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Ghanem R, Adel A, Al-Zordk W. Effect of simulated intraoral adjustment on the color and translucency of gradient multilayered monolithic zirconia. J Prosthet Dent 2024:S0022-3913(24)00597-3. [PMID: 39332992 DOI: 10.1016/j.prosdent.2024.08.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 08/29/2024] [Accepted: 08/30/2024] [Indexed: 09/29/2024]
Abstract
STATEMENT OF PROBLEM The use of multilayered monolithic zirconia ceramics is becoming popular because it simplifies the production of esthetic restorations. The effect of clinical adjustment on the optical properties of these ceramics, especially strength-gradient zirconia, remains unclear. PURPOSE The purpose of this in vitro study was to evaluate the color and translucency of gradient multilayered zirconia brands after grinding and polishing. MATERIAL AND METHODS Sixty 10×10×1-mm monolithic zirconia specimens were milled from 6 zirconia brands (Ceramill Zolid HT White, Ceramill Zolid HT Preshade, Ceramill Zolid FX Multicolor, VITA YZ XT Multicolor, IPS e.max ZirCAD Prime, and KATANA YML). The zirconia specimens were milled to include all layers of A2 preshaded multilayered zirconia blanks (A2 shade) except Ceramill Zolid HT White and Ceramill Zolid HT Preshade. Ceramill Zolid HT White specimens were milled from a white zirconia blank with subsequent shading. The color coordinates and the relative translucency parameter after glazing and after grinding and polishing were determined with a reflectance spectrophotometer, and the relative translucency parameter and contrast ratio were measured. The differences in color and translucency were calculated. The data were analyzed using 2-way ANOVA and 1-way ANOVA tests followed by the post hoc Tukey test (α=.05). RESULTS Statistically significant changes (P<.001) in the color coordinates measured before and after grinding and polishing were detected for each zirconia brand except for the KATANA YML that showed no significant difference (P=.686) in lightness. The highest color difference after grinding and polishing was detected in group KATANA YML. The 2-way ANOVA test showed a statistically significant interaction (P<.001) between the zirconia brand and the grinding and polishing regarding the relative translucency parameter. The zirconia brand had a significant impact on the relative translucency parameter before and after grinding and polishing (both P<.001). CONCLUSIONS Except for KATANA YML, the color change in multilayered zirconia after clinical adjustment with polishing was not beyond the clinically acceptable limit of the color difference. Although clinical adjustment with polishing reduced the translucency of gradient zirconia, the change in translucency was below the clinically detectable threshold value of the translucency difference.
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Affiliation(s)
- Reham Ghanem
- Graduate student, Department of Fixed Prosthodontics, Mansoura University, Mansoura, Egypt
| | - Ahmed Adel
- Lecturer, Department of Fixed Prosthodontics, Mansoura University, Mansoura, Egypt
| | - Walid Al-Zordk
- Assistant Professor, Department of Fixed Prosthodontics, Mansoura University, Mansoura, Egypt.
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Zaniboni JF, Silva AS, Silva AM, Besegato JF, Muñoz-Chávez OF, de Campos EA. Microstructural and flexural strength of various CAD-CAM lithium disilicate ceramics. J Prosthodont 2024. [PMID: 39233435 DOI: 10.1111/jopr.13938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 08/17/2024] [Indexed: 09/06/2024] Open
Abstract
PURPOSE To analyze the microstructural and mechanical properties of various commercial trademarks of lithium disilicate ceramics for CAD-CAM systems. MATERIALS AND METHODS Specimens of different lithium disilicate ceramics were obtained and randomized into 5 groups (n = 14): EM: e.max CAD; RT: Rosetta SM; EV: Evolith; PM: Smile-Lithium CAD; and, HS: HaHaSmile. The microstructural analysis was performed by X-ray diffraction (XRD) and scanning electron microscopy (SEM); for flexural strength, the three-point bending flexure test was used. XRD and SEM data were qualitatively evaluated. Data from flexural strength were assessed with one-way ANOVA test (α = 0.05) and Weibull analysis. RESULTS High peaks corresponding to the lithium metasilicate and lithium disilicate pattern with similar intensities were observed in all ceramics in the XRD analysis. SEM images showed similar patterns of crystalline structure in the EM and RT ceramics, while the other three groups presented different crystal morphologies than the previous ones and were similar to each other. No differences were found in flexural strength among the groups (p = 0.28). CONCLUSIONS The CAD-CAM lithium disilicate ceramics showed comparable crystalline intensities. The microstructure of the EM and RT ceramics were different from the other groups. Flexural strength was similar among all ceramics.
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Affiliation(s)
- Joissi Ferrari Zaniboni
- Department of Restorative Dentistry, School of Dentistry, Araraquara, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil
- School of Dentistry (FAODO), Federal University of Mato Grosso do Sul (UFMS), Campo Grande, Mato Grosso do Sul, Brazil
| | - Amanda Soares Silva
- Department of Restorative Dentistry, School of Dentistry, Araraquara, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil
| | - Aryvelto Miranda Silva
- Department of Restorative Dentistry, Federal University of Piauí (UFPI), Teresina, Piauí, Brazil
| | - João Felipe Besegato
- School of Dentistry (FAODO), Federal University of Mato Grosso do Sul (UFMS), Campo Grande, Mato Grosso do Sul, Brazil
| | - Oscar Fernando Muñoz-Chávez
- Department of Restorative Dentistry, School of Dentistry, Araraquara, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil
| | - Edson Alves de Campos
- Department of Restorative Dentistry, School of Dentistry, Araraquara, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil
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da Silva BCD, da Silva SEG, da Silva NR, de Moreira FGG, Souza KB, Zhang Y, de Souza ROA. Effect of different surface treatments and adhesive cementation on the surface topography and flexural strength of translucent and ultra-translucent monolithic zirconia. J Prosthodont 2024. [PMID: 39189693 DOI: 10.1111/jopr.13929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Accepted: 07/28/2024] [Indexed: 08/28/2024] Open
Abstract
PURPOSE To evaluate the effect of different surface treatments and adhesive cementation on the miniflexural strength (MFS) of monolithic zirconia. MATERIALS AND METHODS Two-hundred and forty (240) sintered bars of translucent zirconia (ZT) and ultra-translucent zirconia (ZUT) were obtained (8 mm ×2 mm ×1 mm). The bars were divided into 16 groups (n = 15) according to the factors "Zirconia" (ZT and ZUT), "Cementation" (Cem) and "surface treatment" (Ctrl:Control, Al:Aluminum oxide/Al2O3 50 µm, Si:Silica/SiO2 coated alumina particles oxide 30 µm, Gl:Glazing+hydrofluoric acid). Half of the bars received an adhesive layer application, followed by application of resin cement and light curing. The surface roughness was measured in non-cemented groups. All the bars were subjected to the MFS test (1.0 mm/min; 100 kgf). Scanning electron microscopy was used for qualitative analyses. MFS data (MPa) and roughness (µm) were statistically evaluated by three-way and two-way ANOVA respectively and Tukey's test (5%). RESULTS The surface treatment and the interaction were significant for roughness. Glazing promoted less roughness compared to silicatization. Regarding MFS, only the zirconia and surface treatment factors were significant. For ZT, the sandblasted groups had an increase in MFS and glazing reduced it. There was no difference between the groups without cementation for the ZUT; however, ZUT.Si/Cem, and ZUT.Al/Cem obtained superior MFS among the cemented groups. CONCLUSIONS Sandblasting increases the flexural strength for ZT, while glaze application tends to reduce it. Applying resin cement increases the flexural strength of ZUT when associated with sandblasting. Sandblasting protocols promote greater surface roughness.
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Affiliation(s)
| | - Sarah Emille Gomes da Silva
- Department of Dentistry, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
| | - Nathália Ramos da Silva
- Department of Dentistry, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
| | | | - Karina Barbosa Souza
- Institute of Science and Technology, Paulista State University (UNESP), São José dos Campos, São Paulo, Brazil
| | - Yu Zhang
- Department of Preventive and Restorative, University of Pennsylvania, School of Dental Medicine, Philadelphia, USA
| | - Rodrigo Othávio Assunção de Souza
- Department of Dentistry, Adjunct Professor in Prosthodontics, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
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Bawazir M, Lim C, Arnés-Urgellés P, Lu M, Huang H, Zhang Y. Brittle-Ductile Threshold in Lithium Disilicate under Sharp Sliding Contact. J Dent Res 2024; 103:839-847. [PMID: 38877734 PMCID: PMC11307199 DOI: 10.1177/00220345241256279] [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] [Indexed: 06/16/2024] Open
Abstract
Computer-aided design (CAD)/computer-aided manufacturing (CAM) milling and handpiece grinding are critical procedures in the fabrication and adjustment of ceramic dental restorations. However, due to the formation of microfractures, these procedures are detrimental to the strength of ceramics. This study analyzes the damage associated with current brittle-regime grinding and presents a potential remedy in the application of a safer yet still efficient grinding regime known as "ductile-regime grinding." Disc-shaped specimens of a lithium disilicate glass-ceramic material (IPS e.max CAD) were obtained by cutting and crystallizing the lithium metasilicate CAD/CAM blanks (the so-called blue blocks) following the manufacturer's instructions. The discs were then polished to a 1 µm diamond suspension finish. Single-particle micro-scratch tests (n = 10) with a conical diamond indenter were conducted to reproduce basic modes of deformation and fracture. Key parameters such as coefficient of friction and penetration depth were recorded as a function of scratch load. Further, biaxial flexure strength tests (n = 6) were performed after applying various scratch loads to analyze their effects on ceramic strength. Scanning electron microscopy (SEM) and focused ion beam (FIB) were used to characterize surface and subsurface damage. Statistical analysis was performed using one-way analysis of variance and Tukey tests. While the SEM surface analysis of scratch tracks revealed the occurrence of both ductile and brittle removal modes, it failed to accurately determine the threshold load for the brittle-ductile transition. The threshold load for brittle-ductile transition was determined to be 70 mN based on FIB subsurface damage analyses in conjunction with strength degradation studies. Below 70 mN, the specimens exhibited neither strength degradation nor the formation of subsurface cracks. Determination of the brittle-ductile thresholds is significant because it sets a foundation for future research on the feasibility of implementing ductile-regime milling/grinding protocols for fabricating damage-free ceramic dental restorations.
