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Guler MS, Guler C, Belduz Kara N, Odabasi D, Bekci ML. The stress distribution of a primary molar tooth restored with stainless steel crown using different luting cements. BMC Oral Health 2024; 24:269. [PMID: 38395853 PMCID: PMC10893635 DOI: 10.1186/s12903-024-04038-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 02/16/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND The aim of this study is to evaluate the stress distributions of a primary molar tooth restored with a stainless steel crown (SSC) using resin and glass ionomer luting cements by Finite Element Analysis (FEA). METHODS Original DICOM data of a primary molar was used to create a 3D model. One model was prepared as a tooth model with SSC. A 30 μm cement layer was used in model. Two different luting cements were tested in the study: self-cure adhesive resin cement, and glass ionomer cement. Vertical and oblique loads of 330 N were applied to simulate maximum bite force and lateral forces in the occlusal contact areas of the models. Maximum von Mises stress values in the models were evaluated as MPa. RESULTS The maximum von Mises stress value was observed in the force application and general occlusal contact areas for all models. The maximum von Mises stress values were higher in the tooth model with SSC using self-cure adhesive resin cement (478.09 MPa and 214.62 MPa) than in the tooth model with SSC using glass ionomer cement (220.06 MPa and 198.72 MPa) in both vertical and oblique loading, respectively. CONCLUSIONS Depending on the magnitude of the bite force on the SSC, fracture of the luting cement materials could occur if the stress exceeds the endurance limit of the luting cement. Cementation with glass ionomer cement may help to reduce stress levels in SSC restorations of primary molars in children.
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Affiliation(s)
- Mehmet Sami Guler
- Department of Machinery and Metal Technologies, Vocational School of Technical Sciences, Ordu University, Ordu, Turkey
| | - Cigdem Guler
- Department of Pediatric Dentistry, Faculty of Dentistry, Ordu University, Ordu, Turkey
| | - Nihal Belduz Kara
- Department of Pediatric Dentistry, Faculty of Dentistry, Ordu University, Ordu, Turkey
| | - Didem Odabasi
- Department of Pediatric Dentistry, Faculty of Dentistry, Ordu University, Ordu, Turkey.
| | - Muhammed Latif Bekci
- Department of Machinery and Metal Technologies, Vocational School of Technical Sciences, Ordu University, Ordu, Turkey
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Alhamoudi FH, Aldosari LIN, Alshadidi AAF, Hassan SAB, Alwadi MAM, Vaddamanu SK, Cicciù M, Minervini G. An Investigation of the Fracture Loads Involved in the Framework of Removable Partial Dentures Using Two Types of All-Ceramic Restorations. Biomimetics (Basel) 2023; 8:biomimetics8010113. [PMID: 36975343 PMCID: PMC10046878 DOI: 10.3390/biomimetics8010113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 02/21/2023] [Accepted: 03/06/2023] [Indexed: 03/12/2023] Open
Abstract
Retention and support are needed for removable partial denture stability. The stability can be achieved by clasps, occlusal and cingulum rests on healthy abutment teeth. However, implants or crowns can be used to support the removable partial denture instated on unhealthy abutment teeth. This study was conducted to investigate the fracture strength of two types of all-ceramic restorations used as abutments for the removable partial denture framework. The crowns were manufactured with two types of ceramic materials: zirconia and IPS e.max Press ceramics. The metal alloy (cobalt-chrome) was cast to form the removable partial denture framework. A universal testing machine was used to evaluate the fracture strength of both ceramic crown materials. The results presented no fractures in all-ceramic crowns, but deformation of the partial denture frameworks occurred. With the limitation of this study, it can be concluded that zirconia and IPS e.max Press ceramic can be used as abutments to provide adequate support to the removable partial denture.
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Affiliation(s)
- Fahad Hussain Alhamoudi
- Dental Technology Department, College of Applied Medical Science, King Khalid University, Abha 61421, Saudi Arabia
- Correspondence: (F.H.A.); (S.K.V.); (G.M.)
| | - Lujain Ibrahim N. Aldosari
- Department of Prosthetic Dentistry, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia
| | - Abdulkhaliq Ali F. Alshadidi
- Dental Technology Department, College of Applied Medical Science, King Khalid University, Abha 61421, Saudi Arabia
| | - Saeed Awod Bin Hassan
- Department of Restorative Dental Sciences, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia
| | - Maram Ali M. Alwadi
- Dental Health Department, College of Applied Medical Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Sunil Kumar Vaddamanu
- Dental Technology Department, College of Applied Medical Science, King Khalid University, Abha 61421, Saudi Arabia
- Correspondence: (F.H.A.); (S.K.V.); (G.M.)
| | - Marco Cicciù
- Department of General Surgery and Medical-Surgical Specialties, School of Dentistry, University of Catania, 95124 Catania, Italy
| | - Giuseppe Minervini
- Multidisciplinary Department of Medical-Surgical and Odontostomatological Specialties, University of Campania “Luigi Vanvitelli”, 80121 Naples, Italy
- Correspondence: (F.H.A.); (S.K.V.); (G.M.)
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Bonfante EA, Calamita M, Bergamo ETP. Indirect restorative systems-A narrative review. J ESTHET RESTOR DENT 2023; 35:84-104. [PMID: 36688803 DOI: 10.1111/jerd.13016] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 01/24/2023]
Abstract
OBJECTIVE The background and clinical understanding of the properties of currently available indirect restorative systems and fabrication methods is, along with manufacturer and evidence-based literature, an important starting point to guide the clinical selection of materials for tooth and/or implant supported reconstructions. Therefore, this review explores most indirect restorative systems available in the market, especially all-ceramic, along with aspects of manufacturing process, clinical survival rates, and esthetic outcomes. OVERVIEW Progressive incorporation of new technologies in the dental field and advancements in materials science have enabled the development/improvement of indirect restorative systems and treatment concepts in oral rehabilitation, resulting in reliable and predictable workflows and successful esthetic and functional outcomes. Indirect restorative systems have evolved from metal ceramics and polymers to glass ceramics, polycrystalline ceramics, and resin-matrix ceramics, aiming to improve not only biological and mechanical properties, but especially the optical properties and esthetic quality of the reconstructions, in attempt to mimic natural teeth. CONCLUSIONS Based on several clinical research, materials, and patient-related parameters, a decision tree for the selection of indirect restorative materials was suggested to guide clinicians in the rehabilitation process. CLINICAL SIGNIFICANCE The pace of materials development is faster than that of clinical research aimed to support their use. Since no single material provides an ideal solution to every case, professionals must continuously seek information from well designed, long-term clinical trials in order to incorporate or not new materials and technological advancements.
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Affiliation(s)
- Estevam A Bonfante
- Department of Prosthodontics and Periodontology, Bauru School of Dentistry - University of São Paulo, Bauru, SP, Brazil
| | - Marcelo Calamita
- Department of Restorative Dental Sciences at the University of Florida, Gainesville, Florida, USA
| | - Edmara T P Bergamo
- Department of Prosthodontics and Periodontology, Bauru School of Dentistry - University of São Paulo, Bauru, SP, Brazil
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Hinz S, Bensel T, Bömicke W, Henningsen A, Rudolph J, Boeckler AF. Impact of the Veneering Technique and Framework Material on the Failure Loads of All-Ceramic Computer-Aided Design/Computer-Aided Manufacturing Fixed Partial Dentures. MATERIALS 2022; 15:ma15030756. [PMID: 35160701 PMCID: PMC8836578 DOI: 10.3390/ma15030756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/08/2022] [Accepted: 01/15/2022] [Indexed: 02/04/2023]
Abstract
Objectives: Zirconia (Y-TZP) ceramics are considered as posterior fixed partial denture (FPD) materials; however, their applications are limited due to chipping. The use of monolithic lithium disilicate (LiDi) glass ceramics in posterior FPDs can be advantageous. This in vitro study aims to compare the loads until failure of posterior Y-TZP-FPDs and LiDi-FPDs before and after aging.
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Affiliation(s)
- Sebastian Hinz
- Department of Prosthodontics, Martin-Luther-University Halle-Wittenberg, Magdeburgerstraße 16, 06112 Halle, Germany; (J.R.); (A.F.B.)
- Correspondence: (S.H.); (T.B.)
| | - Tobias Bensel
- Department of Prosthodontics, Martin-Luther-University Halle-Wittenberg, Magdeburgerstraße 16, 06112 Halle, Germany; (J.R.); (A.F.B.)
- Correspondence: (S.H.); (T.B.)
| | - Wolfgang Bömicke
- Department of Prosthetic Dentistry, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany;
| | - Anders Henningsen
- Department of Oral and Maxillofacial Surgery, University Hospital Hamburg-Eppendorf, 20246 Hamburg, Germany;
| | - Judith Rudolph
- Department of Prosthodontics, Martin-Luther-University Halle-Wittenberg, Magdeburgerstraße 16, 06112 Halle, Germany; (J.R.); (A.F.B.)
| | - Arne F. Boeckler
- Department of Prosthodontics, Martin-Luther-University Halle-Wittenberg, Magdeburgerstraße 16, 06112 Halle, Germany; (J.R.); (A.F.B.)
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SHAFIGH ELNAZ, ASHRAFI MEHRAN. A REVIEW OF MECHANICAL BEHAVIOR OF DENTAL CERAMIC RESTORATIONS. J MECH MED BIOL 2021. [DOI: 10.1142/s0219519421500639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Dental ceramics are well known for restoring the function and aesthetic of lost or damaged teeth. Understanding these materials’ mechanical and aesthetic properties can make a suitable choice for those materials. The longevity of dental ceramics depends on several factors, including manufacturing method, clinical process, and the oral cavity’s aqueous environment. Failure mechanisms in restorative ceramics are complex and a combination of several factors. Different microstructures in the crystalline phase will involve the propagation of cracks and eventually the fatigue of ceramic materials. Large grains reduce mechanical performance compared to small grain sizes. Aesthetic materials used for veneering are weaker than the core materials and fail when even subjected to small loads. The soft bonding in the core–veneer interface and possible residual stresses created during the veneering method are drawbacks of these systems. Studies on the mechanical behavior of these materials have grown significantly in recent years and provide helpful information about static and fatigue experimentation and the failure behavior of various materials used in dental crowns.
