color and translucency of monolithic translucent Y-TZP is unclear. Objective The aim of this systematic review and meta-analysis of in vitro studies was to evaluate the effects of aging on the color and translucency of monolithic translucent Y-TZP ceramics. Materials and Methods This systematic review/meta-analysis was reported according to the PRISMA statement and registered in the OSF registries (https://osf.io/5qjmu). Four databases including Medline via the PubMed, Embase, and Web of Science databases and the Cochrane Library were searched using no publication year and language limits. The last search was executed on November 20, 2020. In vitro studies comparing the translucency and/or color of monolithic translucent Y-TZP ceramics before and after simulated aging were selected. Meta-analyses were performed using Review Manager software (version 5.3, Cochrane Collaboration, Oxford, UK) with random-effects models at a significance level of 0.05. A risk-of-bias assessment was also performed for the included studies. Results Of the 188 potentially relevant studies, 13 were included in the systematic review. The hydrothermal aging duration ranged from 1 to 100 h at relatively similar temperatures (~134°C). In the general meta-analyses, the aged Y-TZP ceramics exhibited similar translucency parameter (TP), L∗, and b∗ values compared with the nonaged controls (P = .73, P = .49, and P = .62, respectively). Moreover, there was a significant difference between the aged and nonaged Y-TZP ceramics in the a∗ value (P = .03; MD = −0.26; 95% CI = −0.51 to − 0.02), favoring the nonaged Y-TZP ceramics. The subgroup analyses showed that the duration of aging contributed to changes in the translucency and color of the Y-TZP ceramics. Conclusions The optical properties of monolithic translucent Y-TZP ceramics were stable after hydrothermal aging at 134°C and 0.2 MPa for ≤20 h. Moreover, clinically unacceptable changes in the translucency and color of monolithic translucent Y-TZP ceramics were found after hydrothermal aging for >20 h.
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Influence of coloring liquid immersion on flexural strength, Vickers hardness, and color of zirconia. J Prosthet Dent 2021; 126:589.e1-589.e6. [PMID: 33423819 DOI: 10.1016/j.prosdent.2020.11.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 11/13/2020] [Accepted: 11/16/2020] [Indexed: 11/23/2022]
Abstract
STATEMENT OF PROBLEM Zirconia is a widely used restorative material, yet its white color does not meet esthetic requirements and coloring is needed. However, the effects of different durations of coloring have not been thoroughly investigated. PURPOSE The purpose of this in vitro study was to evaluate the effects of coloring liquid immersion of different durations on the flexural strength, Vickers hardness, and color of zirconia. MATERIAL AND METHODS Fifty bar-shaped and 60 disk-shaped zirconia specimens were milled from nonshaded (Copran Zri) and preshaded (Copran Zri Precoloured Medium) disks by using a computer-aided design and computer-aided manufacturing (CAD-CAM) system. Preshaded specimens were assigned to the group PS and received no further immersion. Nonshaded specimens were divided into 4 subgroups as per immersion time in coloring liquid (Copran Color A2 Shade): control (C; no immersion), G45 (45 seconds of immersion), G90 (90 seconds of immersion), and G135 (135 seconds of immersion). Bar-shaped specimens were subjected to a 3-point flexural strength test by using a universal testing machine (Lloyd LRX), following the International Organization for Standardization (ISO) 6872:2015 specification. Color coordinates of disk-shaped specimens were measured with a spectrophotometer (VITA Easyshade Advance 4.0) over a gray background. Color differences were calculated by using both CIE76 and CIEDE2000 formulas, followed by a comparison of obtained values with perceptibility (CIE76: 3.7, CIEDE2000: 0.8) and acceptability (CIE76: 6.8, CIEDE2000: 1.8) thresholds of each formula. Subsequently, Vickers hardness measurements were conducted. The data were statistically analyzed by using the Shapiro-Wilk test, 1-way ANOVA, and the Tukey HSD test (α=.05). RESULTS Immersing zirconia specimens in coloring liquid decreased the flexural strength and hardness values, as group C presented the highest values for both parameters. In addition, prolonged duration had a negative effect on mechanical properties. The flexural strength of groups PS and G45 (P=.993) and groups G90 and G135 (P=.999) was statistically similar. For Vickers hardness, group G135 presented the lowest values with the difference between groups G90 and G135 being statistically similar (P=.061). Color differences among groups varied from 2.49 to 27.33 for ΔE∗, whereas ΔE00 values ranged from 0.58 to 8.26. Compared with group C, ΔE∗ values of all shaded specimens exceeded the acceptability threshold of 6.8. The color difference between each group was higher than the acceptability threshold values of both ΔE∗ and ΔE00 except for groups G45 and PS. CONCLUSIONS Colored zirconia specimens had lower flexural strength and Vickers hardness values than nonshaded specimens, regardless of the immersion time or coloring technique.
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Ceramic Materials and Technologies Applied to Digital Works in Implant-Supported Restorative Dentistry. MATERIALS 2020; 13:ma13081964. [PMID: 32331379 PMCID: PMC7216107 DOI: 10.3390/ma13081964] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/14/2020] [Accepted: 04/20/2020] [Indexed: 12/17/2022]
Abstract
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.