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Affiliation(s)
- M. Bawazir
- Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Restorative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - C.H. Lim
- Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - P. Arnés-Urgellés
- School of Mechanical and Mining Engineering, The University of Queensland, St Lucia, QLD, Australia
| | - M. Lu
- School of Mechanical and Mining Engineering, The University of Queensland, St Lucia, QLD, Australia
| | - H. Huang
- School of Mechanical and Mining Engineering, The University of Queensland, St Lucia, QLD, Australia
- School of Advanced Manufacturing, Sun Yat-sen University (Shenzhen Campus), China
| | - Y. Zhang
- Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Wang J, Yang L. Clinical application principles and new developments of zirconia crown. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2024; 42:135-141. [PMID: 38597073 PMCID: PMC11034402 DOI: 10.7518/hxkq.2024.2023404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/09/2024] [Indexed: 04/11/2024]
Abstract
Zirconia crown has been widely used in the field of prosthodontics. Traditional zirconia exhibits excellent mechanical properties but lacks translucency. The introduction of transparent zirconia significantly enhances its aesthetic performance. In clinical applications, factors affecting the aesthetic results of full zirconia crown should be comprehensively considered, and the most suitable restoration should be chosen. Additionally, clinicians need to design appropriate tooth preparation dimensions and methods based on an individual patient's actual situation. During the clinical bonding process of zirconia, proper surface treatment of the tooth and restoration is essential. The selection of suitable adhesives is crucial for achieving optimal bonding strength and aesthetics.
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Affiliation(s)
- Jian Wang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China Supported by: National Key R&D Program of China (2022YFC2410103)
| | - Linxin Yang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China Supported by: National Key R&D Program of China (2022YFC2410103)
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Albani R, Habib SR, AlQahtani A, AlHelal AA, Alrabiah M, Anwar S. The Surface Roughness of Contemporary Indirect CAD/CAM Restorative Materials That Are Glazed and Chair-Side-Finished/Polished. MATERIALS (BASEL, SWITZERLAND) 2024; 17:997. [PMID: 38473470 DOI: 10.3390/ma17050997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/11/2024] [Accepted: 02/14/2024] [Indexed: 03/14/2024]
Abstract
The surface roughness (Ra) of indirect computer-aided design/computer-aided manufacturing (CAD/CAM)-fabricated dental restorations is crucial for their long-term durability. This study intended to evaluate the Ra of five different types of contemporary indirect CAD/CAM restorative materials with varying compositions that were glazed and finished/polished. A total of 75 specimens, disc-shaped (10 mm × 2 mm), were obtained from five materials (n = 15) (Tetric CAD, IPS e.max CAD, IPS e.max ZirCAD, CELTRA Duo, and Vita Enamic) and fabricated by CAD/CAM. One of the two surfaces for each specimen was subjected to glazing, while the other surface was subjected to finishing/polishing. The Ra of the two surfaces in micrometers (μm) was evaluated using a Profilometer, while the surface topography was examined using a scanning electron microscope. Using SPSS, the Kruskal-Wallis, post hoc Conover, and Mann-Whitney tests were used to statistically evaluate the data. A comparison of the Ra for the finished/polished surfaces of the five test materials showed significant differences (p < 0.0001). Among the finished/polished surfaces, the mean rank values of Vita Enamic were significantly higher than the other four test materials (p < 0.0001). A comparison of the Ra of glazed surfaces among the five study materials revealed significant differences (p < 0.0001). The Ra for the IPS e.max ZirCAD material was significantly higher than the rest of the four materials (p < 0.001). A comparison of the Ra for two types of surface conditioning within each of the five test materials showed a significant difference (p < 0.05). Only for IPS e.max ZirCAD was the Ra of the glazed surface significantly higher than the finished/polished surface (p < 0.0001). Significant variations in the surface roughness (Ra) were exhibited between the finished/polished and glazed surfaces of the five test materials. Hybrid ceramics showed the highest Ra values for the finished/polished surfaces, and zirconia exhibited the highest Ra values among the glazed surfaces among the tested materials. The Ra values of either finished/polished or glazed surfaces of the test materials were within the clinically acceptable range (0.2-0.5 μm), except for the glazed surface of the zirconia ceramics (0.84 μm).
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Affiliation(s)
- Ragad Albani
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia
| | - Syed Rashid Habib
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia
| | - Abdulaziz AlQahtani
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia
| | - Abdulaziz A AlHelal
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia
| | - Mohammed Alrabiah
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia
| | - Saqib Anwar
- Industrial Engineering Department, College of Engineering, King Saud University, Riyadh 11545, Saudi Arabia
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Dokuzlu SN, Subaşı MG. Effect of sintering programs and surface treatments on monolithic zirconia. J Adv Prosthodont 2024; 16:25-37. [PMID: 38455679 PMCID: PMC10917628 DOI: 10.4047/jap.2024.16.1.25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 01/28/2024] [Accepted: 02/13/2024] [Indexed: 03/09/2024] Open
Abstract
PURPOSE To investigate the effect of sintering programs and surface treatments on surface properties, phase transformation and flexural strength of monolithic zirconia. MATERIALS AND METHODS Zirconia specimens were sintered using three distinct sintering programs [classic (C), speed (S), and superspeed (SS)] (n = 56, each). One sample from each group underwent scanning electron microscopy (SEM) and grain size analysis following sintering. Remaining samples were divided into five subgroups (n = 11) based on the surface treatments: control (CL), polish (P), glaze (G), grind + polish (GP), and grind + glaze (GG). One sample from each subgroup underwent SEM analysis. Remaining samples were thermally aged. Monoclinic phase volume, surface roughness, and three-point flexural strength were measured. Monoclinic phase volume and surface roughness were analyzed by Kruskal-Wallis and Dunn tests. Flexural strength was analyzed by two-way ANOVA and Weibull analysis. The relationships among the groups were analyzed using Spearman's correlation analysis. RESULTS Sintering program, surface treatment, and sintering × surface treatment (P ≤ .010) affected the monoclinic phase volume, whereas the type of surface treatment and sintering × surface treatment affected the surface roughness (P < .001). Type of sintering program or surface treatment did not affect the flexural strength. Weibull analysis revealed no significant differences between the m and σo values. Monoclinic phase volume was positively correlated with surface roughness in the SGG and SSP groups. CONCLUSION After sintering monolithic zirconia in each of the three sintering programs, each of the surface treatments can be used. However, for surface quality and aging resistance, G or GG can be recommended as a surface finishing method.
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Affiliation(s)
| | - Meryem Gülce Subaşı
- Department of Prosthodontics, Faculty of Dentistry, Kütahya Sağlık Bilimleri University, Kütahya, Turkey
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Chopra D, Guo T, Gulati K, Ivanovski S. Load, unload and repeat: Understanding the mechanical characteristics of zirconia in dentistry. Dent Mater 2024; 40:e1-e17. [PMID: 37891132 DOI: 10.1016/j.dental.2023.10.007] [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: 01/25/2023] [Revised: 09/11/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023]
Abstract
OBJECTIVES Zirconia-based dental restorations and implants are gaining attention due to their bioactivity, corrosion resistance and mechanical stability. Further, surface modification of zirconia implants has been performed at the macro-, micro- and nanoscale to augment bioactivity. While zirconia's physical and chemical characteristics have been documented, its relation to mechanical performance still needs to be explored. This extensive review aims to address this knowledge gap. METHODS This review critically compares and contrasts the findings from articles published in the domain of 'mechanical stability of zirconia\ in dentistry' based on a literature survey (Web of Science, Medline/PubMed and Scopus databases) and a review of the relevant publications in international peer-reviewed journals. Reviewing the published data, the mechanical properties of zirconia, such as fracture resistance, stress/tension, flexural strength, fatigue, and wear are detailed and discussed to understand the biomechanical compatibility of zirconia with the mechanical performance of modified zirconia in dentistry also explored. RESULTS A comprehensive insight into dental zirconia's critical fundamental mechanical characteristics and performance is presented. Further, research challenges and future directions in this domain are recommended. SIGNIFICANCE This review extends existing knowledge of zirconia's biomechanical performance and it they can be modulated to design the next generation of zirconia dental restorations and implants to withstand long-term constant loading.
