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Flexural Strength Properties of Five Different Monolithic Computer-Aided Design/Computer-Aided Manufacturing Ceramic Materials: An In Vitro Study. Cureus 2023; 15:e36958. [PMID: 37009356 PMCID: PMC10064933 DOI: 10.7759/cureus.36958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2023] [Indexed: 04/03/2023] Open
Abstract
Objective The purpose of this in vitro study is to compare the flexural strength and Weibull modulus of 5 different monolithic computer-aided design/computer-aided manufacturing (CAD/CAM) ceramics. Methods A total of 50 specimens were fabricated, 10 from each of the following materials: lithium disilicate-based ceramic (IPS e.max CAD), zirconia -reinforced lithium-silicate ceramic (Vita Suprinity), leucite-based glass ceramic (IPS Empress CAD), and two zirconia-based ceramics (Zenostar and CopraSmile). The specimens were 4 mm wide, 2 mm thick, and 16 mm long. Flexural strength test was executed using a universal testing machine (Model 5980, Instron Industrial Products, Norwood, MA, USA). The two-parameter Weibull distribution function was used to analyze the variability of flexural strength values. Statistical analysis was performed on SPSS Version 23 (IBM Corp., Armonk, NY, USA) using one-way analysis of variance (ANOVA) and post-hoc Tukey’s test. Results Suprinity had the highest Weibull modulus value, while Empress CAD displayed the lowest value. One-way ANOVA showed significant difference in the flexural strength between the different materials tested (p<0.05). Post-hoc analysis revealed significant differences among all the test groups in terms of flexural strength. Zenostar presented the highest mean flexural strength value (1033.90 MPa), while Empress CAD had the lowest value. Conclusion High-translucency zirconia had superior flexural properties than translucent zirconia, lithium disilicate ceramics, zirconia-reinforced lithium silicate ceramics, and leucite-based glass ceramics.
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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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Koenig V, Bekaert S, Dupont N, Vanheusden A, Le Goff S, Douillard T, Chevalier J, Djaker N, Lamy de la Chapelle M, Amiard F, Dardenne N, Wulfman C, Mainjot A. Intraoral low-temperature degradation of monolithic zirconia dental prostheses: Results of a prospective clinical study with ex vivo monitoring. Dent Mater 2021; 37:1134-1149. [PMID: 33858665 DOI: 10.1016/j.dental.2021.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/25/2021] [Accepted: 03/29/2021] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To investigate the intraoral development and kinetics of low-temperature degradation (LTD) in second-generation 3 mol.% yttria-doped tetragonal zirconia polycrystal (3Y-TZP) monolithic prostheses, as well as the influence of masticatory mechanical stress and glaze layer on it. METHODS A total of 101 posterior tooth elements were included in a prospective clinical study, which included ex vivo LTD monitoring (at baseline, 6 months, 1 year, and 2 years) using Raman spectroscopy (n = 2640 monoclinic phase measurement points per evaluation time) and SEM. Four types of areas (1-2 mm2 surface, 6 on molars, and 4 on premolars) were analyzed on each element surface: occlusal, axial, glazed, or unglazed. Raman depth mapping and high-resolution SEM were performed on the selected samples. RESULTS LTD developed in 3Y-TZP monolithic restorations 6 months after intraoral placement and progressed with time. After two years, the tetragonal-to-monoclinic transformation was non-uniform, with the presence of localized clusters of transformed grains. In axial areas, the grain aspect was typical of the classical nucleation-growth process reported for LTD, which progresses from the surface to a depth of several tens of microns. However, in occlusal areas, tribological stress generated surface crushing and grain pull-out from the clusters, which induced an underestimation of the aging process when the evaluation was limited to monoclinic phase quantification. Glazing cannot be considered a protection against LTD. SIGNIFICANCE If LTD occurs in dental prostheses in the same way as in orthopedic prostheses, its clinical impact is unknown and needs to be further studied.
