51
|
Bittar BF, Miranda JS, Simões AC, de Carvalho Ramos N, Machado JPB, Zhang Y, Souza ROA, Leite FPP. Effect of extrinsic pigmentation and surface treatments on biaxial flexure strength after cyclic loading of a translucent ZrO 2 ceramic. Dent Mater 2019; 35:1644-1653. [PMID: 31575489 PMCID: PMC6858620 DOI: 10.1016/j.dental.2019.08.117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 08/12/2019] [Accepted: 08/31/2019] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the influence of extrinsic pigmentation on the biaxial flexural strength and surface topographic of translucent Y-TZP (InCoris TZI - Sirona - USA) subjected to several surface treatments. METHODS Sintered zirconia discs-shaped specimens (n=120) (ø:12mm; thickness:1.2mm; ISO 6872) were prepared and divided (n=15) according to various factors: "extrinsic pigmentation" (n: without; p: with) and "surface treatments" (C: control - as sintered; A: abraded with silica-coated alumina particles (30μm); G: glazed with a thin film of low-fusing porcelain glaze; GH: glazed and etched with 10% hydrofluoridric acid for 60s. Mechanical cycling (1.2×106 cycles, 200N, 3.8Hz) and flexural strength test (1mm/min - 1000kg cell) were performed. Two-way ANOVA and Tukey's were used for statistical test (α=0.05). Weibull analysis was used to evaluate the strength reliability. Samples were analyzed via (1) an optical profilometer to determine the surface roughness (Ra); (2) an X-ray diffraction (XRD) to evaluate phase transformations; and (3) a SEM equipped with an energy dispersive X-ray spectroscopy (EDX) to elucidate morphological properties and chemical compositions. RESULTS Regardless of the surface treatment (p=0.5459) (Cn: 560.16MPa; Gn: 573.36MPa; An: 643.51MPa; GHn: 542.94MPa; Cp: 628.04MPa; Gp: 641.90MPa; Ap: 554.47MPa; GHp :602.84MPa) and extrinsic pigmentation (p=0.1280) there was no difference in the flexural strength among the experimental groups. According to the XRD analysis, phase transformations occurred in the An group (t→m) and in Ap group (t→c). Surface roughness was affected by surface treatments (An - p=0.001) and extrinsic pigmentation (Gp - p=0.001). SIGNIFICANCE The biaxial flexural strength of the tested samples was not affected neither by surface treatments nor by pigmentation, although it can cause phase transformation and promote surface roughness.
Collapse
Affiliation(s)
- Breno Fortes Bittar
- Department of Restorative Dentistry, Federal University of Juiz de Fora (UFJF), Juiz de Fora/MG, Brazil
| | - Jean Soares Miranda
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University - UNESP, São José dos Campos, São Paulo, Brazil
| | - Arthur Chaves Simões
- Department of Restorative Dentistry, Federal University of Juiz de Fora (UFJF), Juiz de Fora/MG, Brazil
| | - Nathália de Carvalho Ramos
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University - UNESP, São José dos Campos, São Paulo, Brazil
| | - João P B Machado
- Federal University of Rio Grande do Norte/UFRN, Health Science Center, Department of Dentistry, Natal-RN/Brazil
| | - Yu Zhang
- New York University College of Dentistry, Department of Biomaterials and Biomimetics, 433 First Avenue, Room 810, New York, NY 10010, USA
| | | | | |
Collapse
|
52
|
Blatz M, Chiche G, Bahat O, Roblee R, Coachman C, Heymann H. Evolution of Aesthetic Dentistry. J Dent Res 2019; 98:1294-1304. [DOI: 10.1177/0022034519875450] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
One of the main goals of dental treatment is to mimic teeth and design smiles in a most natural and aesthetic manner, based on the individual and specific needs of the patient. Possibilities to reach that goal have significantly improved over the last decade through new and specific treatment modalities, steadily enhanced and more aesthetic dental materials, and novel techniques and technologies. This article gives an overview of the evolution of aesthetic dentistry over the past 100 y from a historical point of view and highlights advances in the development of dental research and clinical interventions that have contributed the science and art of aesthetic dentistry. Among the most noteworthy advancements over the past decade are the establishment of universal aesthetic rules and guidelines based on the assessment of natural aesthetic parameters, anatomy, and physiognomy; the development of tooth whitening and advanced restorative as well as prosthetic materials and techniques, supported by the pioneering discovery of dental adhesion; the significant progress in orthodontics and periodontal as well as oral and maxillofacial surgery; and, most recently, the implementation of digital technologies in the 3-dimensional planning and realization of truly natural, individual, and aesthetic smiles. In the future, artificial intelligence and machine learning will likely lead to automation of aesthetic evaluation, smile design, and treatment-planning processes.
Collapse
Affiliation(s)
- M.B. Blatz
- Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - G. Chiche
- Department of Restorative Sciences, Dental College of Georgia, Augusta University, Augusta, GA, USA
| | - O. Bahat
- Private Practice, Beverly Hills, CA, USA
| | - R. Roblee
- Private Practice Limited to Orthodontics, Fayetteville, AR, USA
| | - C. Coachman
- Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Private Practice, Sao Paulo, Brazil
| | - H.O. Heymann
- Division of Operative Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, NC, USA
| |
Collapse
|
53
|
Øilo M, Schriwer C, Flinn B, Gjerdet NR. Monolithic zirconia crowns – wall thickness, surface treatment and load at fracture. Biomater Investig Dent 2019. [DOI: 10.1080/26415275.2019.1642112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Affiliation(s)
- Marit Øilo
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - Christian Schriwer
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Brian Flinn
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - Nils Roar Gjerdet
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway
| |
Collapse
|
54
|
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.
Collapse
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
| | | |
Collapse
|
55
|
Güngör MB, Nemli SK, Bal BT, Tamam E, Yılmaz H, Aydın C. Fracture resistance of monolithic and veneered all-ceramic four-unit posterior fixed dental prostheses after artificial aging. J Oral Sci 2019; 61:246-254. [PMID: 31006735 DOI: 10.2334/josnusd.18-0060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
This study compared the fracture resistance of monolithic and veneered all-ceramic four-unit posterior fixed dental prostheses (FDPs) generated by computer-aided design/computer-aided manufacturing (CAD/CAM) after aging in a mastication simulator. Four-unit FDPs were designed from six different all-ceramic systems: 1) monolithic lithium disilicate (M-E), 2) monolithic zirconia (M-TZI), 3) veneered zirconia by conventional layering (V-L), 4) veneered zirconia by lithium disilicate pressing (V-P), 5) veneered zirconia by lithium disilicate fusing (CAD-F-E), and 6) veneered zirconia by feldspathic ceramic cementing (CAD-C-CB). The specimens were divided into control and aging groups (n = 10 per group). The aging process included both thermocycling and mechanical loading and was followed by fracture resistance testing. All specimens in the M-E, M-TZI, and V-L groups survived; however, all specimens in the V-P group were fractured during artificial aging. The highest fracture resistance values were observed in the M-TZI group. According to the fracture resistance test, connector fractures were the most frequent type of failure. M-TZI and M-E FDPs revealed no failures during aging and showed higher fracture resistance than the veneered groups. Among the veneered zirconia framework groups, V-L FDPs showed the highest success rate during aging, while the fracture resistance was similar among all the veneered zirconia groups.
Collapse
Affiliation(s)
- Merve B Güngör
- Department of Prosthodontics, Faculty of Dentistry, Gazi University
| | - Seçil K Nemli
- Department of Prosthodontics, Faculty of Dentistry, Gazi University
| | - Bilge T Bal
- Department of Prosthodontics, Faculty of Dentistry, Gazi University
| | - Evşen Tamam
- Department of Prosthodontics, Faculty of Dentistry, Gazi University
| | - Handan Yılmaz
- Department of Prosthodontics, Faculty of Dentistry, Gazi University
| | - Cemal Aydın
- Department of Prosthodontics, Faculty of Dentistry, Gazi University
| |
Collapse
|
56
|
LE M, Larsson C, Papia E. Bond strength between MDP-based cement and translucent zirconia. Dent Mater J 2019; 38:480-489. [PMID: 31105161 DOI: 10.4012/dmj.2018-194] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The purpose was to evaluate the bond strength between adhesive cement and translucent zirconia in comparison to conventional zirconia. Four brands of translucent zirconia (BruxZir® HT, Lava™ Plus, Prettau® Anterior, and Prettau® Zirconia) and one conventional zirconia (Kavo Everest® ZS) were evaluated. Specimens were divided into groups depending on the pretreatment of the cementation surface of the zirconia: as-produced, hydrofluoric acid treatment, or sandblasted. The groups underwent three different procedures of artificial aging: water storage (24 h), 5,000 thermocycles, or long-term aging, (water storage 150 days including 37,500 thermocycles) before shear bond strength testing. Sandblasting treatment increased the bond strength significantly for all the brands of zirconia, irrespective of artificial aging procedures, in comparison to the control group. Bond strength between adhesive cement to translucent zirconia is equivalent to conventional zirconia. Sandblasting creates a cementation surface that is more durable than as-produced or hydrofluoric-acid-treated, irrespective of type of zirconia.