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Affiliation(s)
- Divya Chopra
- The University of Queensland, School of Dentistry, Herston, QLD 4006, Australia; Centre for Orofacial Regeneration, Reconstruction and Rehabilitation (COR3), Herston, QLD 4006, Australia
| | - Tianqi Guo
- The University of Queensland, School of Dentistry, Herston, QLD 4006, Australia; Centre for Orofacial Regeneration, Reconstruction and Rehabilitation (COR3), Herston, QLD 4006, Australia
| | - Karan Gulati
- The University of Queensland, School of Dentistry, Herston, QLD 4006, Australia; Centre for Orofacial Regeneration, Reconstruction and Rehabilitation (COR3), Herston, QLD 4006, Australia.
| | - Sašo Ivanovski
- The University of Queensland, School of Dentistry, Herston, QLD 4006, Australia; Centre for Orofacial Regeneration, Reconstruction and Rehabilitation (COR3), Herston, QLD 4006, Australia.
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Kwon WC, Park MG. Evaluation of mechanical properties of dental zirconia in different milling conditions and sintering temperatures. J Prosthet Dent 2023; 130:909-916. [PMID: 35115161 DOI: 10.1016/j.prosdent.2021.12.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 12/08/2021] [Accepted: 12/08/2021] [Indexed: 11/30/2022]
Abstract
STATEMENT OF PROBLEM The dry processing of zirconia has the disadvantage of dust dispersal during milling; thus, wet milling may be preferable. However, research on the mechanical properties of dental zirconia milled under different conditions and sintered at different temperatures is lacking. PURPOSE The purpose of this in vitro study was to evaluate changes in the mechanical properties of zirconia specimens after milling under dry and wet conditions at different sintering temperatures. MATERIAL AND METHODS Four hundred Ø20.0×1.5-mm presintered zirconia specimens were prepared by using a computer-aided design and computer-aided manufacturing (CAD-CAM) system and divided into 8 groups (n=50) based on the sintering (1230, 1330, 1430, and 1530 °C) and milling conditions (dry or wet). The mechanical properties (Vickers hardness, biaxial flexural strength, and fracture toughness) and physical properties (linear shrinkage and density) were examined. The microstructures of the specimens were observed with a scanning electron microscope. The crystal phases of the sintered green bodies were analyzed by using an X-ray diffractometer. The data were analyzed with descriptive statistics and 1-way and 2-way analyses of variance with Tukey HSD tests (α=.05). RESULTS The mechanical properties of all specimens increased with increasing sintering temperature, except for 1530 °C and the dry milling condition. The mechanical properties of the groups fabricated under wet milling conditions were better than those of the groups fabricated under dry milling conditions. Microscopic examination of the structure showed that the porosity decreased with increasing sintering temperature regardless of the milling conditions. CONCLUSIONS Higher sintering temperatures increased the mechanical properties (biaxial flexural strength, Vickers hardness, fracture toughness). However, phase transformation from tetragonal to cubic was observed for dry milled specimens sintered at 1530 °C, with decreased mechanical properties. Specimens fabricated by wet milling exhibited better mechanical properties than those fabricated by dry milling.
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Affiliation(s)
- Woo-Chang Kwon
- Interdisciplinary, Department for Advanced Innovative Manufacturing Engineering, Pusan National University, Busan, Republic of Korea
| | - Mi-Gyoung Park
- Professor and Chairman, Department of Dental Laboratory Science, College of Health Sciences, Catholic University of Pusan, Busan, Republic of Korea.
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Giti R, Jebal R. How could mouthwashes affect the color stability and translucency of various types of monolithic zirconia? An in-vitro study. PLoS One 2023; 18:e0295420. [PMID: 38039318 PMCID: PMC10691725 DOI: 10.1371/journal.pone.0295420] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 11/20/2023] [Indexed: 12/03/2023] Open
Abstract
OBJECTIVES This study aimed to evaluate the color stability and translucency of various types of monolithic zirconia after immersion in chlorhexidine and Listerine mouthwashes. MATERIALS AND METHODS This experimental study was performed on 36 disk-shaped specimens fabricated from low-translucent, high-translucent, and multilayered monolithic zirconia (n = 12 per group). Each group was equally divided and immersed in either 2% chlorhexidine (CHX) or Listerine mouthwash for 2 min daily over 7 days. Changes in color (ΔE) and the translucency parameter (ΔTP) were evaluated and compared. The data were analyzed with one-way ANOVA followed by Tukey's post-hoc tests (α = 0.05). RESULTS Chlorhexidine caused a significantly lower ΔE and a significantly higher ΔTP in multilayered zirconia compared to the low-translucency (ΔE: P = 0.0027, ΔTP: P<0.001) and the high-translucency zirconia group (ΔE: P<0.001, ΔTP: P = 0.022). Listerine caused a significantly higher ΔE in the high-translucency zirconia group compared to the multilayered zirconia group (P = 0.0165). It also resulted in a significantly higher mean ΔTP in the multilayered zirconia group compared to the low-translucency (P = 0.0003) and high-translucency zirconia groups (P = 0.019). CONCLUSIONS In both mouthwashes, multilayered monolithic zirconia exhibited the highest color stability among the tested materials; albeit with the most pronounced changes in translucency. Meanwhile, high-translucency monolithic zirconia was more prone to discoloration when exposed to both mouthwashes.
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Affiliation(s)
- Rashin Giti
- Department of Prosthodontics, Faculty of Dentistry, Shiraz University of Medical Sciences, Shiraz, Fars, Iran
| | - Reza Jebal
- Student Research Committee, Faculty of Dentistry, Shiraz University of Medical Sciences, Shiraz, Fars, Iran
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Silva NR, Araújo GD, Moura D, Araújo LD, Gurgel BDV, Melo RM, Bottino MA, Özcan M, Zhang Y, Souza R. Clinical Performance of Minimally Invasive Monolithic Ultratranslucent Zirconia Veneers: A Case Series up to Five Years of Follow-up. Oper Dent 2023; 48:606-617. [PMID: 37961016 DOI: 10.2341/22-118-t] [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: 08/05/2023] [Indexed: 11/15/2023]
Abstract
There is a lack of reports in the literature on the long-term clinical performance of ultratranslucent zirconia, especially considering its use in manufacturing monolithic veneers. The purpose of this case series is to describe the aesthetic treatment steps of three patients with minimally invasive ultratranslucent zirconia veneers and to report the clinical findings up to five years. Three patients (woman: 2, man: 1; mean age: 30 years) unsatisfied with their dental aesthetics sought dental treatment. The treatment plan involved cementing ultratranslucent zirconia veneers. Air-abrasion was performed on the internal surface of zirconia with alumina particles coated by silica (silicatization), followed by silane and adhesive applications for the adhesive cementation. All veneers were adhesively cemented to enamel with resin cement (Variolink Esthetic, Ivoclar). The patients were clinically evaluated annually considering the Ryge modified/ California Dental Association criteria. After a mean follow-up of 4.33 years (4-5 years), a survival rate of 100% was detected for the 28 minimally invasive ultratranslucent zirconia veneers cemented in the 3 patients. There were no absolute failures such as debonding, veneer fracture, or secondary caries. Superficial marginal discoloration was observed in one element (maxillary left lateral incisor) of one patient. Ultratranslucent zirconia is a viable option for manufacturing veneers due to its excellent clinical performance and longevity. However, further long-term clinical studies are essential to consolidate this material as an option for esthetic restorations.