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Impact of hydrothermal aging on the light transmittance and flexural strength of colored yttria-stabilized zirconia materials of different formulations. J Prosthet Dent 2020; 125:518-526. [PMID: 32199639 DOI: 10.1016/j.prosdent.2020.01.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/23/2020] [Accepted: 01/23/2020] [Indexed: 11/21/2022]
Abstract
STATEMENT OF PROBLEM Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) materials of different formulations (3Y-TZP, 4Y-TZP, and 5Y-TZP) can be colored by using color liquids. However, practically and clinically relevant factors such as modifications of sintering protocols and hydrothermal aging might affect the extent of light transmittance and flexural strength of zirconia materials of different formulations; studies on these outcomes, however, are lacking. PURPOSE The purpose of this in vitro study was to test the impact of hydrothermal aging on the light transmittance and flexural strength of colored zirconia materials compared with a lithium-disilicate (LiSi2) ceramic. MATERIAL AND METHODS A total of 210 specimens were prepared from 3Y-TZP0.25 (n=30), 3Y-TZP0.05 (n=30), 5Y-TZP (n=30), 4Y-TZP (n=60), pre4Y-TZP (preshaded, n=30), and LiSi2 (n=30). All specimens, except for pre4Y-TZP and LiSi2, were manually colored, predried, and either conventionally sintered at 1450 °C (3Y-TZP0.25, 3Y-TZP0.05, 5Y-TZP, and half of 4Y-TZP) or high-speed sintered at 1580 °C (other half of 4Y-TZP and pre4Y-TZP). Light transmittance was measured initially and after 2, 5, 10, 20, 40, and 160 hours of hydrothermal aging (134 °C, 0.2 MPa). Biaxial flexural strength was tested initially and after 160 hours of hydrothermal aging (n=15). The Kolmogorov-Smirnov test, multivariate analysis, and 1-way ANOVA with the Tukey HSD post hoc test, the t test, and linear mixed models were calculated (α=.05). RESULTS LiSi2 showed the highest translucency, followed by 5Y-TZP, 4Y-TZP, pre4Y-TZPspeed, 3Y-TZP0.05, and 3Y-TZP0.25. 4Y-TZPspeed was most opaque and matte. The decrease in translucency related to aging hours was higher for LiS2 and conventional sintered zirconia materials than for 4Y-TZPspeed and pre4Y-TZPspeed. Initially, 3Y-TZP0.25 had the highest flexural strength, followed by 3Y-TZP0.05, 4Y-TZP, and pre4Y-TZPspeed. pre4Y-TZPspeed was comparable with 4Y-TZPspeed but significantly higher than 5Y-TZP. LiSi2 had the lowest biaxial flexural strength. Hydrothermal aging increased biaxial flexural strength for 3Y-TZP0.25 and 3Y-TZP0.05 (P<.001) but decreased it for 5Y-TZP (P=.005) and pre4Y-TZPspeed (P<.001). After aging, 4Y-TZPspeed showed comparable values of flexural strength with 4Y-TZP (P=.06) and higher values than pre4Y-TZPspeed after aging (P=.019). CONCLUSIONS Manually colored, conventionally sintered 4Y-TZP was resistant to hydrothermal aging regarding flexural strength. High-speed sintering inhibited color development for manually colored 4Y-TZP but did not affect the resistance to hydrothermal aging. The findings were reversed for industrially preshaded 4Y-TZP.
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Giti R, Haghdoost S, Ansarifard E. Effect of different coloring techniques and surface treatment methods on the surface roughness of monolithic zirconia. Dent Res J (Isfahan) 2020. [DOI: 10.4103/1735-3327.280893] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Kontonasaki E, Giasimakopoulos P, Rigos AE. Strength and aging resistance of monolithic zirconia: an update to current knowledge. JAPANESE DENTAL SCIENCE REVIEW 2019; 56:1-23. [PMID: 31768195 PMCID: PMC6872834 DOI: 10.1016/j.jdsr.2019.09.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 08/02/2019] [Accepted: 09/17/2019] [Indexed: 01/01/2023] Open
Abstract
New zirconia compositions with optimized esthetic properties have emerged due to the fast-growing technology in zirconia manufacturing. However, the large variety of commercial products and synthesis routes, make impossible to include all of them under the general term of “monolithic zirconia ceramics”. Ultra- or high translucent monolithic formulations contain 3–8 mol% yttria, which results in materials with completely different structure, optical and mechanical properties. The purpose of this study was to provide an update to the current knowledge concerning monolithic zirconia and to review factors related to strength and aging resistance. Factors such as composition, coloring procedures, sintering method and temperature, may affect both strength and aging resistance to a more or less extend. A significant reduction of mechanical properties has been correlated to high translucent zirconia formualtions while regarding aging resistance, the findings are contradictory, necessitating more and thorough investigation. Despite the obvious advantages of contemporary monolithic zirconia ceramics, further scientific evidence is required that will eventually lead to the appropriate laboratory and clinical guidelines for their use. Until then, a safe suggestion should be to utilize high-strength partially-stabilized zirconia for posterior or long span restorations and fully-stabilized ultra-translucent zirconia for anterior single crowns and short span fixed partial dentures.
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Affiliation(s)
- Eleana Kontonasaki
- Department of Prosthodontics, Faculty of Dentistry, School of Health Sciences, Aristotle University of Thessaloniki, Greece
- Corresponding author at: Laboratory of Prosthodontics, Department of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki GR-54124, Greece.
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Bittar BF, Miranda JS, Simões AC, de Carvalho Ramos N, Machado JPB, Zhang Y, Souza ROA, Leite FPP. Effect of extrinsic pigmentation and surface treatments on biaxial flexure strength after cyclic loading of a translucent ZrO 2 ceramic. Dent Mater 2019; 35:1644-1653. [PMID: 31575489 PMCID: PMC6858620 DOI: 10.1016/j.dental.2019.08.117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 08/12/2019] [Accepted: 08/31/2019] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the influence of extrinsic pigmentation on the biaxial flexural strength and surface topographic of translucent Y-TZP (InCoris TZI - Sirona - USA) subjected to several surface treatments. METHODS Sintered zirconia discs-shaped specimens (n=120) (ø:12mm; thickness:1.2mm; ISO 6872) were prepared and divided (n=15) according to various factors: "extrinsic pigmentation" (n: without; p: with) and "surface treatments" (C: control - as sintered; A: abraded with silica-coated alumina particles (30μm); G: glazed with a thin film of low-fusing porcelain glaze; GH: glazed and etched with 10% hydrofluoridric acid for 60s. Mechanical cycling (1.2×106 cycles, 200N, 3.8Hz) and flexural strength test (1mm/min - 1000kg cell) were performed. Two-way ANOVA and Tukey's were used for statistical test (α=0.05). Weibull analysis was used to evaluate the strength reliability. Samples were analyzed via (1) an optical profilometer to determine the surface roughness (Ra); (2) an X-ray diffraction (XRD) to evaluate phase transformations; and (3) a SEM equipped with an energy dispersive X-ray spectroscopy (EDX) to elucidate morphological properties and chemical compositions. RESULTS Regardless of the surface treatment (p=0.5459) (Cn: 560.16MPa; Gn: 573.36MPa; An: 643.51MPa; GHn: 542.94MPa; Cp: 628.04MPa; Gp: 641.90MPa; Ap: 554.47MPa; GHp :602.84MPa) and extrinsic pigmentation (p=0.1280) there was no difference in the flexural strength among the experimental groups. According to the XRD analysis, phase transformations occurred in the An group (t→m) and in Ap group (t→c). Surface roughness was affected by surface treatments (An - p=0.001) and extrinsic pigmentation (Gp - p=0.001). SIGNIFICANCE The biaxial flexural strength of the tested samples was not affected neither by surface treatments nor by pigmentation, although it can cause phase transformation and promote surface roughness.