Collapse
Affiliation(s)
- Minh LE
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University
| | - Christel Larsson
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University
| | - Evaggelia Papia
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University
| |
Collapse
|
57
|
Lifetime prediction of veneered versus monolithic lithium disilicate crowns loaded on marginal ridges. Dent Mater 2019; 35:511-522. [DOI: 10.1016/j.dental.2019.01.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 12/02/2018] [Accepted: 01/11/2019] [Indexed: 11/19/2022]
|
58
|
Lümkemann N, Eichberger M, Stawarczyk B. Different surface modifications combined with universal adhesives: the impact on the bonding properties of zirconia to composite resin cement. Clin Oral Investig 2019; 23:3941-3950. [PMID: 30756181 DOI: 10.1007/s00784-019-02825-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 01/17/2019] [Indexed: 01/07/2023]
Abstract
OBJECTIVE The purpose of this study was to analyze the impact of plasma treatment and (universal adhesives) UAs on the bonding properties of zirconia. MATERIAL AND METHODS Zirconia specimens (N = 744; n = 186/pretreatment) were prepared, highly polished, and pretreated: (i) plasma (oxygen plasma, 10s, 5 mm), (ii) airborne-particle abrasion (alumina, 50 μm, 0.05 MPa, 5 s, 10 mm), (iii) airborne-particle abrasion + plasma, and (iv) without pretreatment (highly polished surface). Surface roughness (Ra) and surface free energy (SFE) were measured (n = 6/pretreatment). Tensile bond strength (TBS) specimens (n = 180/pretreatment) were further divided (n = 18/conditioning): Clearfil Ceramic Primer (PCG), All-Bond Universal (ABU), Adhese Universal (AU), Clearfil Universal Bond (CUB), G-Premio Bond (GPB), Futurabond U (FBU), iBond Universal (IBU), One Coat 7 Universal (OCU), Scotchbond Universal (SBU), and no conditioning. PCG was luted with Panavia F2.0 and the remaining groups with DuoCem. After storage in distilled water (24 h; 37 °C) and thermocycling (5000×; 5 °C/55 °C), TBS was measured and fracture types (FTs) were determined. Data were analyzed using univariate ANOVA with a partial eta square (ƞP2), the Kruskal-Wallis H, the Mann-Whitney U, and the Chi2 test (P < .05). RESULTS Plasma treatment resulted in an increase of SFE but had no impact on Ra. Airborne-particle abrasion resulted in the highest Ra and a higher TBS when compared with plasma and non-treatment. SBU and AU obtained a higher TBS when compared with PCG. OCU, FBU, ABU, IBU, and GPB indicated comparable TBS to PCG. CUB revealed the lowest TBS. CONCLUSIONS Plasma treatment cannot substitute airborne-particle abrasion when bonding zirconia but MDP-containing adhesives are essential for successful clinical outcomes. CLINICAL RELEVANCE Airborne-particle abrasion with a low pressure (0.05 MPa) in combination with UAs promotes the clinical success of adhesively bonded zirconia restorations.
Collapse
Affiliation(s)
- Nina Lümkemann
- Research Associate of Dental Material Unit, Department of Prosthetic Dentistry, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Marlis Eichberger
- Dental Technician of Dental Material Unit, Department of Prosthetic Dentistry, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Bogna Stawarczyk
- Scientific Head of Dental Material Unit, Department of Prosthetic Dentistry, University Hospital, Ludwig-Maximilians-University, Munich, Germany. .,Department of Prosthetic Dentistry, University Hospital, Ludwig-Maximilians-University Munich, Goethestrasse 70, 80336, Munich, Germany.
| |
Collapse
|
59
|
Optical properties of translucent zirconia: A review of the literature. EUROBIOTECH JOURNAL 2019. [DOI: 10.2478/ebtj-2019-0005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Abstract
Translucent monolithic zirconia is the newest option of zirconia-based ceramics, which aimed to substitute the opaque classic yttria-stabilized tetragonal zirconia polycrystal (Y-TZPs) in more demanding esthetic cases.
The aim of this review was to assess the available literature regarding the optical, chemical and mechanical properties of translucent zirconia ceramics.
This systematic review was developed according to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-analysis) guidelines. An electronic literature search was undertaken through Medline (National Library of Medicine) via PubMed to identify relevant articles, published in the interval 2010-2018. The search was limited to the English language publications, in vitro studies of color and microstructure of translucent zirconia material.
Yttria-stabilized tetragonal zirconia polycrystals (Y-TZPs) has excellent mechanical properties, but its intense white color and high opacity represent an esthetic limit. Cubic zirconia represents a new generation of dental ceramics with molecular structure and physical properties different from the conventional zirconia. Dental manufacturers created new formulations of this restorative material, introducing new cubic varieties of zirconia with improved optical properties. Translucent monolithic zirconia provides a new restorative option that combines strength with improved esthetics, due to its increased translucency. Translucent zirconia is indicated for anterior and posterior restorations but should be used carefully for discolored teeth, because the background color can affect the final esthetic appearance of the restoration.
Collapse
|
60
|
WERNER HKB, AZEVEDO GSF, LIMA LCDS, MARTINEZ CHM, SERAIDARIAN PI. Avaliação da resistência de união de uma cerâmica de óxido de zircônia submetida a tratamentos de superfície por abrasão. REVISTA DE ODONTOLOGIA DA UNESP 2019. [DOI: 10.1590/1807-2577.01019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Resumo Introdução A cimentação adesiva, com cerâmicas puras, é um passo relevante no estabelecimento da longevidade de trabalhos protéticos, sendo estes os melhores materiais utilizados para a reposição de dentes perdidos, de forma a reabilitar o sorriso. O sistema cerâmico de zircônia não se beneficia do tratamento com ácidos e necessita de diferentes métodos para tratar sua superfície, visando à efetividade na união adesiva. Objetivo Avaliar os resultados de diferentes técnicas de jateamento e aplicação de agente de união desenvolvidas para metais e cerâmica de zircônia (Ceramill ZI®), por meio de ensaio de tração, em dois diferentes tratamentos de superfície. Material e método Foram preparadas 20 amostras de Ceramill Zi® (n = 20), em forma de cilindro, e unidas entre si por meio do cimento resinoso (Multilink®), formando 10 espécimes (n = 10). Formaram-se sete grupos experimentais com os mesmos 10 espécimes e estes receberam dois tratamentos de superfície diferentes: abrasão e aplicação de agentes silânicos de união. Resultado A análise estatística mostrou diferenças significativas na resistência à fratura dos espécimes silicatizados com Rocatec®. Os valores de resistência de união à tração, mensurados em MPa, dos grupos 1 a 7, foram, respectivamente: 2,27; 4,48; 8,06; 8,32; 9,15; 10,56 e 10,70. As médias entre os grupos se apresentam estatisticamente significantes, exceto entre os grupos 3 e 4 e entre 6 e 7. Conclusão Os resultados mostraram que o tratamento da superfície cerâmica baseado no método de silicatização promoveu melhor união nos ensaios com Ceramill ZI® e cimentados com Multilink®.
Collapse
|
61
|
Bakitian F, Seweryniak P, Papia E, Larsson C, Vult von Steyern P. Load-Bearing Capacity of Monolithic Zirconia Fixed Dental Prostheses Fabricated with Different Connector Designs and Embrasure Shaping Methods. J Prosthodont 2018; 28:64-70. [DOI: 10.1111/jopr.13002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2018] [Indexed: 11/30/2022] Open
Affiliation(s)
- Fahad Bakitian
- Department of Materials Science and Technology; Faculty of Odontology; Malmö University; Malmö Sweden
- Department of Restorative Dentistry; Faculty of Dentistry; Umm Al-Qura University; Makkah Saudi Arabia
| | | | - Evaggelia Papia
- Department of Materials Science and Technology; Faculty of Odontology; Malmö University; Malmö Sweden
| | - Christel Larsson
- Department of Materials Science and Technology; Faculty of Odontology; Malmö University; Malmö Sweden
| | - Per Vult von Steyern
- Department of Materials Science and Technology; Faculty of Odontology; Malmö University; Malmö Sweden
| |
Collapse
|
62
|
Konstantinidis I, Trikka D, Gasparatos S, Mitsias ME. Clinical Outcomes of Monolithic Zirconia Crowns with CAD/CAM Technology. A 1-Year Follow-Up Prospective Clinical Study of 65 Patients. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15112523. [PMID: 30424474 PMCID: PMC6266146 DOI: 10.3390/ijerph15112523] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 10/29/2018] [Accepted: 11/07/2018] [Indexed: 11/29/2022]
Abstract
Aim/Purpose: The primary aim of this study was to examine the clinical performance of posterior monolithic single crowns in terms of failure or complications and the secondary aim was to assess the quality of these restorations according to the United States Public Health Service (USPHS) criteria. Methods: Ιn a private dental clinic, 65 patients with need of posterior crowns were restored with monolithic zirconia crowns. All the restorations were evaluated 6 and 12 months after their cementation. The modified United States Public Health Service (USPHS) criteria and periodontal parameters were applied for the clinical evaluation of the crowns. Restorations with Alpha or Bravo rating were considered a success. Results: Descriptive statistics and nonparametric tests were used for statistical analysis. Sixty-five patients (mean age: 49.52) were restored with 65 monolithic zirconia crowns. No fracture of the restorations was recorded. The overall success rate was 98.5%. The clinical quality of all crowns was acceptable except for the marginal discoloration of one crown at the 6- and 12-month follow-up examination. Conclusions: In this study, no fracture of single-tooth monolithic crowns occurred and the success rate was high. Monolithic zirconia restorations fabricated is a viable option for the restoration of single posterior teeth.