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Affiliation(s)
- ELNAZ SHAFIGH
- Operative Dentistry Department, Faculty of Dentistry, AJA University of Medical Sciences, Tehran, Iran
| | - MEHRAN ASHRAFI
- Operative Dentistry Department, Faculty of Dentistry, AJA University of Medical Sciences, Tehran, Iran
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Bergamo ETP, Yamaguchi S, Lopes ACO, Coelho PG, de Araújo-Júnior ENS, Benalcázar Jalkh EB, Zahoui A, Bonfante EA. Performance of crowns cemented on a fiber-reinforced composite framework 5-unit implant-supported prostheses: in silico and fatigue analyses. Dent Mater 2021; 37:1783-1793. [PMID: 34588130 DOI: 10.1016/j.dental.2021.09.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 09/02/2021] [Accepted: 09/13/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To characterize the biomechanical performance of fiber-reinforced composite 5-unit implant-supported fixed dental prostheses (FDPs) receiving individually milled crowns by insilico and fatigue analyses. METHODS Eighteen implant-supported five-unit fiber-reinforced composite frameworks with an individually prepared abutment design were fabricated, and ninety resin-matrix ceramic crowns were milled to fit each abutment. FDPs were subjected to step-stress accelerated-life testing with load delivered at the center of the pontic and at 2nd molar and 1st premolar until failure. The reliability of the prostheses combining all loaded data and of each loaded tooth was estimated for a mission of 50,000 cycles at 300, 600 and 900 N. Weibull parameters were calculated and plotted. Fractographic and finite element analysis were performed. RESULTS Fatigue analysis demonstrated high probability of survival at 300 N, with no significant differences when the set load was increased to 600 and 900 N. 1st and 2nd molar dataset showed high reliability at 300 N, which remained high for the higher load missions; whereas 1st premolar dataset showed a significant decrease when the reliability at 300 N was compared to higher load missions. The characteristic-strength of the combined dataset was 1252 N, with 1st molar dataset presenting higher values relative to 2nd molar and 1st premolar, both significantly different. Failure modes comprised chiefly cohesive fracture within the crown material originated from cracks at the occlusal area, matching the maximum principal strain location. SIGNIFICANCE Five-unit implant-supported FDP with crowns individually cemented in a fiber-reinforced composite framework presented a high survival probability. Crown fracture comprised the main failure mode.
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Affiliation(s)
- Edmara T P Bergamo
- Department of Prosthodontics and Periodontology, University of São Paulo - Bauru School of Dentistry, Bauru, SP, Brazil
| | - Satoshi Yamaguchi
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, 565-0871, Suita, Osaka, Japan
| | - Adolfo C O Lopes
- Department of Prosthodontics and Periodontology, University of São Paulo - Bauru School of Dentistry, Bauru, SP, Brazil
| | - Paulo G Coelho
- Department of Biomaterials, New York University College of Dentistry, New York, NY, USA; Hansjörg Wyss Department of Plastic Surgery, NYU Langone Medical Center, New York, NY, USA; Mechanical and Aerospace Engineering, NYU Tandon School of Engineering, Brooklyn, NY, USA
| | - Everardo N S de Araújo-Júnior
- Department of Prosthodontics and Periodontology, University of São Paulo - Bauru School of Dentistry, Bauru, SP, Brazil
| | - Ernesto B Benalcázar Jalkh
- Department of Prosthodontics and Periodontology, University of São Paulo - Bauru School of Dentistry, Bauru, SP, Brazil; Department of Biomaterials, New York University College of Dentistry, New York, NY, USA.
| | - Abbas Zahoui
- Department of Prosthodontics and Periodontology, University of São Paulo - Bauru School of Dentistry, Bauru, SP, Brazil
| | - Estevam A Bonfante
- Department of Prosthodontics and Periodontology, University of São Paulo - Bauru School of Dentistry, Bauru, SP, Brazil
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Baldissara P, Koci B, Monaco C, Scotti N, Breschi L, Ciocca L. Fatigue failure and success rate of lithium disilicate table-tops as a function of cement thickness. J Prosthodont Res 2021; 65:528-534. [PMID: 34108297 DOI: 10.2186/jpr.jpr_d_20_00220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE Under thin, partial coverage restoration the proper cement thickness to be clinically employed still remains an issue. The aim of this study was to determine the failure and success rates of simplified lithium disilicate occlusal veneers as a function of cement thickness. The null hypothesis was that cement thickness has no effect on the fatigue resistance. METHODS Sound human molars were severed in a plane parallel to the occlusal surface to create a flat dentin surface surrounded by enamel edges. Forty-five occlusal veneers 1.0 mm thick (IPS e.max CAD LT) were luted to the teeth with Multilink Automix resin cement, creating 3 experimental groups (n=15) with cement thicknesses of 50, 100, and 200 µm. The restorations were fatigue-cycled using a ball mill machine containing zirconia and stainless steel spheres. Twelve 60 min cycles were performed. Survival statistics were applied to "failure" and "success" events, comparing the three groups using a log-rank Mantel-Cox test and a log-rank test for trends (alpha = 0.05). RESULTS The failure and success rates were not significantly influenced by cement thickness (P = 0.137 and P = 0.872, respectively); thus, the null hypothesis was accepted. However, when log-rank test for trends was applied to failure events, the tendency to have less failures with increasing thicknesses was found statistically significant (P = 0.047). CONCLUSIONS The cement thickness within the range adopted here did not have a significant effect on the failure or success rate of lithium disilicate occlusal veneers when exposed to randomized impact stresses generating fatigue phenomena.
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Affiliation(s)
- Paolo Baldissara
- Section of Prosthodontics, Department of Biomedical and Neuromotor Science, Alma Mater Studiorum University of Bologna
| | - Brunilda Koci
- Faculty of Dental Sciences, Aldent University, Tirana
| | - Carlo Monaco
- Department of Biomedical and Neuromotor Science, Alma Mater Studiorum University of Bologna
| | - Nicola Scotti
- Department of Surgical Sciences, University of Turin
| | - Lorenzo Breschi
- Section of Prosthodontics, Department of Biomedical and Neuromotor Science, Alma Mater Studiorum University of Bologna
| | - Leonardo Ciocca
- Section of Prosthodontics, Department of Biomedical and Neuromotor Science, Alma Mater Studiorum University of Bologna
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8
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Bergamo ETP, Bastos TMC, Lopes ACO, de Araujo Júnior ENS, Coelho PG, Benalcazar Jalkh EB, Zahoui A, Bonfante EA. Physicochemical and mechanical characterization of a fiber-reinforced composite used as frameworks of implant-supported prostheses. Dent Mater 2021; 37:e443-e453. [PMID: 33865619 DOI: 10.1016/j.dental.2021.03.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 12/31/2020] [Accepted: 03/29/2021] [Indexed: 11/16/2022]
Abstract
OBJECTIVES To characterize the physicochemical and mechanical properties of a milled fiber-reinforced composite (FRC) for implant-supported fixed dental prostheses (FDPs). METHODS For FRC characterization, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction, Fourier-transformed infrared spectrometry, simultaneous thermogravimetric analysis and differential scanning calorimetry were performed. For fatigue testing, 3-unit FRC frameworks were fabricated with conventional (9 mm2 connector area) and modified designs (12 mm2 connector area and 2.5 mm-height lingual extension). A hybrid resin composite was veneered onto the frameworks. FDPs were subjected to step-stress accelerated-life fatigue testing until fracture or suspension. Use level probability Weibull curves at 300 N were plotted and the reliability for 100,000 cycles at 300, 600 and 800 N was calculated. Fractographic analysis was performed by stereomicroscope and SEM. RESULTS The FRC consisted of an epoxy resin (∼25%) matrix reinforced with inorganic particles and glass fibers (∼75%). Multi-layer continuous regular-geometry fibers were densely arranged in a parallel and bidirectional fashion in the resin matrix. Fatigue analysis demonstrated high probability of survival (99%) for FDPs at 300 N, irrespective of framework design. Conventional FDPs showed a progressive decrease in the reliability at 600 (84%) and 800 N (19%), whereas modified FDPs reliability significantly reduced only at 800 N (75%). The chief failure modes for FRC FDPs were cohesive fracture of the veneering composite on lower loads and adhesive fracture of the veneering composite at higher loads. SIGNIFICANCE Milled epoxy resin matrix reinforced with glass fibers composite resulted in high probability of survival in the implant-supported prosthesis scenario.