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Affiliation(s)
- V Koenig
- Dental Biomaterials Research Unit (d-BRU), University of Liège (ULiège), 45 Quai G. Kurth, Liège, 4020, Belgium; Department of Fixed Prosthodontics, Institute of Dentistry, University of Liège Hospital (CHU), 45 Quai G. Kurth, Liège, 4020, Belgium
| | - S Bekaert
- Dental Biomaterials Research Unit (d-BRU), University of Liège (ULiège), 45 Quai G. Kurth, Liège, 4020, Belgium; Department of Fixed Prosthodontics, Institute of Dentistry, University of Liège Hospital (CHU), 45 Quai G. Kurth, Liège, 4020, Belgium
| | - N Dupont
- Dental Biomaterials Research Unit (d-BRU), University of Liège (ULiège), 45 Quai G. Kurth, Liège, 4020, Belgium; Department of Fixed Prosthodontics, Institute of Dentistry, University of Liège Hospital (CHU), 45 Quai G. Kurth, Liège, 4020, Belgium
| | - A Vanheusden
- Dental Biomaterials Research Unit (d-BRU), University of Liège (ULiège), 45 Quai G. Kurth, Liège, 4020, Belgium; Department of Fixed Prosthodontics, Institute of Dentistry, University of Liège Hospital (CHU), 45 Quai G. Kurth, Liège, 4020, Belgium
| | - S Le Goff
- Unité de Recherches en Biomatériaux Innovants et Interfaces (URB2i) - EA4462, Faculté de Chirurgie Dentaire, Université Paris Descartes, Sorbonne Paris-Cité, Montrouge, 92120, France
| | - T Douillard
- Université de Lyon, INSA Lyon, CNRS, MATEIS, UMR 5510, F-69621 Villeurbanne, France
| | - J Chevalier
- Université de Lyon, INSA Lyon, CNRS, MATEIS, UMR 5510, F-69621 Villeurbanne, France
| | - N Djaker
- Université Sorbonne Paris Nord, CNRS, UMR 7244, CSPBAT, Laboratoire de Chimie, Structures et Propriétés de Biomatériaux et d'Agents Thérapeutiques, 93017 Bobigny, France
| | - M Lamy de la Chapelle
- Institut des Molécules et Matériaux du Mans (IMMM - UMR6283), Université du Mans, avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
| | - F Amiard
- Institut des Molécules et Matériaux du Mans (IMMM - UMR6283), Université du Mans, avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
| | - N Dardenne
- Department of Public Health, University of Liège, 4000 Liège, Belgium
| | - C Wulfman
- Dental Biomaterials Research Unit (d-BRU), University of Liège (ULiège), 45 Quai G. Kurth, Liège, 4020, Belgium; Unité de Recherches en Biomatériaux Innovants et Interfaces (URB2i) - EA4462, Faculté de Chirurgie Dentaire, Université Paris Descartes, Sorbonne Paris-Cité, Montrouge, 92120, France
| | - A Mainjot
- Dental Biomaterials Research Unit (d-BRU), University of Liège (ULiège), 45 Quai G. Kurth, Liège, 4020, Belgium; Department of Fixed Prosthodontics, Institute of Dentistry, University of Liège Hospital (CHU), 45 Quai G. Kurth, Liège, 4020, Belgium.
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PEKKAN G, PEKKAN K, BAYINDIR BÇ, ÖZCAN M, KARASU B. Factors affecting the translucency of monolithic zirconia ceramics: A review from materials science perspective. Dent Mater J 2020; 39:1-8. [DOI: 10.4012/dmj.2019-098] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Gürel PEKKAN
- Department of Prosthodontics, Faculty of Dentistry, Tekirdag Namik Kemal University
| | - Keriman PEKKAN
- Department of Ceramics and Glass, Faculty of Fine Arts, Kutahya Dumlupinar University
| | | | - Mutlu ÖZCAN
- Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Center for Dental and Oral Medicine, Dental Materials Unit, University of Zürich
| | - Bekir KARASU
- Department of Metallurgical and Materials Engineering, Faculty of Engineering, Eskisehir Technical University
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Kelesi M, Kontonasaki E, Kantiranis N, Papadopoulou L, Zorba T, Paraskevopoulos KM, Koidis P. The effect of different aging protocols on the flexural strength and phase transformations of two monolithic zirconia ceramics. J Appl Biomater Funct Mater 2020; 18:2280800020982677. [DOI: 10.1177/2280800020982677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Introduction: The aim of the present study was to investigate how different aging protocols can affect the flexural strength and phase transformations of yttrium-stabilized zirconia ceramics (Y-TZP) for monolithic restorations. Materials and methods: Bar-shaped specimens from two zirconia ceramics bars were divided into three groups: a. no treatment (c), b. aging in an autoclave (a), and c. thermal cycling (t). The flexural strength was determined by the 3-point bending test and statistical analysis was performed to determine significant differences ( p< 0.05). Weibull statistics was used to analyze the dispersion of strength values while surface microstructural analysis was performed through X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Results: Aging did not significantly affect the flexural strength but differences were recorded between the two groups, with group A presenting higher strength values and m-phase percentages. Conclusions: The observed differences between the two ceramics could be attributed to variations in composition and processing.