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Affiliation(s)
- Breno Fortes Bittar
- Department of Restorative Dentistry, Federal University of Juiz de Fora (UFJF), Juiz de Fora/MG, Brazil
| | - Jean Soares Miranda
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University - UNESP, São José dos Campos, São Paulo, Brazil
| | - Arthur Chaves Simões
- Department of Restorative Dentistry, Federal University of Juiz de Fora (UFJF), Juiz de Fora/MG, Brazil
| | - Nathália de Carvalho Ramos
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University - UNESP, São José dos Campos, São Paulo, Brazil
| | - João P B Machado
- Federal University of Rio Grande do Norte/UFRN, Health Science Center, Department of Dentistry, Natal-RN/Brazil
| | - Yu Zhang
- New York University College of Dentistry, Department of Biomaterials and Biomimetics, 433 First Avenue, Room 810, New York, NY 10010, USA
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Auzani ML, Dapieve KS, Zucuni CP, Rocha Pereira GK, Valandro LF. Influence of shading technique on mechanical fatigue performance and optical properties of a 4Y-TZP ceramic for monolithic restorations. J Mech Behav Biomed Mater 2019; 102:103457. [PMID: 31605929 DOI: 10.1016/j.jmbbm.2019.103457] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 09/26/2019] [Accepted: 09/28/2019] [Indexed: 10/25/2022]
Abstract
This study aimed to evaluate the effect of shading procedures on the fatigue performance and optical properties of an yttria-stabilized tetragonal zirconia polycrystal ceramic (4Y-TZP - stabilized by 4 mol% Y2O3). Disc-shaped specimens were produced at pre-sintered stage and randomly allocated into 5 groups (n=15) considering the shading technique: Ctrl (no pigmentation); Brush 1× and Brush 3× (brushing on 1 or 3 applications, respectively); Immer 2min and Immer 4min (immersion for 2 or 4 min, respectively). Following each pigment application, the specimens were dried in accordance with the manufacturers' guidelines (15 min in a stove at 70 °C) and sintered in a specific furnace. Biaxial flexural fatigue test followed a step-stress approach (initial strength: 200 MPa; step-size: 25 MPa; 10.000 cycles/step; frequency: 20 Hz). Optical measurements were conducted in a spectrophotometer following the CIEDE2000 parameters. Roughness, topography, crystalline grain size, crystalline phase content and fractography analysis were also performed. The flexural fatigue strength (FFS) and the number of cycles to fracture (CFF) were statistically affected by pigmentation techniques (mean FFS in MPa/mean CFF): Ctrl (446.7/105,619) > Brush 1 × (436.7/102,854) ≥ Brush 3 × (405.0/89,962) ≥ Immer 2 min (395.0/85,103) ≥ Immer 4 min (383.3/81,382), although the exposure intensity (increase in number of applications or in application time) to the pigment had no effect (Brush 1 × = Brush 3 × ; Immer 2 min = Immer 4 min). Regarding optical properties, shading techniques similarly affected translucency and opalescence parameters, regardless of the exposure intensity to the pigment (Brush 1 × = Brush 3 × = Immer 2 min = Immer 4 min > Ctrl), whereas the exposure intensity to the pigment only promoted relevant alterations in the color change parameter (ΔE00) for the brushing technique (Brush 3 × > Brush 1 × ). No difference was observed in crystalline phase content, topographic pattern or roughness, although an increase in the zirconia grain size could be detected. Thus, the shading technique might affect the fatigue behavior and promote optical changes in a 4Y-TZP ceramic.
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Affiliation(s)
- Maria Luiza Auzani
- MSciD and PhD Graduate Programs in Oral Science - Prosthodontic Units, Faculty of Odontology, Federal University of Santa Maria - UFSM, Santa Maria, Rio Grande do Sul, Brazil.
| | - Kiara Serafini Dapieve
- MSciD and PhD Graduate Programs in Oral Science - Prosthodontic Units, Faculty of Odontology, Federal University of Santa Maria - UFSM, Santa Maria, Rio Grande do Sul, Brazil.
| | - Camila Pauleski Zucuni
- MSciD and PhD Graduate Programs in Oral Science - Prosthodontic Units, Faculty of Odontology, Federal University of Santa Maria - UFSM, Santa Maria, Rio Grande do Sul, Brazil.
| | - Gabriel Kalil Rocha Pereira
- MSciD and PhD Graduate Programs in Oral Science - Prosthodontic Units, Faculty of Odontology, Federal University of Santa Maria - UFSM, Santa Maria, Rio Grande do Sul, Brazil.
| | - Luiz Felipe Valandro
- MSciD and PhD Graduate Programs in Oral Science - Prosthodontic Units, Faculty of Odontology, Federal University of Santa Maria - UFSM, Santa Maria, Rio Grande do Sul, Brazil.
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Yu NK, Park MG. Effect of different coloring liquids on the flexural strength of multilayered zirconia. J Adv Prosthodont 2019; 11:209-214. [PMID: 31497268 PMCID: PMC6718843 DOI: 10.4047/jap.2019.11.4.209] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 06/13/2019] [Accepted: 08/14/2019] [Indexed: 11/15/2022] Open
Abstract
PURPOSE The purpose of this study was to evaluate the effect of two coloring liquids (aqueous and acid-based coloring liquids) and the position of multilayered zirconia on the flexural strength of multilayered zirconia. MATERIALS AND METHODS The multilayered zirconia specimens were divided into upper and lower positions. The specimens were divided into three subgroups (n=10): non-shaded, acid-based coloring liquid, and aqueous coloring liquid. The specimens were cut using a milling machine and were immersed in either a acid-based coloring liquid or aqueous coloring liquid 2 times for 5 seconds. The specimens were sintered in a sintering furnace according to the manufacturer's introduction. The flexural strength of the specimen was measured using a universal testing machine and the surface of the specimen was observed using a field emission scanning electron microscope. RESULTS The flexural strength of multilayered zirconia was 400 – 500 MPa. There was no statistically significant difference among all groups (P>.05).The flexural strength of the multilayered zirconia was not influenced by the kind of coloring liquid used (P>.05). The flexural strength of the multilayered zirconia colored with the coloring liquids was not influenced by its position (P>.05). CONCLUSION The different coloring liquid application did not affect the flexural strength of multilayered zirconia of all positions.