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Affiliation(s)
- Edmara T P Bergamo
- Department of Prosthodontics and Periodontology, University of São Paulo, Bauru School of Dentistry, 9-75, Otávio Pinheiro Brisola, 17012-901, Bauru, SP, Brazil.
| | - Tiago M C Bastos
- Department of Physics, Technological Institute of Aeronautics, 50 Marechal Eduardo Gomes, 12228-900, São José dos Campos, SP, Brazil
| | - Adolfo C O Lopes
- Department of Prosthodontics and Periodontology, University of São Paulo, Bauru School of Dentistry, 9-75, Otávio Pinheiro Brisola, 17012-901, Bauru, SP, Brazil
| | - Everardo N S de Araujo Júnior
- Department of Prosthodontics and Periodontology, University of São Paulo, Bauru School of Dentistry, 9-75, Otávio Pinheiro Brisola, 17012-901, Bauru, SP, Brazil
| | - Paulo G Coelho
- Department of Biomaterials and Biomimetics, Hansjorg Wyss Department of Plastic Surgery, Mechanical and Aerospace Engineering, New York University, 345 24th Street, 10010, New York City, NY, USA
| | - Ernesto B Benalcazar Jalkh
- Department of Prosthodontics and Periodontology, University of São Paulo, Bauru School of Dentistry, 9-75, Otávio Pinheiro Brisola, 17012-901, Bauru, SP, Brazil; Department of Biomaterials and Biomimetics, Hansjorg Wyss Department of Plastic Surgery, Mechanical and Aerospace Engineering, New York University, 345 24th Street, 10010, New York City, NY, USA
| | - Abbas Zahoui
- Department of Prosthodontics and Periodontology, University of São Paulo, Bauru School of Dentistry, 9-75, Otávio Pinheiro Brisola, 17012-901, Bauru, SP, Brazil
| | - Estevam A Bonfante
- Department of Prosthodontics and Periodontology, University of São Paulo, Bauru School of Dentistry, 9-75, Otávio Pinheiro Brisola, 17012-901, Bauru, SP, Brazil
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Ramos GF, Ramos NC, Alves LMM, Kaizer MR, Borges ALS, Campos TMB, Melo RM. Failure probability and stress distribution of milled porcelain-zirconia crowns with bioinspired/traditional design and graded interface. J Mech Behav Biomed Mater 2021; 119:104438. [PMID: 33798936 DOI: 10.1016/j.jmbbm.2021.104438] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 09/14/2020] [Accepted: 02/26/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To evaluate the failure probability and stress distribution of traditional and bioinspired porcelain-zirconia milled crowns, with and without silica infiltration (graded zirconia). METHODS Traditional crown design had a zirconia infrastructure veneered with porcelain; Bioinspired, had a porcelain infrastructure with translucent-zirconia veneer; Graded and Graded Bioinspired crowns had their zirconia layer infiltrated by silica (n = 25). The cameo surface of each crown (porcelain or zirconia) was glazed. The restoration layers were fused by a vitreous connector and the crowns were adhesively cemented to dies. The specimens were then mechanically cycled in a sliding machine using 100 N load at 4 Hz. The specimens were tested until 2 × 106 cycles, and every 0.5 × 106 cycles the crowns were evaluated under stereomicroscopy for the presence of failures. The stress distribution was inspected with Finite Element Analyses. RESULTS The predominant failure modes for the Traditional and Graded crowns were delamination and cracking, respectively. The Weibull parameters beta and eta were, respectively: Traditional 1.30 and 2.3 × 106 cycles, and Graded 1.95 and 2.3 × 106 cycles. Thus, the Traditional and Graded crowns presented greater susceptibility to failure due to fatigue, while the Bioinspired and Graded Bioinspired crowns showed no fatigue effect using 100N load, showing beta = 1 and eta of approximately 17 × 106 cycles. Also, through finite element analyses, it was verified that the Bioinspired and Graded Bioinspired crowns presented the best stress distribution on both crowns and dental structures. SIGNIFICANCE Bioinspired and Graded Bioinspired crowns had the lowest failure probability and better stress distribution and may be considered robust long lasting restorations.
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Affiliation(s)
- G F Ramos
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Institute of Science and Technology, 777 Eng. Francisco José Longo Avenue, 12245-000, São José Dos Campos, SP, Brazil.
| | - N C Ramos
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Institute of Science and Technology, 777 Eng. Francisco José Longo Avenue, 12245-000, São José Dos Campos, SP, Brazil; College of Dentistry, Sao Francisco University (USF), 218 Sao Francisco de Assis Avenue, 12916-900, Bragança Paulista, SP, Brazil.
| | - L M M Alves
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Institute of Science and Technology, 777 Eng. Francisco José Longo Avenue, 12245-000, São José Dos Campos, SP, Brazil.
| | - M R Kaizer
- College of Dentistry, Positivo University (UP), 5300 Prof. Pedro Viriato Parigot de Souza Street, 81280-330, Curitiba, PR, Brazil.
| | - A L S Borges
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Institute of Science and Technology, 777 Eng. Francisco José Longo Avenue, 12245-000, São José Dos Campos, SP, Brazil.
| | - T M B Campos
- Physics Department, Technological Institute of Aeronatics (ITA), 50 Praça Marechal Eduardo Gomes, 12228-900, São José Dos Campos, SP, Brazil.
| | - R M Melo
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Institute of Science and Technology, 777 Eng. Francisco José Longo Avenue, 12245-000, São José Dos Campos, SP, Brazil.
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Alao AR, Stoll R, Zhang Y, Yin L. Influence of CAD/CAM milling, sintering and surface treatments on the fatigue behavior of lithium disilicate glass ceramic. J Mech Behav Biomed Mater 2021; 113:104133. [PMID: 33049621 PMCID: PMC7797189 DOI: 10.1016/j.jmbbm.2020.104133] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/01/2020] [Accepted: 10/04/2020] [Indexed: 11/30/2022]
Abstract
This paper reports on the process-fatigue relation of lithium disilicate glass ceramic (LDGC) using low-cycle, high-load Hertzian indentations with a rigid indenter to simulate teeth grinding/clenching of LDGC restorations with different surface asperities obtained in CAD/CAM milling, sintering, polishing and glazing. The maximum contact stresses were evaluated as functions of the number of load cycles and surface treatments using the Hertzian model. Indentation-induced surface damage was viewed using scanning electron microscopy (SEM) to understand the relationships among microstructures, surface asperities, crack morphology and propagation. Different processes and surface treatments significantly affected the maximum contact stresses of indented LDGC surfaces (ANOVA, p < 0.05), which were all significantly reduced with the number of cycles (ANOVA, p < 0.05). Quasi-plastic deformation was dominant in single-cycle indentation of all processed and treated surfaces. In higher cycle indentations, inner cone cracks were formed on all surfaces; median and transverse cracks were formed on the roughest surfaces processed by CAD/CAM milling and sintering. Ring cracks, fretting, pulverization, micro-bridges, surface smearing and wedging, and edge chippings were also propagated on all surfaces. The process-fatigue relation provides an understanding of the mechanical functions of surface asperities produced in different processes and treatments. It indicates that the mechanically assisted growth of surface asperities with different roughness strongly affected the indentation-induced surface damage. Finally, the smoothest surfaces produced by CAD/CAM milling, polishing and sintering sustained the highest contact stresses and the least fatigue damage at higher cycles, ensuring their superior fatigue performance compared to other processed LDGC surfaces.
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Affiliation(s)
- Abdur-Rasheed Alao
- Mechanical Engineering Programme Area, Faculty of Engineering, Universiti Teknologi Brunei, Gadong, BE1410, Brunei Darussalam.
| | - Richard Stoll
- Restorative Dentistry, College of Medicine and Dentistry, James Cook University, Cairns, QLD, 4870, Australia
| | - Yu Zhang
- Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Ling Yin
- School of Mechanical Engineering, The University of Adelaide, Adelaide, SA, 5005, Australia.
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Ruggiero MM, Soares Gomes R, Pedroso Bergamo ET, Freitas MIM, Bonfante EA, Del Bel Cury AA. Resin-matrix ceramics for occlusal veneers: Effect of thickness on reliability and stress distribution. Dent Mater 2020; 37:e131-e139. [PMID: 33276957 DOI: 10.1016/j.dental.2020.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 07/31/2020] [Accepted: 11/02/2020] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To evaluate the influence of resin-matrix ceramic material and thickness on reliability and stress distribution of occlusal veneers (OV). METHODS One hundred and twenty-six OV of a mandibular first molar were milled using a CAD/CAM system and allocated according to materials (resin nanoceramic (RNC) or polymer-infiltrated ceramic network (PICN)) and thicknesses (0.5, 1.0 and 1.5 mm), totaling six groups (RNC0.5, RNC1, RNC1.5, PICN0.5, PICN1, and PICN1.5). Step-stress accelerated-life testing was performed (n = 21/group) with the load applied at the distobuccal cusp tip of the occlusal veneer until failure or suspension. The use level probability Weibull curves and reliability were calculated and plotted (90% CI). Finite element analysis evaluated the stress distribution according to maximum principal stress (σmax) on the restoration and maximum shear stress (τmax) on the cement layer. RESULTS There was no difference in the probability of survival for the estimated missions among the groups, except at 600 N in which the results were significantly lower to PICN1.5 (6%) compared to RNC1 (55%) and RNC1.5 (60%). The σmax values were higher for PICN (31.85-48.63 MPa) than RNC (30.78-33.09 MPa) in the same thicknesses. In addition, 0.5 mm groups concentrated more stress in the restoration (33.09-48.63 MPa) than 1.0 mm (31.11-35.36 MPa) and 1.5 mm (30.78-31.85 MPa) groups in the same material. SIGNIFICANCE Both resin-matrix ceramic materials seem up-and-coming restorative systems for occlusal veneers irrespective of the thicknesses as a consequence of the high reliability.
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Affiliation(s)
- Mirelle Maria Ruggiero
- Department of Prosthodontics and Periodontology, University of Campinas - Piracicaba Dental School, Limeira Avenue, 901, Piracicaba, SP, 13414-903, Brazil
| | - Rafael Soares Gomes
- Department of Prosthodontics and Periodontology, University of Campinas - Piracicaba Dental School, Limeira Avenue, 901, Piracicaba, SP, 13414-903, Brazil
| | - Edmara Tatiely Pedroso Bergamo
- Department of Prosthodontics and Periodontology, University of São Paulo - Bauru School of Dentistry, Dr. Octávio Pinheiro Brisolla Avenue, 9-75, Bauru, SP, 17012-901, Brazil
| | - Mariana Itaborai Moreira Freitas
- Department of Prosthodontics and Periodontology, University of Campinas - Piracicaba Dental School, Limeira Avenue, 901, Piracicaba, SP, 13414-903, Brazil
| | - Estevam Augusto Bonfante
- Department of Prosthodontics and Periodontology, University of São Paulo - Bauru School of Dentistry, Dr. Octávio Pinheiro Brisolla Avenue, 9-75, Bauru, SP, 17012-901, Brazil
| | - Altair Antoninha Del Bel Cury
- Department of Prosthodontics and Periodontology, University of Campinas - Piracicaba Dental School, Limeira Avenue, 901, Piracicaba, SP, 13414-903, Brazil.