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Affiliation(s)
- Maria Kelesi
- Laboratory of Prosthodontics, Dentistry Department, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Eleana Kontonasaki
- Laboratory of Prosthodontics, Dentistry Department, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Nikolaos Kantiranis
- Geology Department, Faculty of Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Lambrini Papadopoulou
- Geology Department, Faculty of Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Triantafyllia Zorba
- Physics Department, Faculty of Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - K M Paraskevopoulos
- Physics Department, Faculty of Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Petros Koidis
- Laboratory of Prosthodontics, Dentistry Department, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
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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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Alfrisany NM, Shokati B, Tam LE, De Souza GM. Simulated occlusal adjustments and their effects on zirconia and antagonist artificial enamel. J Adv Prosthodont 2019; 11:162-168. [PMID: 31297175 PMCID: PMC6609759 DOI: 10.4047/jap.2019.11.3.162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 03/26/2019] [Accepted: 06/11/2019] [Indexed: 11/29/2022] Open
Abstract
PURPOSE The aim of this study was to evaluate the effect of occlusal adjustments on the surface roughness of yttria-tetragonal zirconia polycrystal (Y-TZP) and wear of opposing artificial enamel. MATERIALS AND METHODS Twenty-five Y-TZP slabs from each brand (Lava, 3M and Bruxzir, Glidewell Laboratories) with different surface conditions (Control polished - CPZ; Polished/ground - GRZ; Polished/ground/repolished - RPZ; Glazed - GZ; Porcelain-veneered - PVZ; n=5) were abraded (500,000 cycles, 80 N) against artificial enamel (6 mm diameter steatite). Y-TZP roughness (in µm) before and after chewing simulation (CS) and antagonist steatite volume loss (in mm3) were evaluated using a contact surface profilometer. Y-TZP roughness was analyzed by three-way analysis of variance (ANOVA) and teatite wear by two-way ANOVA and Tukey Honest Difference (HSD) (P=.05). RESULTS There was no effect of Y-TZP brand on surface roughness (P=.216) and steatite loss (P=.064). A significant interaction effect (P<.001) between surface condition and CS on Y-TZP roughness was observed. GZ specimens showed higher roughness after CS (before CS − 3.7 ± 1.8 µm; after CS − 13.54 ± 3.11 µm), with partial removal of the glaze layer. Indenters abraded against CPZ (0.09 ± 0.03 mm3) were worn more than those abraded against PVZ (0.02 ± 0.01 mm3) and GZ (0.02 ± 0.01 mm3). Higher wear caused by direct abrasion against zirconia was confirmed by SEM. CONCLUSION Polishing with an intraoral polishing system did not reduce the roughness of zirconia. Wear of the opposing artificial enamel was affected by the material on the surface rather than the finishing technique applied, indicating that polished zirconia is more deleterious to artificial enamel than are glazed and porcelain-veneered restorations.