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Affiliation(s)
- N R Silva
- Nathalia Ramos Silva, DDs, MSc, PhD, Federal University of Rio Grande do Norte (UFRN), Brazil
| | - Gm de Araújo
- Gabriela Monteiro de Araújo, DDs, MSc, PhD, Federal University of Rio Grande do Norte (UFRN), Brazil
| | - Dmd Moura
- Dayanne Monteiro Duarte Moura, DDS, MSc, PhD, professor, State University of Rio Grande do Norte (UERN), Brazil
| | - Lnm de Araújo
- Lidya Nara Marques de Araújo, DDs, MSc, PhD, Federal University of Rio Grande do Norte (UFRN), Brazil
| | - Bc de Vasconcelos Gurgel
- Bruno César de Vasconcelos Gurgel, DDs, MSc, PhD, professor, Federal University of Rio Grande do Norte (UFRN), Brazil
| | - R M Melo
- Renata Marques Melo, DDS, MSc, PhD, professor, São Paulo State University (UNESP/SJP), Brazil
| | - M A Bottino
- Marco Antonio Bottino, DDs, MSc, PhD, professor, São Paulo State University (UNESP/SJP), Brazil
| | - M Özcan
- Mutlu Özcan, DDs, MSc, PhD, professor, University of Zurich, Switzerland
| | - Y Zhang
- Yu Zhang, DDs, MSc, PhD, professor, University of Pennsylvania, Philadelphia, PA
| | - Roa Souza
- *Rodrigo Othavio Assunção Souza, DDS, MSc, PhD, professor, Federal University of Rio Grande do Norte (UFRN), Brazil
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12
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Salah K, Sherif AH, Mandour MH, Nossair SA. Optical effect of rapid sintering protocols on different types of zirconia. J Prosthet Dent 2023; 130:253.e1-253.e7. [PMID: 37330359 DOI: 10.1016/j.prosdent.2023.05.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 05/07/2023] [Accepted: 05/09/2023] [Indexed: 06/19/2023]
Abstract
STATEMENT OF PROBLEM Rapid sintering protocols are available for the fabrication of zirconia restorations, but whether rapid sintering influences color or translucency is unclear. PURPOSE The purpose of this in vitro study was to investigate the effect of different rapid sintering protocols on the color and translucency of cubic and tetragonal zirconias. MATERIAL AND METHODS Sixty disk-shaped specimens of 1-mm-thick cubic (DD CubeX2) and tetragonal (DD Bio ZX2) zirconia were investigated. Specimens of each type of zirconia were divided into three groups: conventional, speed, and superspeed sintering protocols. The conventional group of each zirconia type served as the control for calculating color differences. Translucency for each group was assessed by the translucency parameter and contrast ratio. Two-way analysis of variance was used for statistical analysis of the data (α=.05). RESULTS The translucency of cubic and tetragonal zirconia decreased after speed and superspeed sintering (P<.001). Superspeed sintering resulted in a greater color change than speed sintering (P<.001). CONCLUSIONS Rapid sintering protocols produced a significant effect on the color and translucency of cubic and tetragonal zirconias.
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Affiliation(s)
- Kerolos Salah
- Former Postgraduate student, Department of Fixed Prosthodontics, Faculty of Oral and Dental Medicine, Future University, New Cairo, Egypt.
| | - Ashraf Hussein Sherif
- Professor, Department of Fixed Prosthodontics, Faculty of Oral and Dental Medicine, Future University, New Cairo, Egypt
| | - Mona H Mandour
- Professor, Department of Crown and Bridge, Faculty of Dental Medicine, Al-Azhar University, Girls' Branch, Cairo, Egypt
| | - Shereen Ahmed Nossair
- Assistant Professor, Department of Fixed Prosthodontics, Faculty of Oral and Dental Medicine, Future University, New Cairo, Egypt
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13
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Elkady AAM, Ameen SA, Sami RN. Intraoral occlusal adjustment time and volume required for CAD/CAM crowns fabricated with different virtual mounting methods (A randomized crossover trial). BDJ Open 2023; 9:19. [PMID: 37164989 PMCID: PMC10172387 DOI: 10.1038/s41405-023-00146-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 04/02/2023] [Accepted: 04/14/2023] [Indexed: 05/12/2023] Open
Abstract
OBJECTIVE To measure the required clinical time and volume of occlusal adjustment when the maxillary cast is positioned in a virtual articulator using one of three methods: digitization of a facebow-mounted mechanical articulator (group A), virtual Bonwill triangle (group B) or a 3D face scan (group F). MATERIALS AND METHODS In this randomized, triple-blind, crossover trial; 11 participants were enrolled. Every participant had one molar indicated for a single crown restoration. Three crowns were designed and milled for every participant molar totaling 33 crowns. Each of the three crowns was fabricated with the participant's casts virtually mounted utilizing a different method. An impression was taken of the crown in place before occlusal adjustment. The occlusal adjustment was then performed and timed with the three crowns in the different groups. After the occlusal adjustment, an impression of the adjusted crown was taken. The pre-adjustment and post-adjustment impressions were digitally superimposed and the volume difference was measured. The Kruskal-Wallis test was used to compare the groups. RESULTS Group A showed the shortest mean adjustment time (3:44.59 ± 3:39.07) followed by group F (4:30.09 ± 2:01.50) and group B (4:35.30 ± 2:32.33). The mean adjustment volume for group A was (28 ± 19.1 mm3) followed by group F (30.5 ± 18.8 mm3) and group B (40.6 ± 29.5 mm3). Different virtual mounting methods had no statistically significant effect on adjustment time (P-value = 0.538) or adjustment volume (P-value = 0.490). CONCLUSIONS A simplified approach in virtual articulator mounting appears to be justified in the construction of a single full-coverage prosthesis. Added labor, time and cost of more elaborate virtual mounting methods seem to be counterproductive.
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Affiliation(s)
| | - Shereen Adel Ameen
- Fixed Prosthodontics Department and Vice Dean for Community Service and Environmental Development, Faculty of Dentistry, Cairo University, Cairo, Egypt
| | - Rasha Nabil Sami
- Fixed Prosthodontics Department, Faculty of Dentistry, Cairo University, Cairo, Egypt
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14
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Ribeiro AKC, de Freitas RFCP, de Carvalho IHG, de Miranda LM, da Silva NR, de Fátima Dantas de Almeida L, Zhang Y, da Fonte Porto Carreiro A, de Assunção E Souza RO. Flexural strength, surface roughness, micro-CT analysis, and microbiological adhesion of a 3D-printed temporary crown material. Clin Oral Investig 2023; 27:2207-2220. [PMID: 36933047 PMCID: PMC10164099 DOI: 10.1007/s00784-023-04941-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 03/05/2023] [Indexed: 03/19/2023]
Abstract
OBJECTIVE To evaluate the thermocycling effect of 3D-printed resins on flexural strength, surface roughness, microbiological adhesion, and porosity. MATERIALS AND METHODS 150 bars (8 × 2 × 2 mm) and 100 blocks (8 × 8 × 2 mm) were made and divided into 5 groups, according to two factors: "material" (AR: acrylic resin, CR: composite resin, BIS: bis-acryl resin, CAD: CAD/CAM resin, and PRINT: 3D-printed resin) and "aging" (non-aged and aged - TC). Half of them were subjected to thermocycling (10,000 cycles). The bars were subjected to mini-flexural strength (σ) test (1 mm/min). All the blocks were subjected to roughness analysis (Ra/Rq/Rz). The non-aged blocks were subjected to porosity analysis (micro-CT; n = 5) and fungal adherence (n = 10). Data were statistically analyzed (one-way ANOVA, two-way ANOVA; Tukey's test, α = 0.05). RESULTS For σ, "material" and "aging" factors were statistically significant (p < 0.0001). The BIS (118.23 ± 16.26A) presented a higher σ and the PRINT group (49.87 ± 7.55E) had the lowest mean σ. All groups showed a decrease in σ after TC, except for PRINT. The CRTC showed the lowest Weibull modulus. The AR showed higher roughness than BIS. Porosity revealed that the AR (1.369%) and BIS (6.339%) presented the highest porosity, and the CAD (0.002%) had the lowest porosity. Cell adhesion was significantly different between the CR (6.81) and CAD (6.37). CONCLUSION Thermocycling reduced the flexural strength of most provisional materials, except for 3D-printed resin. However, it did not influence the surface roughness. The CR showed higher microbiological adherence than CAD group. The BIS group reached the highest porosity while the CAD group had the lowest values. CLINICAL RELEVANCE 3D-printed resins are promising materials for clinical applications because they have good mechanical properties and low fungal adhesion.
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Affiliation(s)
- Anne Kaline Claudino Ribeiro
- Department of Dentistry, Grande Do Norte (UFRN), Federal University of Rio, Av. Salgado FilhoLagoa Nova, Natal, RN, CEP, 178759056-000, Brazil
| | | | - Isabelle Helena Gurgel de Carvalho
- Department of Dentistry, Grande Do Norte (UFRN), Federal University of Rio, Av. Salgado FilhoLagoa Nova, Natal, RN, CEP, 178759056-000, Brazil
| | - Larissa Mendonça de Miranda
- Department of Dentistry, Grande Do Norte (UFRN), Federal University of Rio, Av. Salgado FilhoLagoa Nova, Natal, RN, CEP, 178759056-000, Brazil
| | - Nathália Ramos da Silva
- Department of Dentistry, Grande Do Norte (UFRN), Federal University of Rio, Av. Salgado FilhoLagoa Nova, Natal, RN, CEP, 178759056-000, Brazil
| | - Leopoldina de Fátima Dantas de Almeida
- Department of Clinical and Social Dentistry, Health Science Center, Cidade Universitária, Federal University of Paraíba (UFPB), João Pessoa, PB, CEP, 58051-900, Brazil
| | - Yu Zhang
- School of Dental Medicine, Department of Preventive and Restorative Sciences, University of Pennsylvania, Philadelphia, PA, USA
| | - Adriana da Fonte Porto Carreiro
- Department of Dentistry, Grande Do Norte (UFRN), Federal University of Rio, Av. Salgado FilhoLagoa Nova, Natal, RN, CEP, 178759056-000, Brazil
| | - Rodrigo Othávio de Assunção E Souza
- Department of Dentistry, Grande Do Norte (UFRN), Federal University of Rio, Av. Salgado FilhoLagoa Nova, Natal, RN, CEP, 178759056-000, Brazil.