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Affiliation(s)
- Na-Kyoung Yu
- Department of Dental Laboratory Science, College of Health Sciences, Catholic University of Pusan, Busan, Republic of Korea
| | - Mi-Gyoung Park
- Department of Dental Laboratory Science, College of Health Sciences, Catholic University of Pusan, Busan, Republic of Korea
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Peng TY, Shimoe S, Tanoue N, Akebono H, Murayama T, Satoda T. Fatigue resistance of yttria-stabilized tetragonal zirconia polycrystal clasps for removable partial dentures. Eur J Oral Sci 2019; 127:269-275. [PMID: 31002752 DOI: 10.1111/eos.12615] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2019] [Indexed: 01/16/2023]
Abstract
With the rapid development of computer-aided design/computer-aided manufacturing (CAD/CAM) systems, the application of zirconia in removable partial dentures is expected to expand. Clasps composed of zirconia should improve esthetics without inducing the risk of metal allergy. The aim of this study was to examine the fatigue resistance of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) clasps for removable partial dentures. Yttria-stabilized tetragonal zirconia polycrystal and cobalt-chromium (Co-Cr) alloy were prepared using CAD/CAM systems. Specimens were either of the semicircular type or of the flat type, with cross-sectional areas of taper ratios of 0.50, 0.75, and 1.00. All specimens were tested using the cantilever test and the constant displacement fatigue test, and data were analyzed using ANOVA. During the cantilever test, the maximum displacement prior to fracture was greater than the required undercut, and the semicircular-type specimen exhibited a higher fracture load than the flat type. None of the specimens displayed permanent deformation and showed almost the same degree of deformation after fatigue testing. A lower taper ratio was associated with lower average load values and greater displacement. Within the limitations of this study, it was possible to conclude that Y-TZP provides the required undercut and adequate retentive force for removable partial denture clasps. Additionally, Y-TZP and Co-Cr alloy had almost the same degree of deformation even after the simulated lifespan of removable partial dentures.
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Affiliation(s)
- Tzu-Yu Peng
- Department of Anatomy and Functional Restorations, Integrated Health Sciences, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan
| | - Saiji Shimoe
- Department of Anatomy and Functional Restorations, Integrated Health Sciences, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan
| | - Naomi Tanoue
- Department of Special Care Dentistry, Nagasaki University Hospital, Nagasaki, Japan
| | - Hiroyuki Akebono
- Department of Mechanical Science and Engineering, Hiroshima University Graduate School of Engineering, Higashi-hiroshima, Japan
| | - Takeshi Murayama
- Department of Medical System Engineering, Integrated Health Sciences, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan
| | - Takahiro Satoda
- Department of Anatomy and Functional Restorations, Integrated Health Sciences, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan
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Vickers Micro-Hardness of New Restorative CAD/CAM Dental Materials: Evaluation and Comparison after Exposure to Acidic Drink. MATERIALS 2019; 12:ma12081246. [PMID: 31014032 PMCID: PMC6515223 DOI: 10.3390/ma12081246] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 03/29/2019] [Accepted: 04/11/2019] [Indexed: 11/16/2022]
Abstract
CAD/CAM (computer-aided design/computer-aided manufacturing) for indirect restorative materials has been recently introduced in dentistry. The purpose of this study was to evaluate the change of the surface micro-hardness of different restorative CAD/CAM materials after exposure to a carbonated acidic drink (Coca-Cola, Coca-Cola Company, Milan, Italy). One hundred and eighty specimens of identical size (2 mm thickness) were obtained by sectioning each tested CAD/CAM block of four materials: a hybrid ceramic (CERASMART™, GC Corporation, Tokyo, Japan), a resin nano ceramic (Lava™ Ultimate, 3M, Monrovia, CA, USA), a nanohybrid composite (Grandio blocs, VOCO GmbH, Cuxhaven, Germany), and a zirconia-reinforced lithium silicate glass ceramic (VITA SUPRINITY® PC; VITA Zahnfabrik, Bad Sackingen, Germany). Forty-five specimens of each material were tested. Micro-hardness was measured at baseline, after 7 days and after 28 days. The data were analyzed. The micro-hardness of each material varied significantly after immersion in Coca-Cola. The nanohybrid composite had a high initial micro-hardness and the greatest percentage loss after acid exposure. The hybrid ceramic and the resin nano ceramic had similar percentage losses of micro-hardness values even if the second material had higher initial values. The zirconia-reinforced lithium silicate glass ceramic had the highest baseline values and the lowest percentage loss of micro-hardness. The different CAD/CAM materials presented different micro-hardness values before and after acid exposure.
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New multi-layered zirconias: Composition, microstructure and translucency. Dent Mater 2019; 35:797-806. [PMID: 30853208 DOI: 10.1016/j.dental.2019.02.017] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 02/13/2019] [Indexed: 11/24/2022]
Abstract
OBJECTIVES To fully realize the range of indication and clinical advantages of the new multi-layered zirconias, a comprehensive understanding of their chemical composition, microstructure, low temperature degradation (LTD) resistance, and translucency properties is paramount. METHODS A zirconia system (Katana, Kuraray Noritake), including 3 distinct grades of multi-layered zirconias, was selected for study: Ultra Translucent Multi-layered zirconia (UTML), Super Translucent Multi-layered zirconia (STML), and Multi-layered zirconia (ML). For different materials and their individual layers, the chemical composition, zirconia phase fractions, and microstructure were determined by X-ray fluorescence (XRF), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). Also, their resistance to LTD and translucency properties were characterized. RESULTS Our findings revealed no major differences amongst layers, but the 3 materials were very distinct-UTML: 5Y-PSZ (5 mol% yttria-partially-stabilized zirconia) with ˜75 wt% cubic content and a 4.05 (±0.85) μm average grain size, STML: 4Y-PSZ with ˜65 wt% cubic content and a 2.81 (±0.17) μm average grain size, and ML: 3Y-PSZ with <50 wt% cubic content and a 0.63 (±0.03) μm average grain size. After water aging at 120 °C for 12 h, greater monoclinic content was found in ML. UTML and STML did not show detectable monoclinic phase. The translucency was similar among layers, and also between UTML and STML, which were superior to ML. SIGNIFICANCE For each multi-layered zirconia grades, the layers are only differed in pigment types and contents, which yield remarkably natural shade gradients. Also, despite the significant compositional difference between STML and UTML, both materials showed similar translucencies.