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Impact of Coping Veneering Techniques on the Survival of Implant-Supported Zirconia-Based-Crowns Cemented to Hybrid-Abutments: An-In-Vitro Study. Bioengineering (Basel) 2020; 7:bioengineering7040117. [PMID: 32992792 PMCID: PMC7712862 DOI: 10.3390/bioengineering7040117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/14/2020] [Accepted: 09/20/2020] [Indexed: 11/17/2022] Open
Abstract
The objective of this study is to investigate the influence of veneering technique (hand-layering vs. milling) on the fracture resistance of bi-layer implant-supported zirconia-based hybrid-abutment crowns. Mandibular molar copings were anatomically designed and milled. Copings were then veneered by hand-layering (HL) (n = 20) and milling using the Cad-On technique (LD) (n = 20). Crowns were cemented to zirconia hybrid-abutments. Ten samples of each group acted as a control while the remaining ten samples were subjected to fatigue in a chewing simulator. Crowns were loaded between 50 and 100 N for 1.2 million cycles under simultaneous temperature fluctuation between 5 and 55 °C. Crowns were then subjected to static load a to fracture test. Data were statistically analysed using the one-way ANOVA. Randomly selected crowns from each group were observed under scanning electron microscopy to view fractured surfaces. Study results indicate that during fatigue, LD crowns had a 100% survival rate; while HL crowns had a 50% failure rate. Fracture resistance of LD crowns was statistically significantly higher than that of HL crowns at the baseline and after fatigue (p ≤ 0.05). However, fatigue did not cause a statistically significant reduction in fracture resistance in both LD and HL groups (p > 0.05). Copings fractured in the LD crowns only and the fracture path was different in both LD and HL groups. According to the results, it was concluded that milled veneer implant-supported hybrid-abutment crowns exhibit significantly higher fracture resistance, and better withstand clinical masticatory loads in the posterior region compared to the hand-layered technique. Also, fatigue application and artificial aging caused no significant strength reduction in both techniques. Clinical significance: Different veneering techniques and materials (hand-layering or milling) act differently to clinical forces and environment and may be prone to early chipping during service. Therefore, practitioners are urged to consider the appropriate veneering protocol for posterior implant-supported hybrid-abutment restorations.
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13
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Mallya J, DuVall N, Brewster J, Roberts H. Endodontic Access Effect on Full Contour Zirconia and Lithium Disilicate Failure Resistance. Oper Dent 2020; 45:276-285. [DOI: 10.2341/18-231-l] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Objectives:
To evaluate the effect of endodontic access on the failure load resistance of both adhesively and conventionally luted, full-contour monolithic yttria-stabilized zirconium dioxide (Y-TZP) and adhesively luted lithium disilicate (LD) crowns cemented on prepared teeth.
Methods and Materials:
Seventy-two human maxillary molars were prepared per respective guidelines for all-ceramic crowns with one group (n=24) restored with LD and the other (n=48) receiving Y-TZP crowns. Preparations were scanned using computer-aided design/computer-aided milling (CAD/CAM) technology, and milled crowns were sintered following manufacturer recommendations. All LD crowns and half (n=24) of the Y-TZP crowns were adhesively cemented, while the remaining Y-TZP specimens were luted using a conventional glass ionomer cement (GIC). One LD group, one Y-TZP adhesive group, and one GIC-luted group (all n=12) then received endodontic access preparations by a board-certified endodontist: the pulp chambers were restored with a dual-cure, two-step, self-etch adhesive and a dual-cure resin composite core material. The access preparations were restored using a nano-hybrid resin composite after appropriate ceramic margin surface preparation. After 24 hours, all specimens were loaded axially until failure; mean failure loads were analyzed using Mann-Whitney U test (α=0.05)
Results:
Endodontic access did not significantly reduce the failure load of adhesively luted LD or Y-TZP crowns, but Y-TZP crowns with GIC cementation demonstrated significantly less failure load.
Conclusions:
These initial findings suggest that endodontic access preparation may not significantly affect failure load resistance of adhesively luted Y-TZP and LD crowns. Definitive recommendations cannot be proposed until fatigue testing and coronal seal evaluations have been accomplished.
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Affiliation(s)
- J Mallya
- John Mallya, DMD, MS, 47th Medical Group, Laughlin AFB, TX, USA
| | - N DuVall
- Nicholas DuVall, DDS, MS, 96th Dental Squadron, Eglin AFB, FL USA
| | - J Brewster
- John Brewster, DDS, MS, USAF Postgraduate Dental School, Keesler AFB, MS, USA
| | - H Roberts
- Howard Roberts, DMD, MS, Division of Restorative Dentistry, University of Kentucky College of Dentistry, Lexington, KY, USA
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14
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Ayode Otitoju T, Ugochukwu Okoye P, Chen G, Li Y, Onyeka Okoye M, Li S. Advanced ceramic components: Materials, fabrication, and applications. J IND ENG CHEM 2020. [DOI: 10.1016/j.jiec.2020.02.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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15
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Goiato MC, Andreotti AM, dos Santos DM, Nobrega AS, de Caxias FP, Bannwart LC. Influence of length, diameter and position of the implant in its fracture incidence: A Systematic Review. J Dent Res Dent Clin Dent Prospects 2019; 13:109-116. [PMID: 31592306 PMCID: PMC6773918 DOI: 10.15171/joddd.2019.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 07/02/2019] [Indexed: 11/29/2022] Open
Abstract
Background. Implant fractures can cause difficult problems for patients and dentists. This systematic review aimed to determine the influence of some implant parameters on the occurrence of their fracture and to determine the incidence of fractures reported in recent years.
Methods. A search was conducted in Pubmed database, from which 12 studies published in the last 12 years were selected.
Results. This review reported a 2% incidence of implant fracture. Most implants had been in function between 3 and 4 years until fracture. The studies did not provide necessary information to establish a relationship between the different parameters of implants and the incidence of fractures.
Conclusion. Thus, the indication of type, diameter and length of an implant and the bone quality in the region receiving it should be studied and accurately examined for each individual case in order to avoid future failures.
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Affiliation(s)
- Marcelo Coelho Goiato
- Professor, Department of Dental Materials and Prosthodontics; Araçatuba Dental School, São Paulo State University Júlio de Mesquita Filho, UNESP, Araçatuba, Brazil
| | - Agda Marobo Andreotti
- PhD Student; Department of Dental Materials and Prosthodontics; Araçatuba Dental School, São Paulo State University Júlio de Mesquita Filho, UNESP, Araçatuba, Brazi
| | | | - Adhara Smith Nobrega
- PhD Student; Department of Dental Materials and Prosthodontics; Araçatuba Dental School, São Paulo State University Júlio de Mesquita Filho, UNESP, Araçatuba, Brazi
| | - Fernanda Pereira de Caxias
- PhD Student; Department of Dental Materials and Prosthodontics; Araçatuba Dental School, São Paulo State University Júlio de Mesquita Filho, UNESP, Araçatuba, Brazi
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16
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Elasticity, plasticity and analytical machinability prediction of lithium metasilicate/disilicate glass ceramics. J Mech Behav Biomed Mater 2019; 96:9-19. [DOI: 10.1016/j.jmbbm.2019.04.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 04/12/2019] [Accepted: 04/16/2019] [Indexed: 11/16/2022]
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17
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Ferruzzi F, Ferrairo BM, Piras FF, Borges AFS, Rubo JH. Fatigue survival and damage modes of lithium disilicate and resin nanoceramic crowns. J Appl Oral Sci 2019; 27:e20180297. [PMID: 31166548 PMCID: PMC6534377 DOI: 10.1590/1678-7757-2018-0297] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 11/28/2018] [Indexed: 11/22/2022] Open
Abstract
Polymer-based composite materials have been proposed as an alternative for single unit restorations, due to their resilient and shock absorbing behavior, in contrast to the brittleness of ceramic materials that could result in failure by fracture.
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Affiliation(s)
| | - Brunna M Ferrairo
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departamento de Prótese, Bauru, São Paulo, Brasil
| | - Fernanda F Piras
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departamento de Prótese, Bauru, São Paulo, Brasil
| | - Ana Flávia Sanches Borges
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departamento de Dentística, Endodontia e Materiais Dentários, Bauru, São Paulo, Brasil
| | - José Henrique Rubo
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departamento de Prótese, Bauru, São Paulo, Brasil
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18
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Baldissara P, Monaco C, Onofri E, Fonseca RG, Ciocca L. Fatigue resistance of monolithic lithium disilicate occlusal veneers: a pilot study. Odontology 2019; 107:482-490. [PMID: 30840218 DOI: 10.1007/s10266-019-00417-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 02/20/2019] [Indexed: 10/27/2022]
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19
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Kim HW, Choi BH, Bae EJ, Lim JY. Comparison of stress distribution in dental crown with different cusp angles: 3D finite element analysis. Comput Methods Biomech Biomed Engin 2019; 22:251-258. [DOI: 10.1080/10255842.2018.1549659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Han-Wool Kim
- Department of Mechanical Engineering, Dongguk University, Seoul, South Korea
| | - Byung-Ho Choi
- Department of Dentistry Wonju College of Medicine, Yonsei University, Wonju, South Korea
| | - Eun-Jeong Bae
- Department of Mechanical, Robotics, and Energy Engineering, Dongguk University, Seoul, South Korea
| | - Joong-Yeon Lim
- Department of Mechanical, Robotics, and Energy Engineering, Dongguk University, Seoul, South Korea
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20
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Fatigue behavior and crack initiation of CAD/CAM resin composite molar crowns. Dent Mater 2018; 34:1578-1584. [DOI: 10.1016/j.dental.2018.07.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 06/12/2018] [Accepted: 07/09/2018] [Indexed: 11/21/2022]
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21
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Tsuyuki Y, Sato T, Nomoto S, Yotsuya M, Koshihara T, Takemoto S, Yoshinari M. Effect of occlusal groove on abutment, crown thickness, and cement-type on fracture load of monolithic zirconia crowns. Dent Mater J 2018; 37:843-850. [PMID: 29962415 DOI: 10.4012/dmj.2017-350] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The aim of this study was to investigate the effects of occlusal form of abutment, occlusal thickness of monolithic zirconia crowns (MZC), and cement type on the fracture load of MZC. Abutments were prepared with 2 types of occlusal forms: groove-type and flat-type. These were designed so that thickness at the central fissure region of MZC was 0.3, 0.5, or 0.7 mm. Glass ionomer cement and resin cement were used to lute MZC to their corresponding abutment. Fracture load was determined using a universal testing machine. As a result, groove-type abutment had lower fracture load compared to flat-type abutment; however, the decline in strength was smaller when resin cement was used. Additionally, specimens with larger occlusal thickness had greater fracture load regardless of groove or cement-type. The fracture of MZC occurred on the central fissure region of MZC except for 0.7 mm groove-type MZC luted with resin cement.