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Abstract
The purpose of this article is to review current understanding of lithia-based glass-ceramics and to identify future research needs for this class of dental materials in relation to novel compositions and fabrication methods. With rapid advances in material development and digital technology, time efficiency of dental workflow and fit accuracy of ceramic restorations are ever improving. Lithia-based glass-ceramics are at the forefront of this advance-new variants with more efficient fabrication routes are continually being introduced into the marketplace. Base glass composition, crystallization heat treatment, nucleant and coloration additives, and property gradation are some pertinent variables. The trend in fabrication is to move from CAD/CAM grinding of partially crystallized glass-ceramics to fully crystallized materials, thereby circumventing the need for postmachining firing altogether. In these endeavors, a better understanding of mechanical properties and evolving shaping technologies, such as ductile grinding, is paramount. Additive manufacturing and 3-dimensional printing methodologies offer a promising alternative to current CAD/CAM subtractive manufacturing routes. Challenges to the implementation of new technologies in efficient development and production of high-quality dental glass-ceramic prostheses are addressed.
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Affiliation(s)
- Y. Zhang
- Department of Preventive and
Restorative Sciences, School of Dental Medicine, University of Pennsylvania,
Philadelphia, PA, USA
| | - S. Vardhaman
- Department of Preventive and
Restorative Sciences, School of Dental Medicine, University of Pennsylvania,
Philadelphia, PA, USA
| | - C.S. Rodrigues
- Department of Dental Materials and
Prosthodontics, Institute of Science and Technology, São Paulo State University, São
José dos Campos, Brazil
| | - B.R. Lawn
- Material Measurement Laboratory,
National Institute of Standards and Technology, Gaithersburg, MD, USA
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16
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da Rosa LS, Pilecco RO, Sarkis-Onofre R, Kantorski KZ, Valandro LF, Rocha Pereira GK. Should finishing, polishing or glazing be performed after grinding YSZ ceramics? A systematic review and meta-analysis. J Mech Behav Biomed Mater 2023; 138:105654. [PMID: 36634437 DOI: 10.1016/j.jmbbm.2023.105654] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/26/2022] [Accepted: 01/01/2023] [Indexed: 01/04/2023]
Abstract
The present systematic review and meta-analysis aimed to assess the characteristics and consequences of post-processing methods after grinding procedures in YSZ ceramics on its surface roughness and flexural strength. The protocol of this review was made prospectively and is available online in the PROSPERO database (link). Literature searches on PubMed/MEDLINE, EMBASE, Lilacs, Web of Science and Scopus were conducted on December 2022 to select in vitro studies written in English, without publishing-date restrictions, that considered surface characteristics and mechanical properties of YSZ ceramics submitted to grinding and subsequent post-processing surface treatments as an attempt to revert the effect induced by grinding. Two authors independently selected the studies, extracted the data and assessed the risk of bias. Mean differences (Rev-Man 5.1, random effects model, α= 0.05) were obtained by comparing flexural strength and surface roughness values of ground surfaces with at least one post-processing surface treatment (global analysis). Subgroup analyses were performed considering the most prevalent categories of post-processing methods. A total of 33 (out of 4032) studies were eligible and included in the analysis. In the global analysis, ground surfaces showed higher flexural strength than when post-processing methodologies were employed (p< 0.0001). The subgroup analysis showed that only polishing was able to enhance the flexural strength after grinding (p= 0.001); however, when other protocols were used, the ground surface was always superior in terms of flexural strength (p< 0.0001). Post-processing techniques in both the global and sub-group analyses were able to reduce the surface roughness after grinding in YSZ ceramics (p< 0.00001). High heterogeneity was found in all the meta-analyses. Concerning the risk of bias analysis, the included studies had mixed scores for the considered factors. In conclusion, in terms of improving flexural strength and restoring surface roughness after grinding, polishing protocols can be considered the best indication as post-processing treatment after YSZ ceramics adjustments/grinding.
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Affiliation(s)
- Lucas Saldanha da Rosa
- MSciD and PhD Post-Graduate Program in Oral Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
| | - Rafaela Oliveira Pilecco
- MSciD and PhD Post-Graduate Program in Oral Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
| | - Rafael Sarkis-Onofre
- Graduate Program in Dentistry, Atitus Educação, Passo Fundo, Rio Grande do Sul, Brazil.
| | - Karla Zanini Kantorski
- MSciD and PhD Post-Graduate Program in Oral Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
| | - Luiz Felipe Valandro
- MSciD and PhD Post-Graduate Program in Oral Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
| | - Gabriel Kalil Rocha Pereira
- MSciD and PhD Post-Graduate Program in Oral Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
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17
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da Silva SEG, de Araújo GM, Souza KB, Moura DMD, Aurélio IL, May LG, Vila-Nova TEL, Zhang Y, de Assunção E Souza RO. Biaxial flexure strength and physicochemical characterization of a CAD/CAM lithium disilicate ceramic: effect of etching time, silane, and adhesive applications. Clin Oral Investig 2022; 26:6753-6763. [PMID: 35980474 PMCID: PMC9902029 DOI: 10.1007/s00784-022-04635-2] [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: 03/07/2022] [Accepted: 07/12/2022] [Indexed: 01/21/2023]
Abstract
OBJECTIVE To evaluate the effect of different acid etching time and bonding agent (silane and/or adhesive system) on biaxial flexural strength and physico-chemical properties of a lithium disilicate ceramic. MATERIAL AND METHODS One hundred twenty ceramic discs were made and divided into 8 groups (n = 15) according to factors "etching time" (20 and 120 s) with hydrofluoric acid (HF) and "bonding agent" (C, no bonding agent; S, silane, A, adhesive; and SA, silane + adhesive). After surface treatment, a resin cement layer was applied to the surface and all specimens were subjected to biaxial flexural strength (BFS) test with treated surfaces loaded in tension (1 mm/min). The Weibull analyses and complementary analyses were also performed. Statistical analysis was done with 2-way ANOVA and the Tukey test (α = 0.05). RESULTS ANOVA revealed that the factors "etching time" (p = 0.0003) and "bonding agent" (p = 0.007) were statistically significant. In the overall analysis, the HF120S group (272.02 ± 35.30A MPa) presented significantly higher BFS than that of HF120C (218.45 ± 17.15CD MPa) and HF20S (228.40 ± 37.83BCDMPa). On the other hand, the HF20A group (208.92 ± 31.16D MPa) had significantly lower BFS than HF120S (272.02 ± 35.30A), HF120A (254.42 ± 26.87ABC) and HF120SA (259.30 ± 36.55AB) groups (Tukey). The Weibull modulus (m) of all groups was significantly different from each other (p = 0.000). CONCLUSIONS Regardless of etching time, the application of silane alone is sufficient to increase the flexural strength of glass ceramic, eliminating the need for the application of adhesive systems. Moreover, if only silane or adhesive is applied, 120-s HF application should increase the flexural resistance of the lithium disilicate ceramic. CLINICAL SIGNIFICANCE Applications of adhesive systems after silanization can be suppressed from the surface treatment protocol of glass ceramics, since it does not improve their mechanical strength.
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Affiliation(s)
- Sarah Emille Gomes da Silva
- Department of Dentistry, Federal University of Rio Grande Do Norte (UFRN), Av. Salgado FilhoLagoa Nova, Natal, RN, CEP, 178759056-000, Brazil
| | - Gabriela Monteiro de Araújo
- Department of Dentistry, Oral Science, Federal University of Rio Grande Do Norte (UFRN), Av. Salgado FilhoLagoa Nova, Natal, RN. CEP, 178759056-000, Brazil
| | - Karina Barbosa Souza
- Institute of Science and Technology, Univ Estadual Paulista - UNESP, Francisco Jose Longo, Av. Eng, Sao Jose dos Campos, SP, 777, Brazil
| | - Dayanne Monielle Duarte Moura
- Department of Dentistry, State University of Rio Grande Do Norte (UERN), Rua Almino Afonso, 478 - Centro - Mossoró/RN CEP: 59.610-210, Rio, Brazil
| | - Iana Lamadrid Aurélio
- Department of Restorative Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
| | - Liliana Gressler May
- Department of Restorative Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
| | | | - Yu Zhang
- School of Dental Medicine, Department of Preventive and Restorative, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Rodrigo Othávio de Assunção E Souza
- Department of Dentistry, Federal University of Rio Grande Do Norte (UFRN), Av. Salgado FilhoLagoa Nova, Natal, RN, CEP, 178759056-000, Brazil.