Collapse
Affiliation(s)
| | - Dimitra Trikka
- Dental Center, 29 Marasli Street, Kolonaki, GR10676 Athens, Greece.
| | | | - Miltiadis E Mitsias
- Dental Center, 29 Marasli Street, Kolonaki, GR10676 Athens, Greece.
- Department of Periodontology & Implant Dentistry, New University College of Dentistry, New York, NY 10010, USA.
| |
Collapse
|
63
|
Vahey BR, Sordi MB, Stanley K, Magini RS, Novaes de Oliveira AP, Fredel MC, Henriques B, Souza JC. Mechanical integrity of cement- and screw-retained zirconium-lithium silicate glass-ceramic crowns to Morse taper implants. J Prosthet Dent 2018; 120:721-731. [DOI: 10.1016/j.prosdent.2018.01.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 01/31/2018] [Accepted: 01/31/2018] [Indexed: 11/26/2022]
|
64
|
Elshiyab SH, Nawafleh N, Walsh L, George R. Fracture resistance and survival of implant-supported, zirconia-based hybrid-abutment crowns: Influence of aging and crown structure. ACTA ACUST UNITED AC 2018; 9:e12355. [PMID: 30105895 DOI: 10.1111/jicd.12355] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 05/18/2018] [Indexed: 11/29/2022]
Abstract
AIM The aim of the present study was to investigate fracture resistance of implant-supported zirconia-based crowns (monolayer vs bilayer) cemented to hybrid abutments. METHODS Monolayer and bilayer zirconia crowns were constructed and cemented to zirconia hybrid abutments. Crowns were divided into two subgroups: (a) untreated control group; and (b) experimental group, which underwent thermal-cycling mechanical loading in a chewing simulator. Up to 1.2 million stress cycles with simultaneous thermocycling (5 and 55°C) were applied. Samples were finally subjected to static load to fracture. Data were analyzed using one-way analysis of variance and t test. Fractured surfaces were observed using scanning electron microscopy. RESULTS Monolayer zirconia crowns had a 100% survival rate upon completion of the thermal mechanical loading, whereas bilayer zirconia crowns had a 50% survival rate. The fracture load of monolayer zirconia crowns was significantly higher than that of bilayer crowns. Moreover, the fracture load was significantly reduced in monolayer zirconia crowns after aging. Monolayer zirconia crowns showed bulk fracture within the monolayer, while bilayer crowns exhibited cohesive fracture within the veneering porcelain only. CONCLUSIONS Monolayer implant-supported hybrid-abutment crowns exhibit significantly higher fracture resistance compared to bilayer crowns, making them better suited to handle higher masticatory loads encountered in the posterior region of the mouth.
Collapse
Affiliation(s)
- Shareen H Elshiyab
- School of Dentistry and Oral Health, Griffith University, Gold Coast, Australia.,Department of Applied Dental Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, Jordan
| | - Noor Nawafleh
- Department of Applied Dental Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, Jordan
| | - Laurence Walsh
- School of Dentistry, University of Queensland, Brisbane, Australia
| | - Roy George
- School of Dentistry and Oral Health, Griffith University, Gold Coast, Australia
| |
Collapse
|
65
|
Nakamura K, Ankyu S, Nilsson F, Kanno T, Niwano Y, Vult von Steyern P, Örtengren U. Critical considerations on load-to-failure test for monolithic zirconia molar crowns. J Mech Behav Biomed Mater 2018; 87:180-189. [PMID: 30077077 DOI: 10.1016/j.jmbbm.2018.07.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 07/19/2018] [Accepted: 07/24/2018] [Indexed: 11/30/2022]
Abstract
Application of monolithic zirconia crowns (MZCs) with reduced thickness to the molar region has been proposed, but potential complications have yet to be fully evaluated in laboratory tests. The present study aimed to develop a clinically relevant load-to-failure test in combination with fatigue treatments involving thermal and mechanical cycling (TC and MC) to evaluate the fracture resistance of molar MZCs. MZCs with a minimal thickness of 0.5 mm were bonded to dies made of resin-based composite (RBC), epoxy resin (EP), or polyoxymethylene-copolymer (POM-C). The samples were either untreated (UT) or subjected to TC (5-55 °C for 1 × 105 cycles) and MC (300 N for 2.4 × 106 cycles). The stress generated by TC and MC was simulated by finite element modeling. The load-to-failure test was performed using an inverse V-shaped two-plane indenter and was followed by fractographic analysis. The median values of fracture load for MZC/RBC and MZC/EP in the TC group were significantly lower than those in the UT group. MC also decreased the median value of fracture load for MZC/RBC significantly, but not that for MZC/EP and MZC/POM-C. Fractography revealed that the fracture started in the cervical area in all groups, which is similar to clinically failed crowns. The simulation confirmed stress concentration at the cervical area in both TC and MC groups. The present study suggests that the load-to-failure test using a two-plane indenter could induce clinically relevant fracture of MZCs, the vulnerability of the MZCs depends largely on the die material employed, and MZCs are more likely to be damaged by thermal fatigue than mechanical fatigue.
Collapse
Affiliation(s)
- Keisuke Nakamura
- Department of Advanced Free Radical Science, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai 980 8575, Japan.
| | - Shuhei Ankyu
- Sweden Dental Sendai (private practice), 1-6-2 Tsutsujigaoka, Miyagino-ku, Sendai 983 0852, Japan
| | - Fritjof Nilsson
- Division of Polymeric Materials, Department of Fibre and Polymer Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - Taro Kanno
- Department of Advanced Free Radical Science, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai 980 8575, Japan
| | - Yoshimi Niwano
- Faculty of Nursing, Shumei University, 1-1 Daigaku-cho, Yachiyo, Chiba 276-0003, Japan
| | - Per Vult von Steyern
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University, SE-205 06 Malmö, Sweden
| | - Ulf Örtengren
- Department of Cariology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, SE-405 30 Gothenburg, Sweden; Department of Clinical Dentistry/Faculty of Health Sciences, The Arctic University of Norway, Tromsø 9037, Norway
| |
Collapse
|
66
|
NISHIOKA G, PROCHNOW C, FIRMINO A, AMARAL M, BOTTINO MA, VALANDRO LF, Renata Marques de MELO. Fatigue strength of several dental ceramics indicated for CAD-CAM monolithic restorations. Braz Oral Res 2018; 32:e53. [DOI: 10.1590/1807-3107bor-2018.vol32.0053] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 05/04/2018] [Indexed: 11/21/2022] Open
|
67
|
Bakitian F, Seweryniak P, Papia E, Larsson C, Vult von Steyern P. Effect of different semimonolithic designs on fracture resistance and fracture mode of translucent and high-translucent zirconia crowns. Clin Cosmet Investig Dent 2018; 10:51-60. [PMID: 29628778 PMCID: PMC5878660 DOI: 10.2147/ccide.s157118] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose The aim of this study was to describe different designs of semimonolithic crowns made of translucent and high-translucent zirconia materials and to evaluate the effect on fracture resistance and fracture mode. Methods One hundred crowns with different designs were produced and divided into five groups (n=20): monolithic (M), partially veneered monolithic (semimonolithic) with 0.3 mm buccal veneer (SM0.3), semimonolithic with 0.5 mm buccal veneer (SM0.5), semimonolithic with 0.5 mm buccal veneer supported by wave design (SMW), and semimonolithic with 0.5 mm buccal veneer supported by occlusal cap design (SMC). Each group was divided into two subgroups (n=10) according to the materials used, translucent and high-translucent zirconia. All crowns underwent artificial aging before loading until fracture. Fracture mode analysis was performed. Fracture loads and fracture modes were analyzed using two-way ANOVA and Fisher's exact probability tests (P≤0.05). Results SM0.3 design showed highest fracture loads with no significant difference compared to M and SMW designs (P>0.05). SM0.5 design showed lower fracture loads compared to SMW and SWC designs. Crowns made of translucent zirconia showed higher fracture loads compared to those made of high-translucent zirconia. M, SM0.3, and all but one of the SMC crowns showed complete fractures with significant differences in fracture mode compared to SMW and SM0.5 crowns with cohesive veneer fractures (P≤0.05). Conclusion Translucent and high-translucent zirconia crowns might be used in combination with 0.3 mm microcoating porcelain layer with semimonolithic design to enhance the esthetic properties of restorations without significantly decreasing fracture resistance of the crowns. If 0.5 mm porcelain layer is needed for a semimonolithic crown, wave design or cap design might be used to increase fracture resistance. In both cases, fracture resistance gained is likely to be clinically sufficient as the registered fracture loads were high in relation to expected loads under clinical use.