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Affiliation(s)
- Yu Tsuyuki
- Department of Fixed Prosthodontics, Tokyo Dental College.,Oral Health Center, Tokyo Dental College
| | - Toru Sato
- Department of Fixed Prosthodontics, Tokyo Dental College
| | | | - Mamoru Yotsuya
- Department of Fixed Prosthodontics, Tokyo Dental College
| | | | - Shinji Takemoto
- Oral Health Center, Tokyo Dental College.,Department of Dental Materials Science, Tokyo Dental College.,Deparment of Biomedical Engineering, Iwate Medical University
| | - Masao Yoshinari
- Department of Dental Materials Science, Tokyo Dental College
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22
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Hydrofluoric acid concentrations: Effect on the cyclic load-to-failure of machined lithium disilicate restorations. Dent Mater 2018; 34:e255-e263. [DOI: 10.1016/j.dental.2018.06.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 06/08/2018] [Accepted: 06/25/2018] [Indexed: 01/23/2023]
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23
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Gerogianni P, Lien W, Bompolaki D, Verrett R, Haney S, Mattie P, Johnson R. Fracture Resistance of Pressed and Milled Lithium Disilicate Anterior Complete Coverage Restorations Following Endodontic Access Preparation. J Prosthodont 2018; 28:163-170. [PMID: 29682833 DOI: 10.1111/jopr.12798] [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] [Accepted: 02/17/2018] [Indexed: 11/26/2022] Open
Abstract
PURPOSE This in vitro study evaluated the fracture resistance and clinical prognosis of anterior lithium disilicate crowns (e.max Press and e.max CAD), following endodontic access and repair. The research design simulates intraoral loading conditions to produce clinically applicable results. MATERIALS AND METHODS Monolithic anterior crowns, based on #8 anatomy, were fabricated from e.max Press ingots and e.max CAD blocks and adhesively bonded on identical dies milled out of a dentin analog material (NEMA G10). Specimens were divided into 4 groups: intact pressed, repaired pressed, intact milled, and repaired milled (n = 15/group). Repaired pressed and repaired milled were prepared with a standardized endodontic access and repaired using a porcelain repair system and composite resin. All crowns were cyclically loaded under simulated oral conditions and then loaded to failure in water, using a universal testing machine. Data were interpreted using ANOVA/Tukey post-hoc test (α = 0.05). RESULTS Mean loads to failure ranged from 758.9 to 931.4 N for the 4 groups, indicating that both fabrication techniques, pressed and milled, yielded restorations that could reasonably withstand maximum masticatory forces. The pressed groups (923.7 N) exhibited significantly higher fracture resistance than the milled groups (797.5 N), p = 0.0002. When milled and pressed groups were categorized into intact and repaired subgroups, no difference was found in fracture resistance between the subgroups. Differences were noted in the modes of fracture, where the milled groups (intact and repaired) exhibited higher frequency of catastrophic fractures than the pressed groups. CONCLUSIONS Endodontic access preparation does not appear to affect fracture resistance of an anterior lithium disilicate restoration, suggesting that replacement may not be necessary. Fabrication technique had a significant effect on fracture resistance and fracture mode of lithium disilicate restorations. The pressed fabrication technique resulted in significantly greater crown strength and fracture resistance than the milled technique.
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Affiliation(s)
- Petrina Gerogianni
- Department of Comprehensive Dentistry, Graduate School of Biomedical Sciences, University of Texas Health Science Center at San Antonio, TX
| | - Wen Lien
- US Air Force Dental Evaluation & Consultation Service - Dental Materials Research San Antonio, TX
| | - Despoina Bompolaki
- Department of Restorative Dentistry, Oregon Health and Science University School of Dentistry, Portland, OR
| | - Ronald Verrett
- Department of Comprehensive Dentistry, Graduate School of Biomedical Sciences, University of Texas Health Science Center at San Antonio, TX
| | - Stephan Haney
- Department of Comprehensive Dentistry, Graduate School of Biomedical Sciences, University of Texas Health Science Center at San Antonio, TX
| | - Patrick Mattie
- Department of Comprehensive Dentistry, Graduate School of Biomedical Sciences, University of Texas Health Science Center at San Antonio, TX
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24
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Nasrin S, Katsube N, Seghi RR, Rokhlin SI. Approximate relative fatigue life estimation methods for thin-walled monolithic ceramic crowns. Dent Mater 2018; 34:726-736. [PMID: 29402538 DOI: 10.1016/j.dental.2018.01.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 12/27/2017] [Accepted: 01/16/2018] [Indexed: 11/27/2022]
Abstract
OBJECTIVES The objective is to establish an approximate relative fatigue life estimation method under simulated mastication load for thin-walled monolithic restorations. METHODS Experimentally measured fatigue parameters of fluormica, leucite, lithium disilicate and yttrium-stabilized zirconia in the existing literature were expressed in terms of the maximum cyclic stress and stress corresponding to initial crack size prior to N number of loading cycles to assess their differences. Assuming that failures mostly originate from high stress region, an approximate restoration life method was explored by ignoring the multi-axial nature of stress state. Experiments utilizing a simple trilayer restoration model with ceramic LD were performed to test the model validity. RESULTS Ceramic fatigue was found to be similar for clinically relevant loading range and mastication frequency, resulting in the development of an approximate fatigue equation that is universally applicable to a wide range of dental ceramic materials. The equation was incorporated into the approximate restoration life estimation, leading to a simple expression in terms of fast fracture parameters, high stress area ΔA, the high stress averaged over ΔA and N. The developed method was preliminarily verified by the experiments. The impact of fast fracture parameters on the restoration life was separated from other factors, and the importance of surface preparation was manifested in the simplified equation. Both the maximum stress and the area of high stress region were also shown to play critical roles. SIGNIFICANCE While nothing can replace actual clinical studies, this method could provide a reasonable preliminary estimation of relative restoration life.
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Affiliation(s)
- Sadia Nasrin
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, USA
| | - Noriko Katsube
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, USA
| | - Robert R Seghi
- College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Stanislav I Rokhlin
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, USA
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25
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Ramos-Tonello CM, Trevizo BF, Rodrigues RF, Magalhães APR, Furuse AY, Lisboa-Filho PN, Tabata AS, Borges AFS. Pre-sintered Y-TZP sandblasting: effect on surface roughness, phase transformation, and Y-TZP/veneer bond strength. J Appl Oral Sci 2017; 25:666-673. [PMID: 29211288 PMCID: PMC5701537 DOI: 10.1590/1678-7757-2017-0131] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 06/27/2017] [Indexed: 11/22/2022] Open
Abstract
Sandblasting is a common method to try to improve the Y-TZP/veneer bond strength of dental prostheses, however, it may put stress on zirconia surfaces and could accelerate the t→m phase transformation. Y-TZP sandblasting before sintering could be an alternative to improve surface roughness and bonding strength of veneering ceramic.
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Affiliation(s)
| | | | - Raphaela Farias Rodrigues
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departamento de Dentística, Endodontia e Materiais Dentários, Bauru, SP, Brasil
| | - Ana Paula Rodrigues Magalhães
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departamento de Dentística, Endodontia e Materiais Dentários, Bauru, SP, Brasil
| | - Adilson Yoshio Furuse
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departamento de Dentística, Endodontia e Materiais Dentários, Bauru, SP, Brasil
| | | | | | - Ana Flávia Sanches Borges
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departamento de Dentística, Endodontia e Materiais Dentários, Bauru, SP, Brasil
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26
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Fleming GJ, Cao X, Romanyk DL, Addison O. Favorable residual stress induction by resin-cementation on dental porcelain. Dent Mater 2017; 33:1258-1265. [DOI: 10.1016/j.dental.2017.07.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/19/2017] [Accepted: 07/24/2017] [Indexed: 10/19/2022]
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Compressive Resistances and Failure Modes of Abutments With Different Transgingival Heights and Types on Internal Conical Connected Implants. IMPLANT DENT 2017; 26:682-689. [PMID: 28945668 DOI: 10.1097/id.0000000000000658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE This study aimed to research the effect of different transgingival heights (THs) and types of abutments on performances including the compressive resistances and fracture modes of abutments on internal conical connected implants. MATERIALS AND METHODS Three groups were established: a 1-piece zirconia abutment group (group A), a 2-piece zirconia abutment group (group B), and a 1-piece titanium abutment group (group C). Three THs (2, 3.5, and 5 mm, n = 6) were set as the subgroups of each group. All groups were subjected to a compressive resistance test at a 30 degree angle. The main failure modes were analyzed using scanning electron microscopy and a stereomicroscope. RESULTS The compressive resistances of the abutments on the internal conical connected implants were significantly related to the TH (P = 0.004), the type of abutment (P < 0.0001), and the combined effect (P < 0.0001). All of the subgroups in group C exhibited the greatest compressive loads at the same TH. Different types of abutments had different failure modes. CONCLUSIONS Both the TH and the type of abutments influenced compressive resistances of the implant-abutment complexes.