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18
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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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19
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Hu B, Hu Y, Li X, Gao J, Sun R, Zhan D, Sano H, Fu J. Shear bond strength of different bonding agents to orthodontic metal bracket and zirconia. Dent Mater J 2022; 41:749-756. [PMID: 36070928 DOI: 10.4012/dmj.2022-028] [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] [Indexed: 11/23/2022]
Abstract
This study aimed to evaluate the shear bond strength (SBS) of four bonding agents used to bond metal brackets to zirconia under different storage conditions. Four bonding agents were used [FLC: (Fuji ORTHO LC), XT: (TransbondTM XT), RUC-SBU: (Rely XTM Ultimate Clicker Adhesive Resin Cement+Single Bond Universal), and RUC-GBU: (Rely XTM Ultimate Clicker Adhesive Resin Cement+Gluma Bond Universal)] to bond two types of metal brackets (PT/3M) to zirconia surfaces, and they were stored in water at 37ºC for 24 h or thermocycling for 3,000 cycles. The SBS data of RUC-SBU and RUC-GBU using PT brackets were significantly higher than those of 3M brackets before and after thermocycling. It could be concluded that RUC-SBU and RUC-GBU could offer sufficient bond strength between metal brackets and zirconia for the short term compared with FLC and XT. The design of brackets can significantly affect the bond strength to zirconia.
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Affiliation(s)
- Bo Hu
- School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Disease
| | - Yichun Hu
- School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Disease
| | - Xiangyi Li
- School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Disease
| | - Jiayang Gao
- School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Disease
| | - Ruitong Sun
- School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Disease
| | - Desong Zhan
- Department of Dental Materials Science, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Disease
| | - Hidehiko Sano
- Department of Restorative Dentistry, Division of Oral Health Science, Faculty of Dental Medicine, Hokkaido University
| | - Jiale Fu
- Department of Dental Materials Science, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Disease
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20
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Rhombohedral Phase Formation in Yttria-Stabilized Zirconia Induced by Dental Technical Tools and Its Impact on Dental Applications. MATERIALS 2022; 15:ma15134471. [PMID: 35806592 PMCID: PMC9267609 DOI: 10.3390/ma15134471] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/16/2022] [Accepted: 06/23/2022] [Indexed: 02/01/2023]
Abstract
In the study the influence of different dental technical tools on the surface temperature and phase composition of fixed dental prostheses (FDPs) made of yttria-partially stabilized zirconia polycrystals (3Y-/4Y-/5Y-PSZ) was investigated. FDPs were fabricated by using computer-aided manufacturing (CAM). The FDPs were treated with a contra-angle handpiece equipped with different burs and polishers. The resulting surface temperatures were measured with a thermographic camera, and the resulting phase transformations were investigated by X-ray diffraction and quantified by Rietveld refinement. Processing with burs resulted in no phase transformation, but a preferred orientation shift. Using coarse polisher induced a phase transformation to the rhombohedral phase, while fine polishers produced no relevant phase transformations and no preferred orientation shift. Compared to the monoclinic phase (ca. 9% theoretical volume increase), which is associated with low-temperature degradation (LTD), the rhombohedral phase is much more voluminous (ca. 15% theoretical volume increase) and distorted and, therefore, has a greater degradation potential.
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Physical Properties and Color Stainability by Coffee and Red Wine of Opaque and High Translucency Zirconia Dental Ceramics after Hydrothermal Degradation. Int J Biomater 2022; 2022:1571729. [PMID: 35637678 PMCID: PMC9148229 DOI: 10.1155/2022/1571729] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/25/2022] [Accepted: 04/28/2022] [Indexed: 11/18/2022] Open
Abstract
The objective was to evaluate the bending strength, phase transformation, roughness, and color stainability by coffee and red wine of opaque and high translucency yttria-stabilized zirconia before and after hydrothermal degradation in saline solution or oral mouthwash. Presintered zirconia blocks with medium opacity (ZrO2-3 mol. % of Y2O3) designed as ZrOp and high translucency zirconia (5.2 mol. % of Y2O3) designed as ZrTrans were used. Specimens (n = 80/group) were cut and sintered at 1500°C for 2 h. The specimens were hydrothermally degraded in an autoclave (134°C–1.8 kg/cm2) for 20 h in saline solution (0.5 g/L) and oral mouthwash solution (0.02% sodium fluoride, without alcohol and with 21.6% alcohol). After hydrothermal degradation, the samples were immersed in containers with coffee or red wine for 14 days to determine their color stainability. The results showed that the ZrOp had a higher bending strength than the ZrTrans before and after hydrothermal aging. In ZrOp and ZrTrans, the roughness increased after hydrothermal degradation. ZrOp samples had a higher Ra roughness than the ZrTrans samples. Roughness did not change after immersion in coffee or red wine. The X-ray diffraction (XRD) results showed that ZrOp samples underwent a tetragonal to monoclinic phase transformation, while ZrTrans samples were unchanged. Both ZrOp and ZrTrans samples changed color after immersion in coffee and red wine.
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Sato TP, Arata A, de Miranda LM, Bottino MA, de Melo RM, Zhang Y, Souza ROA. Effect of Porcelain-to-Zirconia Ratio and Bonding Strategy on the Biaxial Flexural Strength and Weibull Characteristics of a Stress-Free Bilayer CAD/CAM Ceramic System. INT J PROSTHODONT 2022; 35:469-479. [PMID: 36125871 PMCID: PMC9974335 DOI: 10.11607/ijp.7551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
PURPOSE To evaluate the biaxial flexural strength of different porcelain-to-zirconia thickness ratios and bonding strategies of a stress-free bilayer CAD/CAM ceramic system. MATERIALS AND METHODS A total of 60 zirconia discs (diameter: 15 mm; thickness: 0.3 or 0.5 mm; n = 30 for each thickness) were divided into six groups (n = 10 each) according to porcelain-to-zirconia ratio and bonding strategy: VM/Zr (control): zirconia discs veneered with a feldspathic ceramic (VM 9, Vita) in 0.9-mm and 0.7-mm thicknesses using a conventional hand-layering technique; VB/Zr-SBU: zirconia discs airborne particle-abraded with 50-μm Al2O3 particles followed by an MDP primer application (Single Bond Universal, 3M) and bonded to the porcelain with a resin cement (Panavia F 2.0, Kuraray); and VB/Zr-RC: zirconia discs airborne particle-abraded with 30-μm silica-coated Al2O3 particles and silanized and bonded to the porcelain with the same resin cement. Before cementation, the VB (Vitablocs II) discs were etched with 5% hydrofluoric acid (60 seconds), followed by silane application. The bilayers (thickness = 1.2 mm) were loaded with 750 g while light curing the resin cement. Two porcelain-to-zirconia thickness ratios were evaluated: 0.9: 0.3 mm and 0.7: 0.5 mm. All groups were subjected to 106 mechanical cycles, followed by a biaxial flexural test. Data (MPa) were subjected to two-way analysis of variance (ANOVA), Tukey test (5%), and Weibull analyses. RESULTS Two-way ANOVA revealed that the factor porcelain-to-zirconia ratio (P = .0556) was not significant; however, the bonding strategy factor was statistically significant. Among the 0.5-mm zirconia groups, the VB/Zr-SBU group presented higher flexural strength (s) than the VM/Zr or VB/Zr-RC groups. Similar results were also found for the 0.3-mm zirconia groups, in which the VB/Zr-SBU group also presented higher strength than the others, which were similar in comparison (Tukey). The Weibull modulus was similar among the groups; however, the characteristic strength was significantly different (P = .000). CONCLUSION The zirconia bonding strategy with 50-μm Al2O3 airborne-particle abrasion, followed by a primer application, increases the flexural strength of a stress-free bilayer CAD/CAM ceramic system.