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Volpato CAM, Carvalho ÓSN, Pereira MRDC, Correia Pereira da Silva FS. Evaluation of the color and translucency of glass-infiltrated zirconia based on the concept of functionally graded materials. J Prosthet Dent 2019; 121:547.e1-547.e7. [PMID: 30661878 DOI: 10.1016/j.prosdent.2018.09.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 09/20/2018] [Accepted: 09/20/2018] [Indexed: 11/26/2022]
Abstract
STATEMENT OF PROBLEM Infiltrated zirconia has promising mechanical properties. However, information about its optical behavior is scarce. PURPOSE The purpose of this in vitro study was to evaluate the color and translucency of zirconia submitted to infiltration and aging. MATERIAL AND METHODS Sixty zirconia disks were machined. Ten disks received no treatment (NT group), 10 disks were immersed in a coloring liquid (A2 group), and 10 disks were immersed in a fluorescent liquid (F group). The other 30 disks were submitted to the same treatments plus glass infiltration (NT+I, A2+I, and F+I groups). The coordinates L*, a*, and b* and the Y tristimulus values were obtained to calculate the color (ΔE00), lightness, chroma, and hue differences; the translucency parameter (TP); and the contrast ratio (CR) associated with the specimens. After aging in an autoclave for 4 hours (T1), new measurements were made. Two- and 3-way ANOVAs were used to analyze color differences, TP, and CR. The lightness, chroma, and hue differences were evaluated by a repeated measures ANOVA. Multiple comparisons were made with the Tukey honestly significant difference (HSD) test (α=.05). RESULTS The greatest color differences were observed in the A2+I group (11.23 ΔE00) (P<.001). Aging affected the chroma of the colored groups (P=.013 and P=.001) but did not affect their translucency (P=.347 for TP and P=.132 for CR). The greatest TP values were found in the NT and NT+I groups (2.54 and 2.34, respectively), whereas the CR was equal to or close to 1 in all groups. CONCLUSIONS Color differences were observed in the glass-infiltrated groups. The TP and CR were affected by infiltration. Aging did not influence the optical behavior of the specimens.
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Affiliation(s)
| | - Óscar Samuel Novais Carvalho
- Assistant Professor, Department of Mechanical Engineering, University of Minho (UMinho), Azurém Campus, Guimarães, Portugal
| | - Mário Rui da Cunha Pereira
- Assistant Professor, Department of Physics, University of Minho (UMinho), Gualtar Campus, Braga, Portugal
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Nam JY, Park MG. Effects of treatment with aqueous and acid-based coloring liquid on the color of zirconia. J Prosthet Dent 2019; 121:363.e1-363.e5. [PMID: 30598311 DOI: 10.1016/j.prosdent.2018.09.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 09/23/2018] [Accepted: 09/24/2018] [Indexed: 11/19/2022]
Abstract
STATEMENT OF PROBLEM To preserve the mechanical property of color-treated zirconia for optimal restoration longevity, aqueous colorants have been developed as an alternative to acid-based coloring agents. However, little is known regarding the effects of aqueous colorants on the color of zirconia. PURPOSE The purpose of this in vitro study was to compare the effect of aqueous coloring liquids with acid-based coloring liquids on the color of zirconia. MATERIAL AND METHODS Eighty monolithic zirconia specimens (10×10×2 mm) were fabricated and divided into 4 groups according to their color treatment: unshaded zirconia (control), precolored zirconia, aqueous coloring liquid on zirconia, and acid-based coloring liquid on zirconia. The shaded zirconia specimens were further divided into 3 subgroups based on the number of coloring applications used (1, 3, or 6). The International Commission on Illumination (CIELab) color coordinates were measured by spectrophotometry. RESULTS Significant differences in the CIE a∗ and b∗ values were observed between the specimen groups treated with the aqueous coloring liquid and the acid-based coloring liquid (P<.001). Increasing the number of colorings resulted in an increase in the CIE a∗ and b∗ values and a decrease in the CIE L∗ values in all the groups (P<.001). CONCLUSIONS Treatment with aqueous coloring liquid on zirconia produced a greater redness or yellowness compared with treatment with acid-based coloring liquid. The coloring of zirconia lowered its brightness and imparted a red/yellow hue.
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Affiliation(s)
- Ji-Young Nam
- Lecturer, Department of Dental Laboratory Science, College of Health Sciences, Catholic University of Pusan, Busan, Republic of Korea
| | - Mi-Gyoung Park
- Associate Professor and Chairman, Department of Dental Laboratory Science, College of Health Sciences, Catholic University of Pusan, Busan, Republic of Korea.
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Song KH, Im YW, Lee JH, Lee J, Lee HH. Evaluation of mold-enclosed shear bond strength between zirconia core and porcelain veneer. Dent Mater J 2018. [PMID: 29515044 DOI: 10.4012/dmj.2017-339] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study aimed to evaluate the mold-enclosed shear bond strength (ME-SBS) of zirconia to veneering porcelain with different surface treatments. Colored or uncolored zirconia coupons were either highly polished or airborne-particle abraded. The specimens were divided into groups with/without application of liner. Veneering porcelain was fired into an alumina ring mold on the zirconia coupons. The assembled specimens were subjected to the ME-SBS test. The mean ME-SBS for groups ranged from 7-10 MPa with no significant difference (p>0.05). A three-way ANOVA showed that coloring and surface roughening of the zirconia specimen had no significant influence on the ME-SBS value, but liner application exhibited a significant effect with a minor decrease in the MESBS (p=0.049). Surface treatments (coloring, airborne-particle abrasion, and liner application) were found to not cause a significant increase to the zirconia-porcelain bond strength. The application of zirconia liner had a slight negative influence on the ME-SBS results.