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28
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Archibald JJ, Santos GC, Moraes Coelho Santos MJ. Retrospective clinical evaluation of ceramic onlays placed by dental students. J Prosthet Dent 2017; 119:743-748.e1. [PMID: 28927922 DOI: 10.1016/j.prosdent.2017.07.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 07/11/2017] [Accepted: 07/12/2017] [Indexed: 11/18/2022]
Abstract
STATEMENT OF PROBLEM Indirect restorations with partial or complete occlusal surface coverage have been recommended to restore teeth with weakened walls in order to prevent cusp fracture. The success of these restorations when performed by dental students is unknown. PURPOSE The purpose of this retrospective study was to evaluate the clinical performance of adhesively bonded ceramic onlay restorations placed by third- and fourth-year dental students. MATERIAL AND METHODS Sixty-five ceramic onlays were placed in patients between 2009 and 2015. The onlays were laboratory or chairside fabricated with a computer-aided design and computer-aided manufacturing (CAD-CAM) system, using either IPS e.max Press or IPS e.max CAD. An adhesive technique and luting composite resin agent were used to cement the restorations. Thirty-seven onlays were evaluated clinically using the modified United States Public Health Service (USPHS) criteria. Data were statistically analyzed using the Cox proportional hazards model to compare tooth type and failures and the Fisher exact and McNemar tests to compare the USPHS criteria for significant differences (α=.05). Survival probability was calculated using the Kaplan-Meier algorithm. RESULTS Five onlays were considered to be failures and needed replacement. According to the Kaplan-Meier analysis, the estimated survival rate was 96.3% after 2 years and 91.5% at 4 years. All 5 of the failures occurred on molars (13.5%) and none on premolars (P=.025). A statistically significant difference was found for marginal discoloration between onlays placed within 0 to 3 years and 3 to 6 years (P<.05) but no differences between any other criteria. CONCLUSIONS Ceramic onlays placed by dental students demonstrated acceptable long-term clinical performance.
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Affiliation(s)
- Jennifer J Archibald
- Predoctoral student, Schulich Medicine and Dentistry, Western University, London, Ont, Canada
| | - Gildo Coelho Santos
- Associate Professor, Department of Restorative Dentistry, Schulich Medicine and Dentistry, Western University, London, Ont, Canada
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Rues S, Schwindling FS, Meyer A, Rammelsberg P, Schmitter M. Fracture resistance of zirconia-based all-ceramic crowns after bur adjustment. Eur J Oral Sci 2017; 125:310-313. [DOI: 10.1111/eos.12353] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Stefan Rues
- Department of Prosthetic Dentistry; University Hospital Heidelberg; Heidelberg Germany
| | - Franz S. Schwindling
- Department of Prosthetic Dentistry; University Hospital Heidelberg; Heidelberg Germany
| | - Andre Meyer
- Department of Prosthetic Dentistry; University Hospital Heidelberg; Heidelberg Germany
| | - Peter Rammelsberg
- Department of Prosthetic Dentistry; University Hospital Heidelberg; Heidelberg Germany
| | - Marc Schmitter
- Department of Prosthetic Dentistry; University Hospital Würzburg; Würzburg Germany
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Nasrin S, Katsube N, Seghi R, Rokhlin S. Survival Predictions of Ceramic Crowns Using Statistical Fracture Mechanics. J Dent Res 2017; 96:509-515. [PMID: 28107637 PMCID: PMC5453496 DOI: 10.1177/0022034516688444] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This work establishes a survival probability methodology for interface-initiated fatigue failures of monolithic ceramic crowns under simulated masticatory loading. A complete 3-dimensional (3D) finite element analysis model of a minimally reduced molar crown was developed using commercially available hardware and software. Estimates of material surface flaw distributions and fatigue parameters for 3 reinforced glass-ceramics (fluormica [FM], leucite [LR], and lithium disilicate [LD]) and a dense sintered yttrium-stabilized zirconia (YZ) were obtained from the literature and incorporated into the model. Utilizing the proposed fracture mechanics-based model, crown survival probability as a function of loading cycles was obtained from simulations performed on the 4 ceramic materials utilizing identical crown geometries and loading conditions. The weaker ceramic materials (FM and LR) resulted in lower survival rates than the more recently developed higher-strength ceramic materials (LD and YZ). The simulated 10-y survival rate of crowns fabricated from YZ was only slightly better than those fabricated from LD. In addition, 2 of the model crown systems (FM and LD) were expanded to determine regional-dependent failure probabilities. This analysis predicted that the LD-based crowns were more likely to fail from fractures initiating from margin areas, whereas the FM-based crowns showed a slightly higher probability of failure from fractures initiating from the occlusal table below the contact areas. These 2 predicted fracture initiation locations have some agreement with reported fractographic analyses of failed crowns. In this model, we considered the maximum tensile stress tangential to the interfacial surface, as opposed to the more universally reported maximum principal stress, because it more directly impacts crack propagation. While the accuracy of these predictions needs to be experimentally verified, the model can provide a fundamental understanding of the importance that pre-existing flaws at the intaglio surface have on fatigue failures.
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Affiliation(s)
- S. Nasrin
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, USA
| | - N. Katsube
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, USA
| | - R.R. Seghi
- College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - S.I. Rokhlin
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, USA
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Gorman CM, Ray NJ, Burke FM. The effect of endodontic access on all-ceramic crowns: A systematic review of in vitro studies. J Dent 2016; 53:22-9. [PMID: 27542693 DOI: 10.1016/j.jdent.2016.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 07/20/2016] [Accepted: 08/14/2016] [Indexed: 10/21/2022] Open
Abstract
OBJECTIVES The aim of this systematic review was to identify from in vitro studies the effect of endodontic access on the fracture resistance and damage around the access cavity of all-ceramic crowns. DATA The articles identified were screened by two reviewers according to inclusion and exclusion criteria. The reference lists of articles advanced to second round screening were hand searched to identify additional potential articles. The risk of bias for the articles was independently performed by two reviewers. SOURCES An electronic search was conducted on PubMed/Medline, Web of Science, Scopus and Embase databases with no limitations. STUDY SELECTION 383 articles were identified, of which, eight met the inclusion criteria and formed the basis of this systematic review. Factors investigated in the selected articles included the, presence of microcracks at the access cavity, repair protocol, ceramic type, crown fabrication method, luting agent and grit size of the diamond bur. The risk of bias was deemed to be high for three, medium for two and low for three of the reviewed studies. The high level of heterogeneity across the studies precluded meta-analyses. CONCLUSION Based on the currently available scientific evidence, a 'best practice' protocol with regard to improving the fracture resistance of endodontically accessed and repaired all-ceramic crowns cannot be conclusively identified. However, some key factors which potentially impact on the fracture resistance of endodontically accessed and repaired all-ceramic crowns have been isolated. Cautious clinical interpretation of these factors is concluded for the maintenance of the crown as a permanent restoration. CLINICAL SIGNIFICANCE Key factors which impact on the fracture resistance of endodontically accessed and repaired all-ceramic crowns have been isolated from in vitro studies. Cautious clinical interpretation of these factors is advised for the maintenance of the crown as a permanent restoration.
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Affiliation(s)
| | - Noel J Ray
- University Dental School & Hospital, University College Cork, Ireland.
| | - Francis M Burke
- University Dental School & Hospital, University College Cork, Ireland.
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Basílio MDA, Cardoso KV, Antonio SG, Rizkalla AS, Santos Junior GC, Arioli Filho JN. Effects of artificial aging conditions on yttria-stabilized zirconia implant abutments. J Prosthet Dent 2016; 116:277-85. [DOI: 10.1016/j.prosdent.2016.01.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Revised: 01/12/2016] [Accepted: 01/12/2016] [Indexed: 11/16/2022]
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Sulaiman TA, Abdulmajeed AA, Donovan TE, Cooper LF, Walter R. Fracture rate of monolithic zirconia restorations up to 5 years: A dental laboratory survey. J Prosthet Dent 2016; 116:436-9. [PMID: 27178771 DOI: 10.1016/j.prosdent.2016.01.033] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 01/19/2016] [Accepted: 01/26/2016] [Indexed: 12/21/2022]
Abstract
STATEMENT OF PROBLEM The demand for ceramic restorations has increased over the past years because of their esthetic properties and the high cost of noble metals. However, the lack of long-term clinical studies and the difficulty of interpreting in vitro studies have placed the durability of ceramic restorations in doubt. PURPOSE The purpose of this study was to determine the failure rate of monolithic zirconia restorations due to fracture up to 5 years of clinical performance. MATERIAL AND METHODS Data were collected over 5 years from 2 commercial dental laboratories. Restorations that were returned to the laboratory for remake because of catastrophic failure (fracture) were identified and included. Restorations were categorized as anterior or posterior. Each category was further divided into complete-coverage single crowns (SCs) and multiple-unit fixed dental prostheses (FDPs). Fracture rates were compared and analyzed using a chi-square test (α=.05). RESULTS A total of 39827 restoration records were reviewed and included 3731 anterior restorations (1952 SC; 1799 FDP) and 36096 posterior restorations (29808 SC; 6288 FDP). The overall fracture rate of up to 5 years for all restorations (anterior and posterior) was 1.09%. Fracture rates were 2.06% for all anterior restorations and 0.99% for all posterior restorations. Fracture rates were 0.97% for anterior SCs and 0.69% for posterior SCs, and the combined fracture rate (anterior and posterior) was 0.71%. For FDPs, 3.26% restorations fractured anteriorly and 2.42% fractured posteriorly, and the combined fracture rate (anterior and posterior) was 2.60%. CONCLUSION Within the relative short-term evaluation of 5 years, restorations fabricated from monolithic zirconia material displayed relatively low fracture rates. Anterior restorations fractured at a slightly higher rate than posterior restorations, and FDPs fractured at a rate double that of SCs.