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Affiliation(s)
- Tabata Prado Sato
- Institute of Science and Technology, Universidade Estadual Paulista, São José dos Campos, Brazil
| | - Anelyse Arata
- Nanoscience and Advanced Materials Program, Federal University of ABC, Bangú, Brazil
| | - Larissa Mendonça de Miranda
- Federal University of Rio Grande do Norte, Department of Dentistry, Division of Prosthodontics, Natal, Brazil
| | - Marco Antonio Bottino
- Department of Dental Materials Institute of Science and Technology, University Estadual Paulista, São José dos Campos, Brazil
| | - Renata Marques de Melo
- Department of Dental Materials Institute of Science and Technology, University Estadual Paulista, São José dos Campos, Brazil
| | - Yu Zhang
- University of Pennsylvania, School of Dental Medicine, Department of Preventive and Restorative Sciences, Philadelphia, Pennsylvania, USA
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Effect of finishing/polishing techniques and aging on topography, C. albicans adherence, and flexural strength of ultra-translucent zirconia: an in situ study. Clin Oral Investig 2022; 26:889-900. [PMID: 34448074 PMCID: PMC9902030 DOI: 10.1007/s00784-021-04068-3] [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: 05/28/2020] [Accepted: 07/01/2021] [Indexed: 02/08/2023]
Abstract
OBJECTIVE To investigate the influence of different finishing/polishing techniques and in situ aging on the flexural strength (σ), surface roughness, and Candida albicans adherence of 5 mol% yttria-stabilized zirconia (ultratranslucent zirconia). MATERIALS AND METHODS A total of 120 zirconia bars (Prettau Anterior, Zirkonzahn) with dimensions of 8 × 2 × 0.5 mm were divided into 8 groups (n = 15) according to two factors: "in situ aging" (non-aged and aged (A)) and "finishing/polishing" (control (C), diamond rubber polishing (R), coarse grit diamond bur abrasion (B), and coarse grit diamond bur abrasion + diamond rubber polishing (BR)). Half of the samples from each group were subjected to a 60-day in situ aging by fixing the bars into cavities prepared in the posterior region of the base of complete or partial dentures of 15 patients. The samples were then subjected to the mini flexural (σ) test (1 mm/min). A total of 40 zirconia blocks (5 × 5 × 2 mm) were prepared and subjected to roughness (Ra) analyses and fungal adherence and complementary analyses (X-ray diffraction (XRD) and scanning electron microscopy (SEM)). The data of mean σ (MPa) and roughness Ra (μm) were statistically analyzed by two-way and one-way ANOVA, respectively, and Tukey's test. The Weibull analysis was performed for σ data. The fungal adhesion (Log CFU/mL) data were analyzed by Kruskal-Wallis tests. RESULTS For flexural resistance, the "finishing/polishing" factor was statistically significant (P = 0.0001); however, the "in situ aging" factor (P = 0.4458) was not significant. The non-aged (507.3 ± 115.7 MPa) and aged (487.6 ± 118.4 MPa) rubber polishing groups exhibited higher mean σ than the other techniques. The non-aged (260.2 ± 43.3 MPa) and aged (270.1 ± 48.8 MPa) bur abrasion groups presented lower σ. The coarse-grit diamond bur abrasion group (1.82 ± 0.61 µm) presented the highest roughness value (P = 0.001). Cell adhesion was not different among groups (P = 0.053). Group B presented the most irregular surface and the highest roughness Ra of 0.61 m. CONCLUSIONS The finishing of ultratranslucent zirconia might be preferably done with a diamond rubber polisher. Moreover, the protocols used did not interfere with Candida albicans adhesion. CLINICAL RELEVANCE Coarse-grit diamond burs might be avoided for finishing ultratranslucent monolithic zirconia, which might be preferably performed with a diamond rubber polisher.
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24
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Wertz M, Hoelzig H, Kloess G, Hahnel S, Koenig A. Influence of Manufacturing Regimes on the Phase Transformation of Dental Zirconia. MATERIALS 2021; 14:ma14174980. [PMID: 34501071 PMCID: PMC8434073 DOI: 10.3390/ma14174980] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/26/2021] [Accepted: 08/29/2021] [Indexed: 11/23/2022]
Abstract
Background: The influence of typical manufacturing regimes for producing fixed dental prostheses (FDPs) from yttria partly-stabilized zirconia polycrystals (3Y/4Y/5Y-TZP) on the phase composition is quantified. Methods: Fixed dental prostheses (FDPs) were designed using a CAD process and machined from different Y-TZP blanks from two manufacturers differing in yttria contents. Subsequent to sintering, the FDPs were glaze fired and air-blasted using alumina particles. Phase composition was determined with X-ray diffraction and quantified with Rietveld refinement. Results: The blanks from VITA Zahnfabrik (VITA YZ HT, VITA YZ ST, VITA YZ XT) and Dental Direct (DD Bio ZX2, DD cube ONE, DD cube X2) featured a rhombohedral portion with rather small crystallites and a small monoclinic portion for 3Y/4Y-TZPs, which increased after machining and disappeared after sintering. Glaze firing and air-blasting with alumina particles had no significant influence on the phase composition. Conclusion: The phase history of dental zirconia is revealed, which may have implications on further processing and aging of the FDP (e.g. low temperature degradation) in mouth.
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Affiliation(s)
- Markus Wertz
- Department of Prosthodontics and Material Sciences, Leipzig University, 04103 Leipzig, Germany; (M.W.); (S.H.)
| | - Hieronymus Hoelzig
- Institute of Mineralogy, Crystallography and Materials Science, Leipzig University, 04103 Leipzig, Germany; (H.H.); (G.K.)
| | - Gert Kloess
- Institute of Mineralogy, Crystallography and Materials Science, Leipzig University, 04103 Leipzig, Germany; (H.H.); (G.K.)
| | - Sebastian Hahnel
- Department of Prosthodontics and Material Sciences, Leipzig University, 04103 Leipzig, Germany; (M.W.); (S.H.)
| | - Andreas Koenig
- Department of Prosthodontics and Material Sciences, Leipzig University, 04103 Leipzig, Germany; (M.W.); (S.H.)
- Correspondence:
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25
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Shin HS, Lee JS. Comparison of surface topography and roughness in different yttrium oxide compositions of dental zirconia after grinding and polishing. J Adv Prosthodont 2021; 13:258-267. [PMID: 34504677 PMCID: PMC8410306 DOI: 10.4047/jap.2021.13.4.258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/13/2021] [Accepted: 08/20/2021] [Indexed: 11/08/2022] Open
Abstract
PURPOSE The purpose of this study was to compare the surface roughness, phase transformation, and surface topography of dental zirconia with three different yttrium oxide compositions under same grinding and polishing conditions. MATERIALS AND METHODS Three zirconia disks (IPS e.max ZirCAD LT, MT, MT multi, Ivoclar Vivadent AG, Schaan, Liechtenstein) were selected for experimental materials. Sixty-nine bar-shaped specimens were fabricated as 12.0 × 6.0 × 4.0 mm using a milling machine and glazing was conducted on 12.0 × 6.0 mm surface by same operator. With a custom polishing device, 12.0 × 6.0 mm surfaces were polished under same condition. Surface roughness (Ra[µm]) was measured before grinding (C), after grinding (G), and at every 3 steps of polishing (P1, P2, P3). X-ray diffraction and FE-SEM observation was conducted before grinding, after grinding, and after fine polishing (P3). Statistical analysis of surface roughness was performed using Kruskal-Wallis test and Mann-Whitney-U test was used as a post hoc test (α = .05). RESULTS There were no significant differences of surface roughness between LT, MT, and MM groups. In LT, MT, and MM groups, P3 groups showed significantly lower surface roughness than C groups. X-ray diffraction showed grinding and polishing didn't lead to phase transformation on zirconia surface. In FE-SEM images, growths in grain size of zirconia were observed as yttrium oxide composition increases. CONCLUSION Polished zirconia surface showed clinically acceptable surface roughness, but difference in yttrium oxide composition had no significant influence on the surface roughness. Therefore, in clinical situation, zirconia polishing burs could be used regardless of yttrium oxide composition.
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Affiliation(s)
- Hyun-Sub Shin
- Department of Prosthodontics, College of Dentistry, Dankook University, Cheonan, Republic of Korea
| | - Joon-Seok Lee
- Department of Prosthodontics, College of Dentistry, Dankook University, Cheonan, Republic of Korea
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Øilo M, Haugli K, Rønold HJ, Ulsund AH, Ruud A, Kvam K. Pre-cementation procedures' effect on dental zirconias with different yttria content. Dent Mater 2021; 37:1425-1436. [PMID: 34330519 DOI: 10.1016/j.dental.2021.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 04/26/2021] [Accepted: 07/07/2021] [Indexed: 11/30/2022]
Abstract
OBJECTVE Several pre-cementation procedures have been advocated to enhance adhesion between zirconia and resin-based cement. There is, however, limited documentation on how these pre-treatments affect the strength of zirconia crowns as most tests are performed on discs or bars. The aim was to assess the effect of pre-cementation procedures on fracture mode, fracture strength and cement retention on zirconia. METHODS Two dental zirconia materials with different yttria content were assessed (<4 and>5 mol%). Both discs (n = 45) and crown-shaped specimens (n = 30) of the two materials were pretreated with either air-abrasion or hot-etching with KHF2 and compared with untreated controls with regards to surface roughness, crystallography, wettability, cement adhesion and fracture strength. RESULTS AND SIGNIFICANCE Air-abrasion improves adhesion and strength of zirconia with moderate yttria content (<4 mol%). Acid etching with heated KHF2 showed the best effect on strength and cement retention on zirconia with higher yttria content (>5 mol%). Application of KHF2 was, however, complicated on crown-shaped specimens. Pre-treatment and cementation protocols should be optimized for different dental zirconias to improve both strength and retention.