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Affiliation(s)
- Najm Mohsen Alfrisany
- Department of Dental Health, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.,Faculty of Dentistry, University of Toronto, Toronto, Canada
| | - Babak Shokati
- Faculty of Dentistry, University of Toronto, Toronto, Canada
| | - Laura Eva Tam
- Faculty of Dentistry, University of Toronto, Toronto, Canada
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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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Monaco C, Llukacej A, Baldissara P, Arena A, Scotti R. Zirconia-based versus metal-based single crowns veneered with overpressing ceramic for restoration of posterior endodontically treated teeth: 5-year results of a randomized controlled clinical study. J Dent 2017; 65:56-63. [DOI: 10.1016/j.jdent.2017.07.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 06/18/2017] [Accepted: 07/05/2017] [Indexed: 12/23/2022] Open
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Alghazzawi TF. The effect of extended aging on the optical properties of different zirconia materials. J Prosthodont Res 2016; 61:305-314. [PMID: 27964931 DOI: 10.1016/j.jpor.2016.11.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 10/12/2016] [Accepted: 11/06/2016] [Indexed: 10/20/2022]
Abstract
PURPOSE The purpose of this study was to determine if the optical properties of zirconia and glass-ceramic (e.max) were affected by low-temperature degradation (aging). METHODS Experiment samples were fabricated with seven zirconia brands (n=10): Zenostar, Zirlux, Katana, Bruxzir, DD-BioZX2, DD-cubeX2, NexxZr; and e.max were used as a control. This resulted in a total of 80 samples in the experiment. The L*, a* and b* were measured for each sample, and then the optical properties including translucency parameter (TP), contrast ratio (CR), and opalescence parameter (OP) were calculated. The samples were aged (20, 40, 60, 80, 100h), and the optical properties were calculated after each interval. RESULTS Most zirconia brands had lower L*, higher a*, higher b* with increased aging, which visually corresponds to darker, redder, and more yellow. Aging also increased CR, lowered TP, and lowered OP. e.max was also affected by aging but still had the highest TP (23.9±2.8), L* (81.7±3.4), and lowest CR (0.41±0.05) compared to any zirconia. The Zenostar had the closest TP (24.1±0.4), and L* (90.2±0.5) values to e.max before aging. However, after 100h of aging, the DD-cubeX2 was least effected and had the highest TP (22.2±0.6) and lowest CR (0.43±0.01) compared with other zirconia samples and highest OP (11.3±0.2) of all ceramic samples. CONCLUSIONS The optical properties of zirconia and e.max materials were affected by aging with the effects increasing with time. The magnitude of change was affected by seven brands of dental zirconia.
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Affiliation(s)
- Tariq F Alghazzawi
- Department of Prosthetic Dental Sciences, College of Dentistry, Taibah University, Medina, Saudi Arabia; Department of Materials Science and Engineering, School of Engineering, The University of Alabama at Birmingham, United States.
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Alghazzawi TF, Janowski GM. Effect of liner and porcelain application on zirconia surface structure and composition. Int J Oral Sci 2016; 8:164-71. [PMID: 27445089 PMCID: PMC5113090 DOI: 10.1038/ijos.2016.20] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2016] [Indexed: 11/13/2022] Open
Abstract
The purpose of this study was to determine if there is an effect of liner and porcelain application (layering and pressing techniques) on the surface of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP), which were exposed to permutations of liner, layered porcelain, and pressed porcelain. Scanning electron microscope (SEM)/energy dispersive spectroscope (EDS) was used to identify changes in composition and microstructure after removing liner and porcelain with hydrofluoric acid. Simulated aging was also conducted to determine the effect of liner and porcelain on low-temperature degradation. The control group had a typical equiaxed grain structure, referred to as unaffected. When covered with liner or porcelain, some areas changed in structure and composition and were termed affected. The frequency of affected structure decreased when liner was covered with either layered porcelain or pressed porcelain. There were statistical differences (P<0.05) in the composition between affected and unaffected for zirconium (layered porcelain with liner: affected=60% (0.8%) (m/m), unaffected=69% (4%), layered porcelain without liner: affected=59% (3%), unaffected=65% (3%)) and oxygen (layered porcelain with liner: affected=35% (2%), unaffected=26% (4%), layered porcelain without liner: affected=35% (3%), unaffected=30% (2%)). However, there were statistical differences (P<0.05) in the composition for zirconium and oxygen of the aged layered porcelain without liner only. The liner should not be used before porcelain application, especially when using the layering technique for zirconia restorations. Furthermore, pressing should be considered the technique of choice over layering.
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Affiliation(s)
- Tariq F Alghazzawi
- Department of Prosthetic Dental Sciences, College of Dentistry, Taibah University, Madina, Kingdom of Saudi Arabia.,Department of Materials Science and Engineering, School of Engineering, The University of Alabama at Birmingham, Birmingham, USA
| | - Gregg M Janowski
- Department of Materials Science and Engineering, School of Engineering, The University of Alabama at Birmingham, Birmingham, USA
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