Collapse
Affiliation(s)
- Fahad Bakitian
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University, Malmö, Sweden.,Department of Restorative Dentistry, Faculty of Dentistry, Umm Al-Qura University, Makkah, Saudi Arabia
| | | | - Evaggelia Papia
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - Christel Larsson
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - Per Vult von Steyern
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University, Malmö, Sweden
| |
Collapse
|
68
|
Effect of thickness on optical properties of monolithic CAD-CAM ceramics. J Dent 2018; 71:38-42. [DOI: 10.1016/j.jdent.2018.01.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 01/22/2018] [Accepted: 01/25/2018] [Indexed: 11/19/2022] Open
|
69
|
Alp G, Subaşı MG, Seghi RR, Johnston WM, Yilmaz B. Effect of shading technique and thickness on color stability and translucency of new generation translucent zirconia. J Dent 2018; 73:19-23. [PMID: 29597040 DOI: 10.1016/j.jdent.2018.03.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 03/21/2018] [Accepted: 03/24/2018] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE To evaluate the effect of shading technique and thickness on the color stability and translucency of translucent zirconia after coffee thermocycling. METHODS Specimens in different thicknesses (1; 1.5; 2 mm) (n = 4 for each thickness) were sectioned from translucent preshaded zirconia (Pre) and externally shaded zirconia (Ext). After sintering, specimens were glazed and subjected to 10,000 thermocycling in coffee solution. The color coordinates of specimens were measured with a spectroradiometer before and after coffee thermocyling. Color differences and relative translucency parameter (RTP) values were calculated with CIEDE2000 color difference and TPCIEDE2000 formulas. ANOVA was used to analyze the CIEDE2000 color difference and RTP values (α = 0.05). RESULTS According to 2-way ANOVA, no significant effect of shading technique and thickness on the color difference values was found (P > .05). According to 3-way ANOVA, a significant interaction between the shading technique and thickness (P < .0001) was found for RTP. The RTP parameter decreased with the increase in the thickness. Ext specimens presented significantly higher RTP than Pre specimens (P < .0001), except for between Ext 1 mm and Pre 1 mm (P = .179). CONCLUSIONS Neither shading technique nor tested thicknesses affected the color of translucent zirconia. Shading technique and thickness affected the RTP of translucent zirconia. The RTP was inversely affected with the thickness of the material. Externally shaded zirconia presented higher RTP than preshaded zirconia for specimens thicker than 1 mm. CLINICAL SIGNIFICANCE Discoloration with coffee was insignificant for the tested translucent zirconia in tested thicknesses (1, 1.5, 2 mm). When a translucent restoration is intended, thinner externally shaded translucent zirconia restorations should be preferred instead of preshaded translucent zirconia.
Collapse
Affiliation(s)
- Gülce Alp
- Faculty of Dentistry, Department of Prosthodontics, Okan University, Akfirat, Tuzla, 34959, Istanbul, Turkey
| | - Meryem Gülce Subaşı
- Faculty of Dentistry, Department of Prosthodontics, Istanbul Aydin University, Besyol Mah. Akasya Sok., 34295, Istanbul, Turkey
| | - Robert R Seghi
- Division of General Practice and Materials Science, The Ohio State University College of Dentistry, 305 W12th Ave., Columbus, OH 43210, United States
| | - William M Johnston
- Division of General Practice and Materials Science, The Ohio State University College of Dentistry, 305 W12th Ave., Columbus, OH 43210, United States
| | - Burak Yilmaz
- Division of Restorative Science and Prosthodontics, The Ohio State University College of Dentistry, 305 W12th Ave., Columbus, OH 43210, United States.
| |
Collapse
|
70
|
Bankoğlu Güngör M, Karakoca Nemli S. Fracture resistance of CAD-CAM monolithic ceramic and veneered zirconia molar crowns after aging in a mastication simulator. J Prosthet Dent 2018. [DOI: 10.1016/j.prosdent.2017.05.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
71
|
Wille S, Zumstrull P, Kaidas V, Jessen LK, Kern M. Low temperature degradation of single layers of multilayered zirconia in comparison to conventional unshaded zirconia: Phase transformation and flexural strength. J Mech Behav Biomed Mater 2018; 77:171-175. [DOI: 10.1016/j.jmbbm.2017.09.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 09/06/2017] [Indexed: 12/22/2022]
|
72
|
Bakitian F, Seweryniak P, Papia E, Larsson C, Vult von Steyern P. Fracture strength of veneered translucent zirconium dioxide crowns with different porcelain thicknesses. ACTA BIOMATERIALIA ODONTOLOGICA SCANDINAVICA 2017; 3:74-83. [PMID: 29242815 PMCID: PMC5724800 DOI: 10.1080/23337931.2017.1403288] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 10/26/2017] [Accepted: 11/07/2017] [Indexed: 11/28/2022]
Abstract
Objective: To evaluate fracture strength of veneered translucent zirconium dioxide crowns designed with different porcelain layer thicknesses. Materials and Methods: Sixty crowns, divided into six groups of 10, were used in this study. Groups were divided according to different thicknesses of porcelain veneer on translucent zirconium dioxide cores of equal thickness (0.5 mm). Porcelain thicknesses were 2.5, 2.0, 1.0, 0.8, 0.5 and 0.3 mm. Crowns were artificially aged before loaded to fracture. Determination of fracture mode was performed using light microscope. Results: Group 1.0 mm showed significantly (p ≤ .05) highest fracture loads (mean 1540 N) in comparison with groups 2.5, 2.0 and 0.3 mm (mean 851, 910 and 1202 N). There was no significant difference (p>.05) in fracture loads among groups 1.0, 0.8 and 0.5 mm (mean 1540, 1313 and 1286 N). There were significantly (p ≤ .05) more complete fractures in group 0.3 mm compared to all other groups which presented mainly cohesive fractures. Conclusions: Translucent zirconium dioxide crowns can be veneered with minimal thickness layer of 0.5 mm porcelain without showing significantly reduced fracture strength compared to traditionally veneered (1.0–2.0 mm) crowns. Fracture strength of micro-veneered crowns with a layer of porcelain (0.3 mm) is lower than that of traditionally veneered crowns but still within range of what may be considered clinically sufficient. Porcelain layers of 2.0 mm or thicker should be used where expected loads are low only.
Collapse
Affiliation(s)
- Fahad Bakitian
- Department of Materials Science and Technology, Faculty of Odontology, Malmö UniversityMalmöSweden.,Department of Restorative Dentistry, Faculty of Dentistry, Umm Al-Qura UniversityMakkahSaudi Arabia
| | | | - Evaggelia Papia
- Department of Materials Science and Technology, Faculty of Odontology, Malmö UniversityMalmöSweden
| | - Christel Larsson
- Department of Materials Science and Technology, Faculty of Odontology, Malmö UniversityMalmöSweden
| | - Per Vult von Steyern
- Department of Materials Science and Technology, Faculty of Odontology, Malmö UniversityMalmöSweden
| |
Collapse
|
73
|
Nawafleh NA, Hatamleh MM, Öchsner A, Mack F. Fracture load and survival of anatomically representative monolithic lithium disilicate crowns with reduced tooth preparation and ceramic thickness. J Adv Prosthodont 2017; 9:416-422. [PMID: 29279760 PMCID: PMC5741444 DOI: 10.4047/jap.2017.9.6.416] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 06/17/2017] [Accepted: 07/04/2017] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To investigate the effect of reducing tooth preparation and ceramic thickness on fracture resistance of lithium disilicate crowns. MATERIALS AND METHODS Specimen preparation included a standard complete crown preparation of a typodont mandibular left first molar with an occlusal reduction of 2 mm, proximal/axial wall reduction of 1.5 mm, and 1.0 mm deep chamfer (Group A). Another typodont mandibular first molar was prepared with less tooth reduction: 1 mm occlusal and proximal/axial wall reduction and 0.8 mm chamfer (Group B). Twenty crowns were milled from each preparation corresponding to control group (n=5) and conditioned group of simultaneous thermal and mechanical loading in aqueous environment (n=15). All crowns were then loaded until fracture to determine the fracture load. RESULTS The mean (SD) fracture load values (in Newton) for Group A were 2340 (83) and 2149 (649), and for Group B, 1752 (134) and 1054 (249) without and with fatigue, respectively. Reducing tooth preparation thickness significantly decreased fracture load of the crowns at baseline and after fatigue application. After fatigue, the mean fracture load statistically significantly decreased (P<.001) in Group B; however, it was not affected (P>.05) in Group A. CONCLUSION Reducing the amount of tooth preparation by 0.5 mm on the occlusal and proximal/axial wall with a 0.8 mm chamfer significantly reduced fracture load of the restoration. Tooth reduction required for lithium disilicate crowns is a crucial factor for a long-term successful application of this all-ceramic system.
Collapse
Affiliation(s)
- Noor A Nawafleh
- School of Dentistry and Oral Health, Griffith University, Gold Coast, Australia.,Faculty of Applied Medical Sciences, Jordan University of Science and technology, Irbid, Jordan
| | - Muhanad M Hatamleh
- Maxillofacial Department, King's College Hospital NHS Foundation Trust, London, UK
| | - Andreas Öchsner
- School of engineering, Griffith University, Gold Coast, Australia
| | - Florian Mack
- School of Dentistry and Oral Health, Griffith University, Gold Coast, Australia
| |
Collapse
|
74
|
Choi S, Yoon HI, Park EJ. Load-bearing capacity of various CAD/CAM monolithic molar crowns under recommended occlusal thickness and reduced occlusal thickness conditions. J Adv Prosthodont 2017; 9:423-431. [PMID: 29279761 PMCID: PMC5741445 DOI: 10.4047/jap.2017.9.6.423] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 04/19/2017] [Accepted: 04/20/2017] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The goal of this study was to evaluate the fracture resistances of various monolithic crowns fabricated by computer-aided design and computer-aided manufacturing (CAD/CAM) with different thickness. MATERIALS AND METHODS Test dies were fabricated as mandibular molar forms with occlusal reductions using CAD/CAM. With different occlusal thickness (1.0 or 1.5 mm), a polymer-infiltrated ceramic network (Enamic, EN), and zirconia-reinforced lithium silicate (Suprinity, SU and Celtra-Duo, CD) were used to fabricate molar crowns. Lithium disilicate (e.max CAD, EM) crowns (occlusal: 1.5 mm) were fabricated as control. Seventy crowns (n=10 per group) were bonded to abutments and stored in water for 24 hours. A universal testing machine was used to apply load to crown until fracture. The fractured specimens were examined with a scanning electron microscopy. RESULTS The type of ceramics and the occlusal thickness showed a significant interaction. With a recommended thickness (1.5 mm), the SU revealed the mean load similar to the EM, higher compared with those of the EN and CD. The fracture loads in a reduced thickness (1.0 mm) were similar among the SU, CD, and EN. The mean fracture load of the SU and CD enhanced significantly when the occlusal thickness increased, whereas that of the EN did not. CONCLUSION The fracture loads of monolithic crowns were differently influenced by the changes in occlusal thickness, depending on the type of ceramics. Within the limitations of this study, all the tested crowns withstood the physiological masticatory loads both at the recommended and reduced occlusal
thickness.