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Affiliation(s)
- Marit Øilo
- NIOM, Nordic Institute of Dental Materials, Oslo, Norway; Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway.
| | - Ketil Haugli
- NIOM, Nordic Institute of Dental Materials, Oslo, Norway; OSLOMET, Oslo Metropolitan University, Oslo, Norway
| | - Hans Jacob Rønold
- NIOM, Nordic Institute of Dental Materials, Oslo, Norway; Department of Clinical Dentistry, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - Amanda H Ulsund
- Department of Clinical Dentistry, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - Amund Ruud
- NIOM, Nordic Institute of Dental Materials, Oslo, Norway
| | - Ketil Kvam
- NIOM, Nordic Institute of Dental Materials, Oslo, Norway
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Kilinc H, Sanal FA. Effect of sintering and aging processes on the mechanical and optical properties of translucent zirconia. J Prosthet Dent 2021; 126:129.e1-129.e7. [PMID: 33965239 DOI: 10.1016/j.prosdent.2021.03.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 03/24/2021] [Accepted: 03/24/2021] [Indexed: 02/04/2023]
Abstract
STATEMENT OF PROBLEM Sintering holding times and aging conditions may affect the optical, mechanical, and structural properties of polychromatic multitranslucent zirconia. However, a consensus on the ideal sintering condition for this material is lacking. PURPOSE The purpose of this in vitro study was to investigate the effect of different sintering holding and autoclave aging times on the flexural strength (FS), grain size, and translucency parameter (TP00) of a translucent zirconia. MATERIAL AND METHODS Sixty bar-shaped and 60 rectangular-shaped specimens were prepared from computer-aided design and computer-aided manufacturing (CAD-CAM) zirconia blocks and split into 2 groups to be sintered at 1550 °C for different holding times (regular: 2 hours, prolonged: 5 hours). The specimens were then divided into 3 subgroups and subjected to aging processes (control, aging for 60 minutes, aging for 120 minutes). FS values were obtained by using a 3-point bend test and Weibull analysis was conducted. Grain size evaluations were performed by using scanning electron microscope (SEM) observations. TP00 was measured with a spectrophotometer. Statistical evaluation included the Kolmogorov-Smirnov, 2-way ANOVA, and Tukey HSD tests (α=.05). RESULTS The sintering procedure, aging, and their interaction significantly influenced the TP00 (P<.05). FS values and grain sizes were affected by aging only (P<.001). Both aging times resulted in reduced FS and increased grain sizes. Prolonged sintering in combination with 120 minutes of aging negatively affect the TP00 scores (P<.05). CONCLUSIONS FS values were similar under regular and prolonged sintering. Prolonged sintering led to a decrease in translucency after 120 minutes of aging. Steam autoclave aging can affect the optical and mechanical properties of translucent zirconia.
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Affiliation(s)
- Hamiyet Kilinc
- Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Bolu Abant Izzet Baysal University, Bolu, Turkey.
| | - Fatma A Sanal
- Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Bolu Abant Izzet Baysal University, Bolu, Turkey
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The Influence of Surface Preparation, Chewing Simulation, and Thermal Cycling on the Phase Composition of Dental Zirconia. MATERIALS 2021; 14:ma14092133. [PMID: 33922280 PMCID: PMC8122781 DOI: 10.3390/ma14092133] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/08/2021] [Accepted: 04/13/2021] [Indexed: 02/04/2023]
Abstract
The effect of dental technical tools on the phase composition and roughness of 3/4/5 yttria-stabilized tetragonal zirconia polycrystalline (3y-/4y-/5y-TZP) for application in prosthetic dentistry was investigated. Additionally, the X-ray diffraction methods of Garvie-Nicholson and Rietveld were compared in a dental restoration context. Seven plates from two manufacturers, each fabricated from commercially available zirconia (3/4/5 mol%) for application as dental restorative material, were stressed by different dental technical tools used for grinding and polishing, as well as by chewing simulation and thermocycling. All specimens were examined via laser microscopy (surface roughness) and X-ray diffraction (DIN EN ISO 13356 and the Rietveld method). As a result, the monoclinic phase fraction was halved by grinding for the 3y-TZP and transformed entirely into one of the tetragonal phases by polishing/chewing for all specimens. The tetragonal phase t is preferred for an yttria content of 3 mol% and phase t″ for 5 mol%. Mechanical stress, such as polishing or grinding, does not trigger low-temperature degradation (LTD), but it fosters a phase transformation from monoclinic to tetragonal under certain conditions. This may increase the translucency and deteriorate the mechanical properties to some extent.
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29
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Silva GC. A straightforward technique to obtain a subgingival nonglazed polished zirconia area in monolithic implant-supported prostheses. J Prosthet Dent 2020; 127:368-370. [PMID: 33248677 DOI: 10.1016/j.prosdent.2020.07.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/22/2020] [Accepted: 07/22/2020] [Indexed: 10/22/2022]
Affiliation(s)
- Guilherme C Silva
- Adjunct Professor, Department of Restorative Dentistry, School of Dentistry, Federal University of Minas Gerais, (UFMG), Belo Horizonte, Brazil.
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30
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Skjold A, Schriwer C, Gjerdet NR, Øilo M. Effect of artificial aging on high translucent dental zirconia: simulation of early failure. Eur J Oral Sci 2020; 128:526-534. [PMID: 33058363 DOI: 10.1111/eos.12739] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/04/2020] [Accepted: 09/10/2020] [Indexed: 01/02/2023]
Abstract
Higher yttria content enhances the translucency and appearance of dental zirconia materials. Alterations in material composition also affect mechanical properties. The aim of this study was to compare the fracture load after artificial short-term aging of monolithic, full-contour zirconia crowns with different amounts of yttria-stabilization. Sixty crowns (thirty super high translucent crowns (5Y-Z) and thirty high translucent crowns (3Y-Z)) were produced to fit a model of a premolar with a shallow chamfer preparation. The crowns were cemented with self-adhesive resin cement on composite abutments. For each zirconia type, three groups of crowns (n = 10) were allocated to: (i) cyclic loading (200 N, 1 Hz, 30,000 cycles), (ii) hydrothermal aging (3 × 20 min, 134°C 3.2 bar), or (iii) no treatment (control). Surviving crowns from the aging process were quasistatically loaded until fracture. The 3Y-Z crowns had statistically significantly higher fracture values (3,449 N) than the 5Y-Z crowns (1,938 N). The aging procedures did not affect load at fracture. Fractographic analysis showed that fractures started either at the crown margin or at the occlusal intaglio area. Higher yttria content leads to a reduction in material strength and damage tolerance, and this should be reflected in recommendations for clinical use.
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Affiliation(s)
- Anneli Skjold
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Christian Schriwer
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Nils R Gjerdet
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Marit Øilo
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway
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31
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Abdalla MM, Ali IA, Khan K, Mattheos N, Murbay S, Matinlinna JP, Neelakantan P. The Influence of Surface Roughening and Polishing on Microbial Biofilm Development on Different Ceramic Materials. J Prosthodont 2020; 30:447-453. [DOI: 10.1111/jopr.13260] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2020] [Indexed: 01/08/2023] Open
Affiliation(s)
- Mohamed Mahmoud Abdalla
- Faculty of Dentistry The University of Hong Kong Hong Kong SAR
- Dental Biomaterials Department, Faculty of Dental Medicine Al‐Azhar University Cairo Egypt
| | - Islam A.A. Ali
- Faculty of Dentistry The University of Hong Kong Hong Kong SAR
| | - Khadija Khan
- Faculty of Dentistry The University of Hong Kong Hong Kong SAR
| | - Nikos Mattheos
- Department of Dental Medicine Karolinska Institutet Stockholm Sweden
- Chulalongkorn University Thailand
| | - Sukhdeep Murbay
- Faculty of Dentistry The University of Hong Kong Hong Kong SAR
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Lobo CMM, Sacorague SCMC, Silva NRD, Costa AKF, Alves LMM, Bottino MA, Özcan M, Souza RODAE, Melo RMD. Effect of glazing application side and mechanical cycling on the biaxial flexural strength and Weibull characteristics of a Y-TZP ceramic. J Appl Oral Sci 2020; 28:e20200438. [PMID: 32997088 PMCID: PMC7521420 DOI: 10.1590/1678-7757-2020-0438] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 07/28/2020] [Indexed: 11/21/2022] Open
Abstract
Glaze application on monolithic zirconia (Y-TZP) can be a practical approach to improve the mechanical properties of this material.
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Affiliation(s)
- Carolina Machado Martinelli Lobo
- Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Instituto de Ciência e Tecnologia, Departamento de Materiais Dentários e Prótese, São José dos Campos, São Paulo, Brasil
| | - Sâmia Carolina Mota Cavalcanti Sacorague
- Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Instituto de Ciência e Tecnologia, Departamento de Materiais Dentários e Prótese, São José dos Campos, São Paulo, Brasil
| | - Nathalia Ramos da Silva
- Universidade Federal do Rio Grande do Norte (UFRN), Departamento de Odontologia, Natal, Rio Grande do Norte, Brasil
| | - Anna Karina Figueiredo Costa
- Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Instituto de Ciência e Tecnologia, Departamento de Materiais Dentários e Prótese, São José dos Campos, São Paulo, Brasil
| | - Larissa Marcia Martins Alves
- Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Instituto de Ciência e Tecnologia, Departamento de Materiais Dentários e Prótese, São José dos Campos, São Paulo, Brasil
| | - Marco Antônio Bottino
- Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Instituto de Ciência e Tecnologia, Departamento de Materiais Dentários e Prótese, São José dos Campos, São Paulo, Brasil
| | - Mutlu Özcan
- University of Zurich, Center for Dental and Oral Medicine, Division of Dental Biomaterials, Clinic for Reconstructive Dentistry, Zurich, Switzerland
| | | | - Renata Marques de Melo
- Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Instituto de Ciência e Tecnologia, Departamento de Materiais Dentários e Prótese, São José dos Campos, São Paulo, Brasil
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