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Affiliation(s)
- Kwang-Hyun Song
- Department of Prosthodontics, College of Dentistry, Dankook University
| | - Yong-Woon Im
- Department of Biomaterials Science, College of Dentistry, Dankook University.,Department of Dental Laboratory, Kyungdong University
| | - Jung-Hwan Lee
- Department of Biomaterials Science, College of Dentistry, Dankook University.,Institute of Tissue Regeneration Engineering, Dankook University
| | - Jonghyuk Lee
- Department of Prosthodontics, College of Dentistry, Dankook University
| | - Hae-Hyoung Lee
- Department of Biomaterials Science, College of Dentistry, Dankook University.,Institute of Tissue Regeneration Engineering, Dankook University
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Tabatabaian F. Color Aspect of Monolithic Zirconia Restorations: A Review of the Literature. J Prosthodont 2018; 28:276-287. [DOI: 10.1111/jopr.12906] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2018] [Indexed: 02/02/2023] Open
Affiliation(s)
- Farhad Tabatabaian
- Department of Prosthodontics, School of Dentistry; Shahid Beheshti University of Medical Sciences; Tehran Iran
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Subaşı MG, Alp G, Johnston WM, Yilmaz B. Effects of fabrication and shading technique on the color and translucency of new-generation translucent zirconia after coffee thermocycling. J Prosthet Dent 2018; 120:603-608. [PMID: 29807744 DOI: 10.1016/j.prosdent.2018.01.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 01/31/2018] [Accepted: 01/31/2018] [Indexed: 12/17/2022]
Abstract
STATEMENT OF PROBLEM The color stability and translucency of preshaded and externally shaded monolithic and veneered new generation translucent zirconia are not well known. PURPOSE The purpose of this in vitro study was to investigate the effect of fabrication (veneered or monolithic) and shading (preshaded or externally shaded) techniques on the color and relative translucency of translucent zirconia after coffee thermocycling. MATERIAL AND METHODS Specimens of different thicknesses (0.5 mm for veneered and 1.5 mm for monolithic) were sectioned from preshaded and externally shaded translucent zirconia. Externally shaded specimens were colored by using the dipping technique. Externally shaded (Ext Mono) and preshaded (Pre Mono) monolithic zirconia specimens were sintered and glazed. Externally shaded (Ext Vene) and preshaded (Pre Vene) 0.5-mm-thick specimens were sintered, veneered with feldspathic porcelain (1 mm), and glazed. The color coordinates of specimens were measured with a spectroradiometer before and after 10 000 thermocycles in coffee solution. Color differences were calculated using CIEDE2000, and relative translucency parameter (RTP) values were calculated using the RTPCIEDE2000 formula. Analysis of variance (ANOVA) was used to analyze the CIEDE2000 color differences and RTP values (α=.05). RESULTS Shading technique had a significant effect on the color difference values (P=.018). For the translucency data, the 3-way ANOVA revealed a significant interaction between the fabrication technique and shading technique (P=.002). Each pair of material subgroups within each combination of fabrication technique and shading technique was found to have a significantly different RTP, except between Ext Vene and Pre Vene (P=.115). CONCLUSIONS Externally shaded translucent zirconia had a greater color change in coffee than the preshaded translucent zirconia, either in monolithic or veneered form. Fabrication technique significantly affected the RTP, and the monolithic zirconia was more translucent than the veneered zirconia.
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Affiliation(s)
- Meryem Gülce Subaşı
- Assistant Professor, Department of Prosthodontics, Istanbul Aydin University Faculty of Dentistry, Istanbul, Turkey.
| | - Gülce Alp
- Former Visiting Professor, Division of Restorative Sciences and Prosthodontics, College of Dentistry, The Ohio State University; Assistant Professor, Department of Prosthodontics, Okan University Faculty of Dentistry, Istanbul, Turkey
| | - William M Johnston
- Professor Emeritus, Division of General Practice and Materials Science, The Ohio State University College of Dentistry, Columbus, Ohio
| | - Burak Yilmaz
- Associate Professor, Division of Restorative Science and Prosthodontics, The Ohio State University College of Dentistry, Columbus, Ohio
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Mahmood DJH, Braian M, Khan AS, Shabaz A, Larsson C. Fracture load of colored and non-colored high translucent zirconia three-unit fixed dental prosthesis frameworks. ACTA BIOMATERIALIA ODONTOLOGICA SCANDINAVICA 2018; 4:38-43. [PMID: 29707612 PMCID: PMC5917306 DOI: 10.1080/23337931.2018.1459626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 03/28/2018] [Indexed: 11/29/2022]
Abstract
Aim: The use of colored translucent zirconia may enable restorations of a more natural tooth-like appearance than previous opaque white zirconia. The shift from non-colored to colored zirconia may however entail a risk of reduced strength. The aim of the present study was to compare fracture load and fracture mode of fixed dental prostheses frameworks made of colored translucent zirconia to that of non-colored controls. Methods: A total of forty three-unit FDP frameworks were manufactured from two different high translucent zirconia materials (Zenostar, Wieland Dental, and DD cubeX2, Dental Direkt). Each group contained two subgroups, one colored and one non-colored. Coloring was performed before final sintering using two different infiltration techniques. All FDPs underwent an artificial aging process in the form of heat treatment, thermocycling and preloading whereafter the specimens were subjected to load until fracture. Fracture load and mode was registered. Results: For one of the zirconia materials, Zenostar, the non-colored frameworks showed significantly higher fracture loads (p < .0001) compared to its colored counterpart. No significant difference (p > .05) was found between colored and non-colored frameworks in the other zirconia material, DD cubeX2. All FDPs fractured through the connector. Some fractures ran through the mesial and some through the distal side of the connector but there were no significant differences in fracture mode between groups. Conclusion: Coloring before sintering of high-translucent zirconia may decrease the fracture load of FDP frameworks for certain materials and techniques. Fracture mode however, does not appear to be affected.