Collapse
Affiliation(s)
- Sulki Choi
- Graduate School of Clinical Dentistry, Ewha Womans University, Seoul, Republic of Korea
| | - Hyung-In Yoon
- Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Eun-Jin Park
- Department of Prosthodontics, School of Medicine, Ewha Womans University, Seoul, Republic of Korea
| |
Collapse
|
75
|
Al Shobber MZ, Alkhadra TA. Fracture resistance of different primary anterior esthetic crowns. Saudi Dent J 2017; 29:179-184. [PMID: 29033529 PMCID: PMC5634802 DOI: 10.1016/j.sdentj.2017.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/25/2017] [Accepted: 07/30/2017] [Indexed: 11/07/2022] Open
Abstract
Purpose Investigate and compare fracture resistance of four commercially available esthetic crowns. Methods Sixty-four anterior crowns were used: NuSmile Primary crowns (NuSmile, Houston, Tex. USA) (16); Preveneered Cheng Crowns, (Orthodontic Technologies Inc., Houston, TX) (16); NuSmile ZR (NuSmile, Houston, Tex. USA); and Cheng Crowns zirconia (Orthodontic Technologies Inc., Houston, TX). Crowns were mounted and cemented on a negative replica and placed under servo hydraulic mechanical universal testing machine. Force was applied at 90° with crosshead speed of 1 mm/min until they fractured. Maximum breaking loads were recorded. Data was then analyzed using software that measured the fracture resistance of the crowns. One-way Analysis of Variance (ANOVA) was used to find the differences between the groups and Scheffe post hoc test was used for intergroup comparisons. The level of significance was set as p ≤ 0.05. Results Mean maximum loads were as follows: NuSmile ZR crowns (937.36 + 131.68 N), Cheng Zirconia Crowns (751.43 + 102.103 N), NuSmile Primary crowns (482.37 + 76.92), and Preveneered Cheng Crowns (415.57 + 12.28). Zirconia crowns the had highest fracture resistance compared to preveneered crowns (p < 0.05). No significant difference between NuSmile ZR Zirconia and Cheng Crowns zirconia nor between NuSmile primary Preveenered and Preveneered Cheng Crowns. Conclusion Zirconia crowns showed the highest fracture resistance with NuSmile zirconia crowns to being able to resist fracture even under intense pressure of load compared to Cheng Crowns zirconia.
Collapse
Affiliation(s)
- Manar Zaki Al Shobber
- Department of Pediatric Dentistry and Orthodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Thamer A Alkhadra
- Department of Pediatric Dentistry and Orthodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| |
Collapse
|
76
|
Gumus HS, Polat NT, Yildirim G. Evaluation of fracture resistance of inlay-retained fixed partial dentures fabricated with different monolithic zirconia materials. J Prosthet Dent 2017; 119:959-964. [PMID: 28965678 DOI: 10.1016/j.prosdent.2017.06.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 06/20/2017] [Accepted: 06/21/2017] [Indexed: 10/18/2022]
Abstract
STATEMENT OF PROBLEM Data are lacking on the fracture resistance of monolithic zirconia inlay-retained fixed partial dentures as a conservative treatment for a single missing tooth. PURPOSE The purpose of this in vitro study was to evaluate the fracture resistance of inlay-retained fixed partial dentures produced from 3 different monolithic zirconia materials and based on 2 preparation types and applications with and without thermocycling. MATERIAL AND METHODS A model with missing right and left mandibular first molars was used for different cavity preparations. A tube-shaped cavity and a box-shaped cavity were prepared. Seventy-two epoxy resin casts were prepared from an additional silicone impression. Twenty-four inlay-retained fixed partial dentures from each monolithic zirconia material (Prettau, Zirkonzahn; Katana, Noritake; and Copran, Whitepeaks) were fabricated for each preparation type and cemented to their epoxy model with dual-polymerizing adhesive resin cement; 50% of all specimens were thermocycled for 10000 cycles. The specimens were subjected to a fracture resistance test using a universal testing machine with a crosshead speed of 0.5 mm/min. Fracture surfaces were examined with scanning electron microscopy (SEM), and a specimen from each group was examined for structural changes with differential thermal analysis (DTA). RESULTS No statistically significant differences in terms of fracture resistance were found among brands with both cavity designs and with and without thermal cycles (P>.05). However, SEM and DTA results showed some changes in monolithic zirconia structure after 1 year of aging. CONCLUSIONS The brands and cavity preparation types for single posterior tooth loss generated similar fracture resistance.
Collapse
Affiliation(s)
| | - Nilufer Tulin Polat
- Professor, Department of Prosthodontics, Faculty of Dentistry, Inonu University, Malatya, Turkey
| | - Guler Yildirim
- Assistant Professor, Department of Prosthodontics, Faculty of Dentistry, Inonu University, Malatya, Turkey.
| |
Collapse
|
77
|
Schriwer C, Skjold A, Gjerdet NR, Øilo M. Monolithic zirconia dental crowns. Internal fit, margin quality, fracture mode and load at fracture. Dent Mater 2017; 33:1012-1020. [PMID: 28662859 DOI: 10.1016/j.dental.2017.06.009] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 05/18/2017] [Accepted: 06/13/2017] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Dental all-ceramic restorations of zirconia, with and without an aesthetic veneering layer, have become a viable alternative to conventional metal-ceramic restorations. The aim of this study was to evaluate whether factors of the production methods or the material compositions affect load at fracture, fracture modes, internal fit or crown margins of monolithic zirconia crowns. METHODS Sixty crowns made from six different commercially available dental zirconias were produced to a model tooth with a shallow circumferential chamfer preparation. Internal fit was assessed by the replica method. The crown margin quality was assessed by light microscopy on an ordinal scale. The cemented crowns were loaded centrally in the occlusal fossa with a horizontal steel cylinder with a diameter of 13mm at 0.5mm/min until fracture. Fractographic analysis was performed on the fractured crowns. RESULTS There were statistically significant differences among the groups regarding crown margins, internal fit and load at fracture (p<0.05, Kruskall Wallis). Fracture analyses revealed that all fractures started cervically and propagated to the occlusal surface similar to clinically observed fractures. There was statistically significant correlation between margin quality and load at fracture (Spearman's rank correlation, p<0,05). SIGNIFICANCE Production method and material composition of monolithic zirconia crowns affect internal fit, crown margin quality and the load at fracture. The hard-machined Y-TZP zirconia crowns had the best margin quality and the highest load at fracture. Reduction of margin flaws will improve fracture strength of monolithic zirconia crowns and thereby increase clinical success.
Collapse
Affiliation(s)
- Christian Schriwer
- Department of Clinical Dentistry, Faculty of Medicine and Dentistry, University of Bergen, Norway.
| | - Anneli Skjold
- Department of Clinical Dentistry, Faculty of Medicine and Dentistry, University of Bergen, Norway
| | - Nils Roar Gjerdet
- Department of Clinical Dentistry, Faculty of Medicine and Dentistry, University of Bergen, Norway
| | - Marit Øilo
- Department of Clinical Dentistry, Faculty of Medicine and Dentistry, University of Bergen, Norway
| |
Collapse
|
78
|
Nordahl N, Vult von Steyern P, Larsson C. Fracture strength of ceramic monolithic crown systems of different thickness. J Oral Sci 2017; 57:255-61. [PMID: 26369491 DOI: 10.2334/josnusd.57.255] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
The objective of this study was to evaluate fracture strength of high-translucent (HTZ) and low-translucent (LTZ) zirconia and glass-ceramic (LDS) crowns. HTZ and LTZ crowns were made with thicknesses of; 0.3 mm, 0.5 mm, 0.7 mm, 1.0 mm, and 1.5 mm; and LDS crowns of 1.0 mm and 1.5 mm thicknesses. Each group consisted of 10 crowns. All crowns underwent artificial aging before loading until fracture. Mean fracture strengths varied from 450 N to 3,248 N in the LTZ group, 438 N to 3,487 N in the HTZ group, and 1,030 N to 1,431 N in the LDS group. The load at fracture of HTZ and LTZ crowns was equal. The load at fracture of yttria-stabilized tetragonal zirconia polycrystals crowns was significantly greater than LDS crowns (P = 0.000). Two types of fractures were recorded; complete and partial crack-like fracture. The crack type fracture occurred most frequently in all groups except in the thicker LTZ groups (1.0 mm and 1.5 mm). According to this study, there is no difference in strength between crowns made of high-translucent or low-translucent zirconia. At equal thickness, the strength of zirconia crowns was significantly greater than that of lithium-disilicate glass-ceramic.