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Affiliation(s)
- Taiseer A Sulaiman
- Assistant Professor, Department of Operative Dentistry, University of North Carolina School of Dentistry, Chapel Hill, NC.
| | - Aous A Abdulmajeed
- Assistant Professor, Department of Prosthetic Dentistry, University of Turku Institute of Dentistry, Turku, Finland, and Visiting Scholar, Department of Prosthodontics, University of North Carolina School of Dentistry, Chapel Hill, NC
| | - Terence E Donovan
- Professor and Section Head, Biomaterials Sciences, Department of Operative Dentistry, University of North Carolina School of Dentistry, Chapel Hill, NC
| | - Lyndon F Cooper
- Stallings Distinguished Professor, Graduate Program in Prosthodontics, University of North Carolina School of Dentistry, Chapel Hill, NC
| | - Ricardo Walter
- Clinical Associate Professor, Department of Operative Dentistry, University of North Carolina School of Dentistry, Chapel Hill, NC
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Abstract
The degree of interplay among variables in dental implant treatment presents a challenge to randomized clinical trials attempting to answer questions in a timely, unbiased, and economically feasible fashion. Further adding complexity to the different scenarios is the varied implant designs and related bone response, area of implantation, implant bulk material, restoration, abutments and related screws, fixation mode (screwed, fixed, or a combination), and horizontal implant-abutment matching geometry. This article critically appraises the most common mechanical testing methods used to characterize the implant-prostheses complex. It attempts to provide insight into the process of construction of an informed database of clinically relevant questions regarding preclinical evaluation of implant biomechanics and failure mechanisms. The use of single load to failure, fatigue life, fatigue limit, and step-stress accelerated life testing is discussed with emphasis on their deliverables, weaknesses, and strengths. Fractographic analysis and challenges in the correlation between laboratory- and in-service-produced failures of dental ceramics, resin composites, and titanium are introduced. In addition, examples are presented of mechanical characterization studies used in our laboratory to assess some implant-supported rehabilitation variables.
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Pharr SW, Teixeira EC, Verrett R, Piascik JR. Influence of Veneering Fabrication Techniques and Gas-Phase Fluorination on Bond Strength between Zirconia and Veneering Ceramics. J Prosthodont 2016; 25:478-84. [PMID: 26849102 DOI: 10.1111/jopr.12451] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2015] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Porcelain chipping has been one of the main problems of porcelain-fused-to-zirconia restorations. This study evaluates the bond strengths of layered, pressed, and adhesively bonded porcelain to yttria-stabilized zirconia substrates that have undergone traditional preparation or gas-phase fluorination. MATERIALS AND METHODS A three-point bending test was used to evaluate the bond strength of the porcelain and zirconia interface. Sixty-six specimens were prepared (n = 11) following ISO 9693 and loaded until failure using an Instron testing machine. One-half of the zirconia substrates received gas phase fluorination treatment before veneering application. Three porcelain veneering methods were evaluated: layered, pressed, and adhesively bonded porcelain. Bond strength results were interpreted using a two-way ANOVA and a Bonferroni multiple comparisons test. Statistical significance was set at α = 0.05. RESULTS ANOVA revealed a statistically significant effect of the veneering fabrication methods. No main effect was observed regarding the surface treatment to the zirconia. There was a significant effect related to the veneering method used to apply porcelain to zirconia. For untreated zirconia, layered porcelain had a significantly higher flexural strength compared to pressed or bonded, while pressed and bonded porcelains were not significantly different from one another. For zirconia specimens receiving fluorination treatment, both layered and pressed porcelains had significantly higher bond strengths than adhesively bonded porcelain. In addition, fluorinated pressed porcelain was not statistically different from the control layered or fluorinated layered porcelain. CONCLUSION The choice of veneering fabrication technique was critical when evaluating the zirconia to porcelain interfacial bond strength. Bonded porcelain to zirconia had a lower flexural strength than layered or pressed porcelain, regardless of zirconia surface treatment. In addition, fluorination had an effect on the bond strength of pressed porcelain.
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Affiliation(s)
| | - Erica C Teixeira
- Department of Operative Dentistry, University of Iowa, Iowa City, IA
| | - Ronald Verrett
- Department of Comprehensive Dentistry, University of Texas Health Science Center, San Antonio, TX
| | - Jeffrey R Piascik
- RTI International, Center for Materials and Electronic Technologies, Durham, NC
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Madfa AA, Yue XG. Dental prostheses mimic the natural enamel behavior under functional loading: A review article. JAPANESE DENTAL SCIENCE REVIEW 2016; 52:2-13. [PMID: 28408950 PMCID: PMC5382785 DOI: 10.1016/j.jdsr.2015.07.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 05/18/2015] [Accepted: 07/23/2015] [Indexed: 11/30/2022] Open
Abstract
Alumina- and zirconia-based ceramic dental restorations are designed to repair functionality as well as esthetics of the failed teeth. However, these materials exhibited several performance deficiencies such as fracture, poor esthetic properties of ceramic cores (particularly zirconia cores), and difficulty in accomplishing a strong ceramic–resin-based cement bond. Therefore, improving the mechanical properties of these ceramic materials is of great interest in a wide range of disciplines. Consequently, spatial gradients in surface composition and structure can improve the mechanical integrity of ceramic dental restorations. Thus, this article reviews the current status of the functionally graded dental prostheses inspired by the dentino-enamel junction (DEJ) structures and the linear gradation in Young's modulus of the DEJ, as a new material design approach, to improve the performance compared to traditional dental prostheses. This is a remarkable example of nature's ability to engineer functionally graded dental prostheses. The current article opens a new avenue for recent researches aimed at the further development of new ceramic dental restorations for improving their clinical durability.
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Affiliation(s)
- Ahmed A. Madfa
- Department of Conservative Dentistry, Faculty of Dentistry, University of Thamar, Yemen
- Corresponding author at: Department of Conservative Dentistry, Faculty of Dentistry, University of Thamar, Dhamar, Yemen. Tel.: +967 6503255.
| | - Xiao-Guang Yue
- Department of Safety Science and Engineering, Wuhan University of Technology, China
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Song XF, Ren HT, Yin L. Machinability of lithium disilicate glass ceramic in in vitro dental diamond bur adjusting process. J Mech Behav Biomed Mater 2016; 53:78-92. [DOI: 10.1016/j.jmbbm.2015.08.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 07/30/2015] [Accepted: 08/04/2015] [Indexed: 12/13/2022]
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Ramos GF, Monteiro EBC, Bottino M, Zhang Y, de Melo RM. Failure Probability of Three Designs of Zirconia Crowns. INT J PERIODONT REST 2015; 35:843-9. [PMID: 26509988 PMCID: PMC4671273 DOI: 10.11607/prd.2448] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This study used a two-parameter Weibull analysis for evaluation of the lifespan of fully or partially porcelain-/glaze-veneered zirconia crowns after fatigue test. A sample of 60 first molars were selected and prepared for full-coverage crowns with three different designs (n = 20): traditional (crowns with zirconia framework covered with feldspathic porcelain), modified (crowns partially covered with veneering porcelain), and monolithic (full-contour zirconia crowns). All specimens were treated with a glaze layer. Specimens were subjected to mechanical cycling (100 N, 3 Hz) with a piston with a hemispherical tip (Ø = 6 mm) until the specimens failed or up to 2 × 10⁶ cycles. Every 500,000 cycles, the fatigue tests were interrupted and stereomicroscopy (10×) was used to inspect the specimens for damage. The authors performed Weibull analysis of interval data to calculate the number of failures in each interval. The types and numbers of failures according to the groups were: cracking (13 traditional, 6 modified) and chipping (4 traditional) of the feldspathic porcelain, followed by delamination (1 traditional) at the veneer/core interface and debonding (2 monolithic) at the cementation interface. Weibull parameters (β, scale; η, shape), with a two-sided confidence interval of 95%, were: traditional-1.25 and 0.9 × 10⁶ cycles; modified-0.58 and 11.7 × 10⁶ cycles; and monolithic-1.05 and 16.5 × 10⁶ cycles. Traditional crowns showed greater susceptibility to fatigue, the modified group presented higher propensity to early failures, and the monolithic group showed no susceptibility to fatigue. The modified and monolithic groups presented the highest number of crowns with no failures after the fatigue test. The three crown designs presented significantly different behaviors under fatigue. The modified and monolithic groups presented less probability of failure after 2 × 10⁶ cycles.
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Affiliation(s)
- G. Freitas Ramos
- Institute of Science and Technology, São Paulo State University (UNESP), Sao Jose dos Campos, Brazil
| | | | - M.A. Bottino
- Institute of Science and Technology, São Paulo State University (UNESP), Sao Jose dos Campos, Brazil
| | - Y. Zhang
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY 10010, USA
| | - R. Marques de Melo
- Institute of Science and Technology, São Paulo State University (UNESP), Sao Jose dos Campos, Brazil
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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.
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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
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Campos RE, Soares PV, Versluis A, de O. Júnior OB, Ambrosano GM, Nunes IF. Crown fracture: Failure load, stress distribution, and fractographic analysis. J Prosthet Dent 2015; 114:447-55. [DOI: 10.1016/j.prosdent.2015.02.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 02/26/2015] [Accepted: 02/27/2015] [Indexed: 10/23/2022]
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Sulaiman TA, Delgado AJ, Donovan TE. Survival rate of lithium disilicate restorations at 4 years: A retrospective study. J Prosthet Dent 2015; 114:364-6. [PMID: 26050028 DOI: 10.1016/j.prosdent.2015.04.011] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 04/17/2015] [Accepted: 04/22/2015] [Indexed: 10/23/2022]
Abstract
STATEMENT OF PROBLEM Ceramic restorations are frequently being placed due to the esthetic demand and the cost of noble metals that has increased considerably. One major disadvantage of ceramic restoration is failure of the material due to fracture by crack propagation. In vitro studies are of little clinical significance and in vivo studies are too short to support clinical success. PURPOSE The purpose of this retrospective study was to evaluate the failure rate of lithium disilicate restorations (monolithic and layered) at 4 years. MATERIAL AND METHODS Data were collected over 45 months from 2 commercial laboratories. Restorations were categorized into monolithic restorations and layered restorations. Each category was further classified into complete coverage single crowns, fixed dental prostheses, e.max veneers, and inlay/onlay restorations. Failure rates were compared and analyzed using Chi-square (α=.05). RESULTS A total of 21,340 restorations were evaluated in this study and included 15,802 monolithic restorations and 5538 layered restorations. The failure rate for single crown monolithic restorations was 0.91% and was 1.83% for single crown layered restorations. For fixed dental prostheses, 4.55% of monolithic restorations failed. For e.max veneers, 1.3% of monolithic veneers fractured and 1.53% of layered veneers fractured. Of the inlay/onlay restorations group, 1.01% of monolithic restorations fractured. CONCLUSION In the short term (45 months), restorations fabricated with the lithium disilicate material (IPS e.max) had relatively low fracture rates. Layered single crowns fractured at approximately 2 times the rate of monolithic crowns.