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Affiliation(s)
| | - Michael Braian
- Department of Prosthetic Dentistry, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - Abdul-Salam Khan
- Department of Prosthetic Dentistry, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - Armin Shabaz
- Department of Prosthetic Dentistry, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - Christel Larsson
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University, Malmö, Sweden
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Alp G, Subaşı MG, Seghi RR, Johnston WM, Yilmaz B. Effect of shading technique and thickness on color stability and translucency of new generation translucent zirconia. J Dent 2018; 73:19-23. [PMID: 29597040 DOI: 10.1016/j.jdent.2018.03.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 03/21/2018] [Accepted: 03/24/2018] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE To evaluate the effect of shading technique and thickness on the color stability and translucency of translucent zirconia after coffee thermocycling. METHODS Specimens in different thicknesses (1; 1.5; 2 mm) (n = 4 for each thickness) were sectioned from translucent preshaded zirconia (Pre) and externally shaded zirconia (Ext). After sintering, specimens were glazed and subjected to 10,000 thermocycling in coffee solution. The color coordinates of specimens were measured with a spectroradiometer before and after coffee thermocyling. Color differences and relative translucency parameter (RTP) values were calculated with CIEDE2000 color difference and TPCIEDE2000 formulas. ANOVA was used to analyze the CIEDE2000 color difference and RTP values (α = 0.05). RESULTS According to 2-way ANOVA, no significant effect of shading technique and thickness on the color difference values was found (P > .05). According to 3-way ANOVA, a significant interaction between the shading technique and thickness (P < .0001) was found for RTP. The RTP parameter decreased with the increase in the thickness. Ext specimens presented significantly higher RTP than Pre specimens (P < .0001), except for between Ext 1 mm and Pre 1 mm (P = .179). CONCLUSIONS Neither shading technique nor tested thicknesses affected the color of translucent zirconia. Shading technique and thickness affected the RTP of translucent zirconia. The RTP was inversely affected with the thickness of the material. Externally shaded zirconia presented higher RTP than preshaded zirconia for specimens thicker than 1 mm. CLINICAL SIGNIFICANCE Discoloration with coffee was insignificant for the tested translucent zirconia in tested thicknesses (1, 1.5, 2 mm). When a translucent restoration is intended, thinner externally shaded translucent zirconia restorations should be preferred instead of preshaded translucent zirconia.
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Affiliation(s)
- Gülce Alp
- Faculty of Dentistry, Department of Prosthodontics, Okan University, Akfirat, Tuzla, 34959, Istanbul, Turkey
| | - Meryem Gülce Subaşı
- Faculty of Dentistry, Department of Prosthodontics, Istanbul Aydin University, Besyol Mah. Akasya Sok., 34295, Istanbul, Turkey
| | - Robert R Seghi
- Division of General Practice and Materials Science, The Ohio State University College of Dentistry, 305 W12th Ave., Columbus, OH 43210, United States
| | - William M Johnston
- Division of General Practice and Materials Science, The Ohio State University College of Dentistry, 305 W12th Ave., Columbus, OH 43210, United States
| | - Burak Yilmaz
- Division of Restorative Science and Prosthodontics, The Ohio State University College of Dentistry, 305 W12th Ave., Columbus, OH 43210, United States.
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Sen N, Sermet IB, Cinar S. Effect of coloring and sintering on the translucency and biaxial strength of monolithic zirconia. J Prosthet Dent 2018; 119:308.e1-308.e7. [DOI: 10.1016/j.prosdent.2017.08.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 08/24/2017] [Accepted: 08/25/2017] [Indexed: 10/18/2022]
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Wille S, Zumstrull P, Kaidas V, Jessen LK, Kern M. Low temperature degradation of single layers of multilayered zirconia in comparison to conventional unshaded zirconia: Phase transformation and flexural strength. J Mech Behav Biomed Mater 2018; 77:171-175. [DOI: 10.1016/j.jmbbm.2017.09.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 09/06/2017] [Indexed: 12/22/2022]
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Silva LHD, Lima ED, Miranda RBDP, Favero SS, Lohbauer U, Cesar PF. Dental ceramics: a review of new materials and processing methods. Braz Oral Res 2017; 31:e58. [PMID: 28902238 DOI: 10.1590/1807-3107bor-2017.vol31.0058] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 05/22/2017] [Indexed: 11/22/2022] Open
Abstract
The evolution of computerized systems for the production of dental restorations associated to the development of novel microstructures for ceramic materials has caused an important change in the clinical workflow for dentists and technicians, as well as in the treatment options offered to patients. New microstructures have also been developed by the industry in order to offer ceramic and composite materials with optimized properties, i.e., good mechanical properties, appropriate wear behavior and acceptable aesthetic characteristics. The objective of this literature review is to discuss the main advantages and disadvantages of the new ceramic systems and processing methods. The manuscript is divided in five parts: I) monolithic zirconia restorations; II) multilayered dental prostheses; III) new glass-ceramics; IV) polymer infiltrated ceramics; and V) novel processing technologies. Dental ceramics and processing technologies have evolved significantly in the past ten years, with most of the evolution being related to new microstructures and CAD-CAM methods. In addition, a trend towards the use of monolithic restorations has changed the way clinicians produce all-ceramic dental prostheses, since the more aesthetic multilayered restorations unfortunately are more prone to chipping or delamination. Composite materials processed via CAD-CAM have become an interesting option, as they have intermediate properties between ceramics and polymers and are more easily milled and polished.
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Affiliation(s)
- Lucas Hian da Silva
- Universidade Cidade de São Paulo - Unicid, School of Dentistry, São Paulo, SP, Brazil
| | - Erick de Lima
- Universidade de São Paulo - USP, School of Dentistry, Department of Biomaterials and Oral Biology, São Paulo, SP, Brazil
| | | | - Stéphanie Soares Favero
- Universidade de São Paulo - USP, School of Dentistry, Department of Biomaterials and Oral Biology, São Paulo, SP, Brazil
| | - Ulrich Lohbauer
- Friedrich-Alexander-Universität Erlangen-Nürnberg - FAU, Dental Clinic 1, Erlangen, Germany
| | - Paulo Francisco Cesar
- Universidade de São Paulo - USP, School of Dentistry, Department of Biomaterials and Oral Biology, São Paulo, SP, Brazil
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Nam JY, Park MG. Effects of aqueous and acid-based coloring liquids on the hardness of zirconia restorations. J Prosthet Dent 2017; 117:662-668. [DOI: 10.1016/j.prosdent.2016.08.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 08/17/2016] [Accepted: 08/17/2016] [Indexed: 11/30/2022]
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Orhun E. The effect of coloring liquid dipping time on the fracture load and color of zirconia ceramics. J Adv Prosthodont 2017; 9:67-73. [PMID: 28243394 PMCID: PMC5321591 DOI: 10.4047/jap.2017.9.1.67] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 08/26/2016] [Accepted: 09/28/2016] [Indexed: 11/08/2022] Open
Abstract
PURPOSE The aims of the study were to evaluate the fracture load of zirconia core material after dipping in coloring liquid at different time intervals and to compare the color of dipped blocks with that of prefabricated shaded blocks. MATERIALS AND METHODS 3-unit bridge frameworks were designed digitally. Sixty frameworks were fabricated using uncolored zirconia blocks by CAD/CAM and divided into 4 groups randomly (n = 15). Group 2 (G2) was subjected to coloring liquids for 2 minutes, Group 4 (G4) for 4 minutes, and Group 6 (G6) for 6 minutes. CFS group was not subjected to any coloring procedure. After coloring, color differences between the test groups and a prefabricated shaded zirconia group (CPZ, n = 15) were evaluated by using a spectrophotometer. Fracture test was conducted immediately after shade evaluation with a Testometric test device at a cross-head speed of 1 mm/sec. Statistical analysis for evaluating color and fracture load was performed by using one way ANOVA followed by Tukey HSD test (P ≤ .05). Weibull analysis was conducted for distribution of fracture load. RESULTS There was no difference in terms of fracture load and color between CFS (1176.681 N) and G2 (985.638 N) group and between CPZ (81.340) and G2 (81.140) group, respectively. Fracture load values of G4 (779.340 N) and G6 (935.491 N) groups were statistically significantly lower than that of CFS group (P ≤ .005). The color values of G4 (79.340) and G6 (79.673) groups were statistically different than that of CPZ group (P ≤ .005). CONCLUSION Prolonged immersion of zirconia in coloring liquid not only negatively affected the fracture load of the zirconia being tested in the current study but also deteriorated the desired shade of the restoration.