Collapse
Affiliation(s)
- Niklas Nordahl
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University
| | | | | |
Collapse
|
79
|
Elshiyab SH, Nawafleh N, George R. Survival and testing parameters of zirconia-based crowns under cyclic loading in an aqueous environment: A systematic review. ACTA ACUST UNITED AC 2017; 8. [DOI: 10.1111/jicd.12261] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 01/07/2017] [Indexed: 01/08/2023]
Affiliation(s)
- Shareen Hayel Elshiyab
- School of Dentistry and Oral Health; Griffith University; Gold Coast Qld Australia
- Faculty of Applied Medical Sciences; Jordan University of Science and Technology; Irbid Jordan
| | - Noor Nawafleh
- School of Dentistry and Oral Health; Griffith University; Gold Coast Qld Australia
- Faculty of Applied Medical Sciences; Jordan University of Science and Technology; Irbid Jordan
| | - Roy George
- School of Dentistry and Oral Health; Griffith University; Gold Coast Qld Australia
| |
Collapse
|
80
|
Amaral M, Villefort RF, Melo RM, Pereira GKR, Zhang Y, Valandro LF, Bottino MA. Fatigue limit of monolithic Y-TZP three-unit-fixed dental prostheses: Effect of grinding at the gingival zone of the connector. J Mech Behav Biomed Mater 2017; 72:159-162. [PMID: 28494273 DOI: 10.1016/j.jmbbm.2017.03.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 03/03/2017] [Accepted: 03/05/2017] [Indexed: 11/19/2022]
Abstract
OBJECTIVES To determine the fatigue limits of three-unit monolithic zirconia fixed dental prosthesis (FDPs) before and after grinding of the gingival areas of connectors with diamond burs. MATERIAL AND METHODS FDPs were milled from pre-sintered blocks of zirconia simulating the absence of the first mandibular molar. Half of the specimens were subjected to grinding, simulating clinical adjustment, and all of them were subjected to glazing procedure. Additional specimens were manufactured for roughness analysis. FDPs were adhesively cemented onto glass-fiber reinforced epoxy resin abutments. Fatigue limits and standard deviations were obtained using a staircase fatigue method (n=20, 100,000 loading cycles/5Hz). The initial test load was 70% of the mean load-to-fracture (n=3) and load increments were 5% of the initial test load for both the control and ground specimens. Data were compared by Student's T-test (α≤0.05). RESULTS Both the control and ground groups exhibited similar values of load-to-fracture and fatigue limits. Neither the surface treatments nor ageing affected the surface roughness of the specimens. CONCLUSIONS The damage induced by grinding with fine-grit diamond bur in the gingival area of the connectors did not decrease the fatigue limit of the three-unit monolithic zirconia FDP.
Collapse
Affiliation(s)
- Marina Amaral
- Department of Dentistry, Dental Prosthesis, University of Taubate, Taubaté, São Paulo State, Brazil
| | - Regina F Villefort
- Post Graduation Program in Restorative Dentistry (Prosthetic Dentistry Unit), School of Dentistry, Sao Paulo State University, São José dos Campos, São Paulo State, Brazil
| | - Renata Marques Melo
- Post Graduation Program in Restorative Dentistry, School of Dentistry, Sao Paulo State University, São José dos Campos, São Paulo State, Brazil
| | - Gabriel K R Pereira
- Post Graduation Program in Dental Sciences, School of Dentistry, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil
| | - Yu Zhang
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, 433 First Avenue, New York, NY, USA
| | - Luiz Felipe Valandro
- Department of Restorative Dentistry, School of Dentistry, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil.
| | - Marco Antonio Bottino
- Department of Dental Materials and Prosthesis, School of Dentistry, Sao Paulo State University, São José dos Campos, São Paulo State, Brazil
| |
Collapse
|
81
|
Lundberg K, Wu L, Papia E. The effect of grinding and/or airborne-particle abrasion on the bond strength between zirconia and veneering porcelain: a systematic review. ACTA BIOMATERIALIA ODONTOLOGICA SCANDINAVICA 2017. [PMID: 28642927 PMCID: PMC5463334 DOI: 10.1080/23337931.2017.1293486] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Objective: The aim of the study was to make an inventory of current literature on the bond strength between zirconia and veneering porcelain after surface treatment of zirconia by grinding with diamond bur and/or with airborne-particle abrasion. Material and methods: The literature search for the present review was made following recommended guidelines using acknowledged methodology on how to do a systematic review. The electronic databases PubMed, Cochrane Library, and Science Direct were used in the present study. Results: Twelve studies were selected. Test methods used in the original studies included shear bond strength (SBS) test, tensile bond strength test, and micro-tensile bond strength test. The majority of studies used SBS. Results showed a large variation within each surface treatment of zirconia, using different grain size, blasting time, and pressure. Conclusions: Airborne-particle abrasion might improve the bond strength and can therefore be considered a feasible surface treatment for zirconia that is to be bonded. Grinding has been recommended as a surface treatment for zirconia to improve the bond strength; however, this recommendation cannot be verified. A standardized test method and surface treatment are required to be able to compare the results from different studies and draw further conclusions.
Collapse
Affiliation(s)
- Karin Lundberg
- Department of Materials Science and Technology, Faculty of Odontology, Malmö UniversityMalmöSweden
| | - Lindsey Wu
- Department of Materials Science and Technology, Faculty of Odontology, Malmö UniversityMalmöSweden
| | - Evaggelia Papia
- Department of Materials Science and Technology, Faculty of Odontology, Malmö UniversityMalmöSweden
| |
Collapse
|
82
|
The substitution of the implant and abutment for their analogs in mechanical studies: In vitro and in silico analysis. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2017; 75:50-54. [PMID: 28415491 DOI: 10.1016/j.msec.2017.02.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 12/01/2016] [Accepted: 02/07/2017] [Indexed: 11/20/2022]
Abstract
The use of analogs could reduce the cost of mechanical tests involving implant-supported crowns, but it is unclear if it would negatively affect the data accuracy. This study evaluated the substitution of the implant by implants analogs or abutment analogs as a support for crowns in mechanical tests, taking into account stress distribution and fracture load of monolithic lithium disilicate crowns. Thirty lithium disilicate monolithic crowns were randomized into three groups according to the set: Implant+abutment (IA); implant analog+abutment (IAA); abutment analog (AA). The specimens were subjected to mechanical fatigue (106cycles, 200N, 2Hz) and thermal fatigue (104cycles, 5°-55°C). A final compression load was applied and the maximum fracture load was recorded. Data were analyzed using one-way ANOVA (α=0.05). The experiment was validated by finite element analysis and the maximum principal stress was recorded. No statistically significant difference was observed in the mean fracture load among groups (P>0.05). The failure mode was similar for all groups with the origin of crack propagation located at the load point application. Finite element analysis showed similar stress distribution and stress peak values for all groups. The use of implant's or abutment's analog does not influence the fracture load and stress distribution for cemented implant-supported crowns.
Collapse
|
83
|
Bankoğlu Güngör M, Karakoca Nemli S, Çağlar A, Aydın C, Yılmaz H. Clinical study on the success of posterior monolithic zirconia crowns and fixed dental prostheses: preliminary report. ACTA ODONTOLOGICA TURCICA 2017. [DOI: 10.17214/gaziaot.286916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
84
|
Effects of two grading techniques of zirconia material on the fatigue limit of full-contour 3-unit fixed dental prostheses. Dent Mater 2017; 33:e155-e164. [PMID: 28118929 DOI: 10.1016/j.dental.2016.12.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 12/15/2016] [Accepted: 12/16/2016] [Indexed: 11/20/2022]
Abstract
OBJECTIVE This study evaluated the effects of two grading techniques of zirconia material on the fatigue limit of full-contour 3-unit fixed dental prostheses (FDPs). METHODS Presintered blocks of 3Y-TZP were milled to obtain sixty-nine 3-unit FDPs, which were divided into three groups (n=23). The control group (CTL) was sintered and glazed following manufacturer's instructions. In the two experimental groups presintered FDPs received a surface silica/glass infiltration treatment before the sintering process. Silica sol-gel group (SSG) was graded by the sol-gel processing route, while the glass-zirconia-glass group (GZG) was graded by an enameling technique. Graded groups did not receive a glaze layer after sintering. All FDPs were then luted with a dual-curing resin cement on composite abutments, embedded in polyurethane and stored in water for five days. The initial load of the fatigue test was calculated based on the results of the monotonic testing applied on three specimens of each group. To determine the fatigue limit, 20 samples of each group were subjected to staircase testing (100,000 cycles/5Hz). RESULTS The fatigue limits (in Newtons) were CTL=1607.27, SSG=1824.31, and GZG=2006.57, and the Dixon and Mood test indicated statistically significant differences among groups (95% confidence interval) (GZG > SSG > CTL). SIGNIFICANCE The infiltration of silica and glass on bulk zirconia, by two different grading methods, increased the fatigue limits of monolithic zirconia FDPs.