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Affiliation(s)
- Taiseer A Sulaiman
- Visiting scholar, Department of Operative Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, NC; and Doctoral student, Department of Prosthetic Dentistry, Institute of Dentistry, University of Turku, Turku, Finland
| | - Alex J Delgado
- Clinical Assistant Professor, Department of Restorative Sciences Division of Operative Dentistry, University of Florida, Gainesville, Fla.
| | - Terence E Donovan
- Professor and Section Head, Biomaterials Sciences, Department of Operative Dentistry, University of North Carolina, Chapel Hill, NC
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Creep-assisted slow crack growth in bio-inspired dental multilayers. J Mech Behav Biomed Mater 2015; 46:41-8. [DOI: 10.1016/j.jmbbm.2015.01.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 01/22/2015] [Accepted: 01/26/2015] [Indexed: 11/23/2022]
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43
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Slow cooling protocol improves fatigue life of zirconia crowns. Dent Mater 2015; 31:77-87. [DOI: 10.1016/j.dental.2014.10.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 12/22/2013] [Accepted: 10/27/2014] [Indexed: 11/18/2022]
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Majd B, Majd H, Porter JA, Romberg E, Arola D. Degradation in the fatigue strength of dentin by diamond bur preparations: Importance of cutting direction. J Biomed Mater Res B Appl Biomater 2015; 104:39-49. [PMID: 25611951 DOI: 10.1002/jbm.b.33348] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 11/16/2014] [Accepted: 12/02/2014] [Indexed: 11/12/2022]
Abstract
The objectives of this investigation were to evaluate the degradation in fatigue strength of dentin by diamond bur preparations and to identify the importance of cutting direction. Three groups of coronal dentin specimens were prepared from unrestored third molars, including a flaw free "control," and two groups that received a diamond bur cutting treatment performed parallel or perpendicular to the specimen length. The specimens were subjected to static or cyclic flexural loading to failure and the results were compared with data for carbide bur cutting. Under static loading diamond bur cutting resulted in significantly lower flexure strength (p ≤ 0.05) than the control for both cutting directions (from 154 to ∼124 MPa). However, there was no significant difference in the strength between the control and carbide bur treated specimens. Similarly, the fatigue strength of the diamond bur treated specimens was significantly lower (p ≤ 0.0001) than that of the control for both cutting directions. Cutting in the perpendicular direction resulted in nearly 60% reduction to the endurance limit (from 44 to 19 MPa). Based on the results, diamond bur cutting of cavity preparations causes a reduction in the fatigue strength of dentin, regardless of the cutting direction. To maintain the durability of dentin, cavity preparations introduced using diamond burs must be performed with appropriate cutting direction and followed by a finishing pass.
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Affiliation(s)
- B Majd
- Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, Maryland
| | - H Majd
- Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, Maryland
| | - J A Porter
- Department of Endodontics, Prosthodontics and Operative Dentistry, Dental School, University of Maryland, Baltimore, Maryland
| | - E Romberg
- Department of Endodontics, Prosthodontics and Operative Dentistry, Dental School, University of Maryland, Baltimore, Maryland
| | - D Arola
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington.,Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Washington
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45
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Rocha EP, Anchieta RB, de Almeida EO, Freitas AC, Martini AP, Sotto-Maior BS, Luersen MA, Ko CC. Zirconia-based dental crown to support a removable partial denture: a three-dimensional finite element analysis using contact elements and micro-CT data. Comput Methods Biomech Biomed Engin 2014; 18:1744-52. [DOI: 10.1080/10255842.2014.951927] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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46
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Saponaro PC, Heshmati RH, Lee DJ. Using a Porcelain Furnace to Debond Cement-Retained Implant Crown from the Abutment after Screw Fracture: A Clinical Report. J Prosthodont 2014; 24:239-42. [DOI: 10.1111/jopr.12233] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2014] [Indexed: 11/27/2022] Open
Affiliation(s)
- Paola C. Saponaro
- Resident, Advanced Prosthodontics Program; The Ohio State University College of Dentistry; Columbus OH
| | - Reza H. Heshmati
- Division of General Practice and Material Science; The Ohio State University College of Dentistry; Columbus OH
| | - Damian J. Lee
- Division of Restorative Sciences and Prosthodontics; The Ohio State University College of Dentistry; Columbus OH
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Oblak C, Verdenik I, Swain MV, Kosmac T. Survival-rate analysis of surface treated dental zirconia (Y-TZP) ceramics. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2014; 25:2255-2264. [PMID: 24781534 DOI: 10.1007/s10856-014-5217-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 04/11/2014] [Indexed: 06/03/2023]
Abstract
The role of surface preparation, hydrothermal ageing exposure and subsequent cyclic fatigue testing on the biaxial strength of a dental Y-TZP material are investigated. The initial strength and survival rate of a dental Y-TZP ceramic material to fatigue testing was found to be highly dependent upon surface preparation more so than exposure to various hydrothermal exposure conditions. The results suggest that the monoclinic phase generated by either surface damage (especially sandblasting) and to a lesser extent hydrothermal exposure does appear to mitigate strength and fatigue degradation. The results are discussed in terms of the size of defects generated following various surface treatments and the role of cyclic fatigue induced crack growth. A critical ratio is established between the monotonic strength and fatigue stress survival. From the specimens that failed and exhibited reduced strength after cycling a plot of averaged crack growth rate versus max cyclic stress intensity factor was established which closely matched existing results for Y-TZP ceramics.
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Affiliation(s)
- Cedomir Oblak
- Department of Prosthodontics, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
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48
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Al-Maqtari AA, Razak AAA, Hamdi M. 3D Finite element analysis of functionally graded multilayered dental ceramic cores. Dent Mater J 2014; 33:458-65. [PMID: 25087658 DOI: 10.4012/dmj.2013-251] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study aimed at investigating and establishing stress distributions in graded multilayered zirconia/alumina ceramic cores and at veneer-core-cement-dentin interfaces, using finite element analysis (FEA), to facilitate the structural design of ceramic cores through computer modeling. An intact maxillary premolar was digitized using CT scanning. An imaging software, Mimics, was used to reconstruct 3D models based on computed tomography (CT) data saved in DICOM format. Eight different 3D models were created for FEA, where each 3D model was meshed and its bottom boundaries constrained. A static load was applied in the oblique direction. The materials were assumed to be isotropic and homogeneous. Highest von Mises stress values were found in areas directly below the load application point, and stress gradually decreased in occlusal loading direction from the external surface toward the dentin. Stress levels occurring at veneer-ceramic core-cement-dentin interfaces were shown to be lower in multilayered ceramic cores than in single-layer models.
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49
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Abstract
The objective of this study was to evaluate the potential of a survival prediction method for the assessment of ceramic dental restorations. For this purpose, fast-fracture and fatigue reliabilities for 2 bilayer (metal ceramic alloy core veneered with fluorapatite leucite glass-ceramic, d.Sign/d.Sign-67, by Ivoclar; glass-infiltrated alumina core veneered with feldspathic porcelain, VM7/In-Ceram Alumina, by Vita) and 3 monolithic (leucite-reinforced glass-ceramic, Empress, and ProCAD, by Ivoclar; lithium-disilicate glass-ceramic, Empress 2, by Ivoclar) single posterior crown restorations were predicted, and fatigue predictions were compared with the long-term clinical data presented in the literature. Both perfectly bonded and completely debonded cases were analyzed for evaluation of the influence of the adhesive/restoration bonding quality on estimations. Material constants and stress distributions required for predictions were calculated from biaxial tests and finite element analysis, respectively. Based on the predictions, In-Ceram Alumina presents the best fast-fracture resistance, and ProCAD presents a comparable resistance for perfect bonding; however, ProCAD shows a significant reduction of resistance in case of complete debonding. Nevertheless, it is still better than Empress and comparable with Empress 2. In-Ceram Alumina and d.Sign have the highest long-term reliability, with almost 100% survivability even after 10 years. When compared with clinical failure rates reported in the literature, predictions show a promising match with clinical data, and this indicates the soundness of the settings used in the proposed predictions.
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Affiliation(s)
- H Lekesiz
- Bursa Technical University, Department of Mechanical Engineering, Gaziakdemir Mah. Mudanya Cad. No: 4/10 Osmangazi, Bursa, Turkey
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Degradation in the fatigue strength of dentin by cutting, etching and adhesive bonding. Dent Mater 2014; 30:1061-72. [PMID: 24985539 DOI: 10.1016/j.dental.2014.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 06/07/2014] [Accepted: 06/09/2014] [Indexed: 11/20/2022]
Abstract
UNLABELLED The processes involved in placing resin composite restorations may degrade the fatigue strength of dentin and increase the likelihood of fractures in restored teeth. OBJECTIVE The objective of this study was to evaluate the relative changes in strength and fatigue behavior of dentin caused by bur preparation, etching and resin bonding procedures using a 3-step system. METHODS Specimens of dentin were prepared from the crowns of unrestored 3rd molars and subjected to either quasi-static or cyclic flexural loading to failure. Four treated groups were prepared including dentin beams subjected to a bur treatment only with a conventional straight-sided bur, or etching treatment only. An additional treated group received both bur and etching treatments, and the last was treated by bur treatment and etching, followed by application of a commercial resin adhesive. The control group consisted of "as sectioned" dentin specimens. RESULTS Under quasi-static loading to failure there was no significant difference between the strength of the control group and treated groups. Dentin beams receiving only etching or bur cutting treatments exhibited fatigue strengths that were significantly lower (p≤0.0001) than the control; there was no significant difference in the fatigue resistance of these two groups. Similarly, the dentin receiving bur and etching treatments exhibited significantly lower (p≤0.0001) fatigue strength than that of the control, regardless of whether an adhesive was applied. SIGNIFICANCE The individual steps involved in the placement of bonded resin composite restorations significantly decrease the fatigue strength of dentin, and application of a bonding agent does not increase the fatigue strength of dentin.
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