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Affiliation(s)
- Ekren Orhun
- Department of Prosthodontics, Faculty of Dentistry, Cukurova University, Adana, Turkey
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Kim HK, Kim SH. Optical properties of pre-colored dental monolithic zirconia ceramics. J Dent 2016; 55:75-81. [DOI: 10.1016/j.jdent.2016.10.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/12/2016] [Accepted: 10/03/2016] [Indexed: 11/29/2022] Open
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Bai Y, Zhao J, Si W, Wang X. Two-body wear performance of dental colored zirconia after different surface treatments. J Prosthet Dent 2016; 116:584-590. [PMID: 27157606 DOI: 10.1016/j.prosdent.2016.02.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 01/31/2016] [Accepted: 02/16/2016] [Indexed: 11/20/2022]
Affiliation(s)
- Yunyang Bai
- Graduate student, Department of Prosthodontics, School and Hospital of Stomatology, Peking University, Beijing, China
| | - Jing Zhao
- Postgraduate student, Department of Prosthodontics, School and Hospital of Stomatology, Peking University, Beijing, China
| | - Wenjie Si
- Associate Professor, Department of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Xinzhi Wang
- Professor, Department of Prosthodontics, School and Hospital of Stomatology, Peking University, Beijing, China.
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Flinn BD, Raigrodski AJ, Mancl LA, Toivola R, Kuykendall T. Influence of aging on flexural strength of translucent zirconia for monolithic restorations. J Prosthet Dent 2016; 117:303-309. [PMID: 27666494 DOI: 10.1016/j.prosdent.2016.06.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 06/14/2016] [Accepted: 06/15/2016] [Indexed: 02/04/2023]
Abstract
STATEMENT OF PROBLEM Concern has been raised with regard to the low-temperature degradation (LTD) of translucent yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) for monolithic zirconia restorations. PURPOSE The purpose of this in vitro study was to assess the LTD behavior of 4 commercially available translucent Y-TZP materials by accelerated aging specimens in steam at 134°C, 0.2 MPa. MATERIAL AND METHODS Thin bars (22×3×0.2 mm) of Y-TZP, including Katana ML (Kuraray Noritake Dental Inc), Katana HT13 (Kuraray Noritake Dental Inc), Prettau (Zirkonzahn), and BruxZir (Glidewell Laboratories) (n=30 for each group), were machined from sintered blocks. Control specimens were assessed in the nonaged condition. Artificially ageing (n=5 per group at 5, 50, 100, 150, and 200 hours) was conducted in steam at 134°C at 0.2 MPa. The specimens were characterized, tested in 4-point flexure, and the fracture surfaces were analyzed. The monoclinic-to-tetragonal (m/t) peak intensity ratio measured by x-ray diffraction was used to calculate the monoclinic phase fraction and monitor LTD. Linear regression with heteroscedasticity-consistent robust standard errors was used to test for the effect of LTD (aging time) on (σf) and m/t. The Spearman rank correlation coefficient was used to assess the relationship between σf and monoclinic phase fraction (α=.05). RESULTS Artificial aging resulted in LTD as shown by an increase in the monoclinic phase fraction for all specimens. After aging for 200 hours, the mean ±SD monoclinic phase fraction increased from 2.90 ±0.34% to 76.1 ±0.64% for Prettau, 2.69 ±0.18% to 76.0 ±0.26% for BruxZir, 4.6 ±0.19% to 35.8 ±0.80% for Katana HT13, and 3.57 ±0.35% to 33.2 ±1.1% for Katana ML (all P<.001). Flexural strength changed from a mean ±SD of 1612 ±197 MPa to all fractured during aging for Prettau (P<.001); 1248 ±73.5 MPa to all fractured during aging for BruxZir (P<.001); 1052 ±84.2 to 1099 ±70 MPa ±130 for Katana HT13 (P=.45); and from 875 ±130 to 909 ±70 MPa (P=.82) for Katana ML. The mean flexural strength values of Prettau and BruxZir decreased with an increase in the monoclinic phase with Spearman rank correlation coefficients of -0.80 (P=.001) for Prettau and -0.63 (P=.022) for BruxZir. No significant changes in flexural strength were measured for Katana ML or Katana HT13 (P>.05). CONCLUSIONS The LTD of Y-TZP resulted in a significant decrease in flexural strength of Prettau and BruxZir, whereas Katana ML and Katana HT13 exhibited less LTD and no significant decrease in flexural strength.
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Affiliation(s)
- Brian D Flinn
- Research Associate Professor, Department of Material Science and Engineering, University of Washington, Seattle, Wash.
| | - Ariel J Raigrodski
- Professor, Department of Restorative Dentistry, School of Dentistry, and Adjunct Professor Department of Materials Science and Engineering, University of Washington, Seattle, Wash
| | - Lloyd A Mancl
- Research Associate Professor, Department of Oral Health Sciences, University of Washington, Seattle, Wash
| | - Ryan Toivola
- Postdoctoral Research Associate, Department of Material Science and Engineering, University of Washington, Seattle, Wash
| | - Tuesday Kuykendall
- Research Engineer, Department of Material Science and Engineering, University of Washington, Seattle, Wash
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