Collapse
|
85
|
Lee WF, Feng SW, Lu YJ, Wu HJ, Peng PW. Effects of two surface finishes on the color of cemented and colored anatomic-contour zirconia crowns. J Prosthet Dent 2016; 116:264-8. [DOI: 10.1016/j.prosdent.2015.12.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 12/24/2015] [Accepted: 12/28/2015] [Indexed: 11/29/2022]
|
86
|
Malkondu Ö, Tinastepe N, Akan E, Kazazoğlu E. An overview of monolithic zirconia in dentistry. BIOTECHNOL BIOTEC EQ 2016. [DOI: 10.1080/13102818.2016.1177470] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Özlem Malkondu
- Faculty of Dentistry, Department of Prosthodontics, Yeditepe University, Istanbul, Turkey
| | - Neslihan Tinastepe
- Faculty of Dentistry, Department of Prosthodontics, Yeditepe University, Istanbul, Turkey
| | - Ender Akan
- Faculty of Dentistry, Department of Prosthodontics, İzmir Katip Çelebi University, Izmir, Turkey
| | - Ender Kazazoğlu
- Faculty of Dentistry, Department of Prosthodontics, İzmir Katip Çelebi University, Izmir, Turkey
| |
Collapse
|
87
|
Nawafleh N, Hatamleh MM, Öchsner A, Mack F. The Impact of Core/Veneer Thickness Ratio and Cyclic Loading on Fracture Resistance of Lithium Disilicate Crown. J Prosthodont 2016; 27:75-82. [PMID: 26965298 DOI: 10.1111/jopr.12473] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/29/2015] [Indexed: 11/28/2022] Open
Affiliation(s)
- Noor Nawafleh
- School of Dentistry and Oral Health, Griffith University, Queensland, Australia
| | - Muhanad M Hatamleh
- Cranio-Maxillofacial Prosthetics Unit, King's College Hospital NHS Foundation Trust, London, UK
| | - Andreas Öchsner
- School of Engineering, Griffith University, Queensland, Australia
| | - Florian Mack
- School of Dentistry and Oral Health, Griffith University, Queensland, Australia
| |
Collapse
|
88
|
Schatz C, Strickstrock M, Roos M, Edelhoff D, Eichberger M, Zylla IM, Stawarczyk B. Influence of Specimen Preparation and Test Methods on the Flexural Strength Results of Monolithic Zirconia Materials. MATERIALS 2016; 9:ma9030180. [PMID: 28773307 PMCID: PMC5456702 DOI: 10.3390/ma9030180] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/09/2016] [Accepted: 03/02/2016] [Indexed: 11/16/2022]
Abstract
The aim of this work was to evaluate the influence of specimen preparation and test method on the flexural strength results of monolithic zirconia. Different monolithic zirconia materials (Ceramill Zolid (Amann Girrbach, Koblach, Austria), Zenostar ZrTranslucent (Wieland Dental, Pforzheim, Germany), and DD Bio zx2 (Dental Direkt, Spenge, Germany)) were tested with three different methods: 3-point, 4-point, and biaxial flexural strength. Additionally, different specimen preparation methods were applied: either dry polishing before sintering or wet polishing after sintering. Each subgroup included 40 specimens. The surface roughness was assessed using scanning electron microscopy (SEM) and a profilometer whereas monoclinic phase transformation was investigated with X-ray diffraction. The data were analyzed using a three-way Analysis of Variance (ANOVA) with respect to the three factors: zirconia, specimen preparation, and test method. One-way ANOVA was conducted for the test method and zirconia factors within the combination of two other factors. A 2-parameter Weibull distribution assumption was applied to analyze the reliability under different testing conditions. In general, values measured using the 4-point test method presented the lowest flexural strength values. The flexural strength findings can be grouped in the following order: 4-point < 3-point < biaxial. Specimens prepared after sintering showed significantly higher flexural strength values than prepared before sintering. The Weibull moduli ranged from 5.1 to 16.5. Specimens polished before sintering showed higher surface roughness values than specimens polished after sintering. In contrast, no strong impact of the polishing procedures on the monoclinic surface layer was observed. No impact of zirconia material on flexural strength was found. The test method and the preparation method significantly influenced the flexural strength values.
Collapse
Affiliation(s)
- Christine Schatz
- Department of Prosthodontics, Dental School, Ludwig-Maximilians-University Munich, Goethestrasse 70, Munich 80336, Germany.
| | - Monika Strickstrock
- Faculty of Engineering and Computer Science, Material Science and Analysis, University of Applied Sciences, Hochschule Osnabrück, Albrechtstrasse 30, Osnabrück 49076, Germany.
| | - Malgorzata Roos
- Department of Biostatistics, Epidemiology Biostatistics and Prevention Institute, University of Zurich, Hirschengraben 84, Zurich 8001, Switzerland.
| | - Daniel Edelhoff
- Department of Prosthodontics, Dental School, Ludwig-Maximilians-University Munich, Goethestrasse 70, Munich 80336, Germany.
| | - Marlis Eichberger
- Department of Prosthodontics, Dental School, Ludwig-Maximilians-University Munich, Goethestrasse 70, Munich 80336, Germany.
| | - Isabella-Maria Zylla
- Faculty of Engineering and Computer Science, Material Science and Analysis, University of Applied Sciences, Hochschule Osnabrück, Albrechtstrasse 30, Osnabrück 49076, Germany.
| | - Bogna Stawarczyk
- Department of Prosthodontics, Dental School, Ludwig-Maximilians-University Munich, Goethestrasse 70, Munich 80336, Germany.
| |
Collapse
|
89
|
Bergamo E, da Silva WJ, Cesar PF, Del Bel Cury AA. Fracture Load and Phase Transformation of Monolithic Zirconia Crowns Submitted to Different Aging Protocols. Oper Dent 2016; 41:E118-E130. [PMID: 26918927 DOI: 10.2341/15-154-l] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Monolithic zirconia crowns have many favorable properties and may potentially be used to solve dental problems such as chipping. However, monolithic zirconia crown resistance can be affected by its phase transformation when subjected to low temperatures, humidity, and stress. This study evaluated the fracture load and phase transformation of monolithic zirconia crowns submitted to different thermal and mechanical aging tests. Seventy monolithic zirconia crowns were randomly divided into the following five groups: control, no treatment; hydrothermal aging at 122°C, two bar for one hour; thermal fatigue, 104 cycles between 5°C and 55°C, dwell time, 30 seconds; and mechanical fatigue, 106 cycles with a load of 70 N, sliding of 1.5 mm at 1.4 Hz; and combination of mechanical plus thermal fatigue. Fracture load was measured with a universal testing machine. Surface changes and fracture mode and origin were examined with a scanning electron microscope. Monoclinic phase content was evaluated by x-ray diffraction. The fracture load was analyzed using one-way analysis of variance at a level of 5%, and Weibull distribution was performed. No statistically significant differences were observed in the mean fracture load and characteristic fracture load among the groups (p>0.05). The Weibull modulus ranged from 6.2 to 16.6. The failure mode was similar for all groups with the crack origin located at the contact point of the indenter. Phase transformation was shown at different surfaces of the crown in all groups (1.9% to 8.9%). In conclusion, monolithic zirconia crowns possess high fracture load, structural reliability, and low phase transformation.
Collapse
|
90
|
Mahmood DJH, Linderoth EH, Wennerberg A, Vult Von Steyern P. Influence of core design, production technique, and material selection on fracture behavior of yttria-stabilized tetragonal zirconia polycrystal fixed dental prostheses produced using different multilayer techniques: split-file, over-pressing, and manually built-up veneers. Clin Cosmet Investig Dent 2016; 8:15-27. [PMID: 26929667 PMCID: PMC4758792 DOI: 10.2147/ccide.s94343] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
AIM To investigate and compare the fracture strength and fracture mode in eleven groups of currently, the most commonly used multilayer three-unit all-ceramic yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) fixed dental prostheses (FDPs) with respect to the choice of core material, veneering material area, manufacturing technique, design of connectors, and radii of curvature of FDP cores. MATERIALS AND METHODS A total of 110 three-unit Y-TZP FDP cores with one intermediate pontic were made. The FDP cores in groups 1-7 were made with a split-file design, veneered with manually built-up porcelain, computer-aided design-on veneers, and over-pressed veneers. Groups 8-11 consisted of FDPs with a state-of-the-art design, veneered with manually built-up porcelain. All the FDP cores were subjected to simulated aging and finally loaded to fracture. RESULTS There was a significant difference (P<0.05) between the core designs, but not between the different types of Y-TZP materials. The split-file designs with VITABLOCS(®) (1,806±165 N) and e.max(®) ZirPress (1,854±115 N) and the state-of-the-art design with VITA VM(®) 9 (1,849±150 N) demonstrated the highest mean fracture values. CONCLUSION The shape of a split-file designed all-ceramic reconstruction calls for a different dimension protocol, compared to traditionally shaped ones, as the split-file design leads to sharp approximal indentations acting as fractural impressions, thus decreasing the overall strength. The design of a framework is a crucial factor for the load bearing capacity of an all-ceramic FDP. The state-of-the-art design is preferable since the split-file designed cores call for a cross-sectional connector area at least 42% larger, to have the same load bearing capacity as the state-of-the-art designed cores. All veneering materials and techniques tested in the study, split-file, over-press, built-up porcelains, and glass-ceramics are, with a great safety margin, sufficient for clinical use both anteriorly and posteriorly. Analysis of the fracture pattern shows differences between the milled veneers and over-pressed or built-up veneers, where the milled ones show numerically more veneer cracks and the other groups only show complete connector fractures.
Collapse
Affiliation(s)
| | - Ewa H Linderoth
- Department of Prosthetic Dentistry, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - Ann Wennerberg
- Department of Prosthetic Dentistry, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - Per Vult Von Steyern
- Department of Prosthetic Dentistry, Faculty of Odontology, Malmö University, Malmö, Sweden
| |
Collapse
|
91
|
Zhang Y, Mai Z, Barani A, Bush M, Lawn B. Fracture-resistant monolithic dental crowns. Dent Mater 2016; 32:442-9. [PMID: 26792623 DOI: 10.1016/j.dental.2015.12.010] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 10/30/2015] [Accepted: 12/07/2015] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To quantify the splitting resistance of monolithic zirconia, lithium disilicate and nanoparticle-composite dental crowns. METHODS Fracture experiments were conducted on anatomically-correct monolithic crown structures cemented to standard dental composite dies, by axial loading of a hard sphere placed between the cusps. The structures were observed in situ during fracture testing, and critical loads to split the structures were measured. Extended finite element modeling (XFEM), with provision for step-by-step extension of embedded cracks, was employed to simulate full failure evolution. RESULTS Experimental measurements and XFEM predictions were self-consistent within data scatter. In conjunction with a fracture mechanics equation for critical splitting load, the data were used to predict load-sustaining capacity for crowns on actual dentin substrates and for loading with a sphere of different size. Stages of crack propagation within the crown and support substrate were quantified. Zirconia crowns showed the highest fracture loads, lithium disilicate intermediate, and dental nanocomposite lowest. Dental nanocomposite crowns have comparable fracture resistance to natural enamel. SIGNIFICANCE The results confirm that monolithic crowns are able to sustain high bite forces. The analysis indicates what material and geometrical properties are important in optimizing crown performance and longevity.
Collapse
Affiliation(s)
- Yu Zhang
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY 10010, USA.
| | - Zhisong Mai
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY 10010, USA
| | - Amir Barani
- School of Mechanical and Chemical Engineering, University of Western Australia, Crawley, WA 6009, Australia
| | - Mark Bush
- School of Mechanical and Chemical Engineering, University of Western Australia, Crawley, WA 6009, Australia
| | - Brian Lawn
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| |
Collapse
|
92
|
Nakamura K, Harada A, Ono M, Shibasaki H, Kanno T, Niwano Y, Adolfsson E, Milleding P, Örtengren U. Effect of low-temperature degradation on the mechanical and microstructural properties of tooth-colored 3Y-TZP ceramics. J Mech Behav Biomed Mater 2016; 53:301-311. [DOI: 10.1016/j.jmbbm.2015.08.031] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 08/20/2015] [Accepted: 08/24/2015] [Indexed: 02/04/2023]
|
93
|
Nawafleh N, Hatamleh M, Elshiyab S, Mack F. Lithium Disilicate Restorations Fatigue Testing Parameters: A Systematic Review. J Prosthodont 2015; 25:116-26. [PMID: 26505638 DOI: 10.1111/jopr.12376] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2015] [Indexed: 11/29/2022] Open
Abstract
PURPOSE To review laboratory studies that investigated fatigue resistance of lithium disilicate (LD) crowns and fixed dental prostheses (FDPs) to elucidate study designs and testing parameters. METHODS An electronic search was performed in PubMed, Scopus, and Ovid to identify in vitro studies that investigated fatigue resistance of LD crowns and FDPs. The search included all studies published in English in peer-reviewed journals in the period from 1998 to June 2014. The search followed a specific strategy that included combination of the following keywords: lithium disilicate, e.max, empress, all-ceramic, all ceramic, glass ceramic, fatigue, cyclic loading, dynamic loading, chewing simulator, fracture resistance, thermocycling, laboratory simulation, aging, crown, FDPs, FPDs, fixed partial denture, fixed dental prosthesis, and bridge. Studies were selected if mechanical and thermal loading parameters were clearly identified. Search results with abstracts were transferred into Endnote reference system, and duplicates were deleted. The remaining studies were then reviewed at three levels (title, abstract, full text) to further refine the articles. RESULTS The initial search retrieved 1044 eligible studies. After deduplication, 864 records were examined by titles and then abstracts; 826 were excluded, and 38 were assessed by full-text reading. In total, 19 articles met inclusion criteria and were included in this study. CONCLUSION The studies reviewed showed a level of heterogeneity, as testing parameters were considered through different setups. The current study demonstrated that various setting of the testing parameters and having a lack of testing standardization has likely led to inconsistency in the reported results. The obvious heterogeneity in the setting of testing variables-especially the magnitude of load and number of cycles applied-made it impractical to run direct comparisons between the reviewed studies. Therefore, specific international standardization of fatigue testing of dental restorations is urgently needed to ensure the delivery of consistent, indicative, and comparable data.
Collapse
Affiliation(s)
- Noor Nawafleh
- School of Dentistry and Oral Health, Griffith University, Queensland, Australia
| | - Muhanad Hatamleh
- Cranio-Maxillofacial Prosthetics Unit, King's College Hospital NHS Foundation Trust, London, UK
| | - Shareen Elshiyab
- School of Dentistry and Oral Health, Griffith University, Queensland, Australia
| | - Florian Mack
- School of Dentistry and Oral Health, Griffith University, Queensland, Australia
| |
Collapse
|
94
|
Nakamura K, Katsuda Y, Ankyu S, Harada A, Tenkumo T, Kanno T, Niwano Y, Egusa H, Milleding P, Örtengren U. Cutting efficiency of diamond burs operated with electric high-speed dental handpiece on zirconia. Eur J Oral Sci 2015; 123:375-380. [DOI: 10.1111/eos.12211] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2015] [Indexed: 11/27/2022]
Affiliation(s)
- Keisuke Nakamura
- Department of Prosthetic Dentistry/Dental Materials Science; Institute of Odontology; University of Gothenburg; Gothenburg Sweden
- Laboratory for Redox Regulation; Tohoku University Graduate School of Dentistry; Sendai Japan
| | - Yusuke Katsuda
- Division of Molecular and Regenerative Prosthodontics; Tohoku University Graduate School of Dentistry; Sendai Japan
| | - Shuhei Ankyu
- Division of Molecular and Regenerative Prosthodontics; Tohoku University Graduate School of Dentistry; Sendai Japan
| | - Akio Harada
- Division of Molecular and Regenerative Prosthodontics; Tohoku University Graduate School of Dentistry; Sendai Japan
| | - Taichi Tenkumo
- Liaison Center for Innovative Dentistry; Tohoku University Graduate School of Dentistry; Sendai Japan
| | - Taro Kanno
- Division of Molecular and Regenerative Prosthodontics; Tohoku University Graduate School of Dentistry; Sendai Japan
| | - Yoshimi Niwano
- Laboratory for Redox Regulation; Tohoku University Graduate School of Dentistry; Sendai Japan
| | - Hiroshi Egusa
- Division of Molecular and Regenerative Prosthodontics; Tohoku University Graduate School of Dentistry; Sendai Japan
| | - Percy Milleding
- Department of Prosthetic Dentistry/Dental Materials Science; Institute of Odontology; University of Gothenburg; Gothenburg Sweden
| | - Ulf Örtengren
- Department of Prosthetic Dentistry/Dental Materials Science; Institute of Odontology; University of Gothenburg; Gothenburg Sweden
- Department of Clinical Dentistry/Faculty of Health Sciences; The Arctic University of Norway; Tromsø Norway
| |
Collapse
|
95
|
Nakamura K, Harada A, Kanno T, Inagaki R, Niwano Y, Milleding P, Örtengren U. The influence of low-temperature degradation and cyclic loading on the fracture resistance of monolithic zirconia molar crowns. J Mech Behav Biomed Mater 2015; 47:49-56. [DOI: 10.1016/j.jmbbm.2015.03.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 03/08/2015] [Accepted: 03/10/2015] [Indexed: 02/04/2023]
|
96
|
Nakamura K, Harada A, Inagaki R, Kanno T, Niwano Y, Milleding P, Örtengren U. Fracture resistance of monolithic zirconia molar crowns with reduced thickness. Acta Odontol Scand 2015; 73:602-8. [PMID: 25635734 DOI: 10.3109/00016357.2015.1007479] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVES The purpose of the present study was to analyze the relationship between fracture load of monolithic zirconia crowns and axial/occlusal thickness and to evaluate the fracture resistance of monolithic zirconia crowns with reduced thickness in comparison with that of monolithic lithium disilicate crowns with regular thickness. MATERIALS AND METHODS Monolithic zirconia crowns (Lava Plus Zirconia, 3M/ESPE) with specified axial/occlusal thicknesses and lithium disilicate crowns (IPS e.max press, Ivoclar/Vivadent) with regular thickness were fabricated using a dental CAD/CAM system and a press technique, respectively. The crowns cemented onto dies were loaded until fracture. Based on measurements of the crown thickness made by micro-CT and the fracture load, multiple regression analysis was performed. RESULTS It was revealed that the occlusal thickness significantly affected the fracture load (p < 0.01), but the axial thickness did not (p = 0.2828). Although the reduction of the occlusal thickness decreased the fracture resistance of the monolithic zirconia crowns, the fracture load of the zirconia crowns with the occlusal thickness of 0.5 mm (5558 ± 522 N) was significantly higher than that of lithium disilicate crowns with an occlusal thickness of 1.5 mm (3147 ± 409 N). CONCLUSION Within the limitations of the present study, it is suggested that monolithic zirconia crown with chamfer width of 0.5 mm and occlusal thickness of 0.5 mm can be used in the molar region in terms of fracture resistance.
Collapse
Affiliation(s)
- Keisuke Nakamura
- Department of Prosthetic Dentistry/Dental Materials Science, Institute of Odontology, University of Gothenburg , Gothenburg , Sweden
| | | | | | | | | | | | | |
Collapse
|
97
|
|