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Htat HL, Takaichi A, Kajima Y, Kittikundecha N, Kamijo S, Hanawa T, Wakabayashi N. Influence of stress-relieving heat treatments on the efficacy of Co-Cr-Mo-W alloy copings fabricated using selective laser melting. J Prosthodont Res 2024; 68:310-318. [PMID: 37438109 DOI: 10.2186/jpr.jpr_d_22_00283] [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] [Indexed: 07/14/2023]
Abstract
Purpose This study aimed to evaluate the influence of stress-relieving heat treatments on the metal-ceramic bond strength and fitness accuracy of selective laser melting (SLM)-fabricated Co-Cr alloy copings.Methods SLM-manufactured Co-Cr samples were stress-relieved at 750 (Ht-750) and 1150 °C (Ht-1150). The microstructure, surface roughness, metal-ceramic bond strength, marginal and internal fit, Vickers hardness, and residual stress were then compared with those of the non-heat-treated group (As-built). The results were analyzed using one-way ANOVA and post-hoc tests (Tukey's or Student's t test) (P = 0.05).Results The microstructure of the Ht-1150 samples had a brittle oxide layer and lower surface roughness, resulting in significantly lower bond strength values than those of the other groups. The As-built group exhibited significantly lower marginal gap values than the Ht-750 and Ht-1150 groups. Therefore, the post-heat treatments degraded the marginal fitness. The surface residual stress in all sample groups were compressive because of the sandblasting effect. The compressive stresses were larger in Ht-1150 than in As-built and Ht-750 owing to their low hardness values.Conclusions Stress-relief annealing porcelain-fused-to-metal single crowns does not improve bond strength and degrades fitness accuracy because additional post-heat treatments induce thermal distortion. These findings are expected to facilitate the direct application of As-built SLM single crowns in dentistry to minimize post-manufacturing costs and time.
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Affiliation(s)
- Hein Linn Htat
- Department of Advanced Prosthodontics, Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Atsushi Takaichi
- Department of Advanced Prosthodontics, Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yuka Kajima
- Department of Advanced Prosthodontics, Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Nuttaphon Kittikundecha
- Department of Conservative Dentistry and Prosthodontics, Faculty of Dentistry, Srinakharinwirot University, Bangkok, Thailand
| | - Shingo Kamijo
- Basic Oral Health Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takao Hanawa
- Department of Metallic Biomaterials, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan
| | - Noriyuki Wakabayashi
- Department of Advanced Prosthodontics, Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
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Gama LT, Bezerra AP, Schimmel M, Rodrigues Garcia RCM, de Luca Canto G, Gonçalves TMSV. Clinical performance of polymer frameworks in dental prostheses: A systematic review. J Prosthet Dent 2024; 131:579-590. [PMID: 35422333 DOI: 10.1016/j.prosdent.2022.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 12/11/2022]
Abstract
STATEMENT OF PROBLEM High-performance polymers including polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) have been used as substitutes for metal frameworks in dental prostheses. However, the clinical performance of polymer-based frameworks is still uncertain. PURPOSE The purpose of this systematic review was to compare the clinical performance of PEEK and PEKK with that of metal frameworks for different dental prostheses. MATERIAL AND METHODS This review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Six databases and non-peer-reviewed literature (without language or follow-up restrictions) were searched for studies conducted before February 2022. Only clinical studies, either randomized clinical trials (RCTs) or nonrandomized clinical trials (N-RCTs), comparing the clinical performance of polymer and metal frameworks were included. The risk of bias and certainty of the evidence were assessed with the RoB 2.0, ROBINS-I, and GRADE. Biologic (plaque and gingival indices, probing depth, bleeding scores, implant stability quotient, marginal bone loss) and mechanical outcomes (ridge base relation, prosthetic marginal gap, and fracture) were assessed. RESULTS Only 9 studies (7 RCTs and 2 N-RCTs) were included, all with moderate to serious risk of bias and low to very low certainty of evidence. No meta-analysis was possible, but qualitative analysis revealed lower plaque and gingival indices, probing depth, and marginal bone loss, with higher survival rates for implant-supported fixed prostheses and overdentures fabricated with PEEK than for metal frameworks. No significant differences were found between groups for removable partial dentures. The marginal fit of PEEK frameworks was also better for single crowns. Three fractures were reported in the 3 PEKK fixed dental prostheses with cantilevers. CONCLUSIONS PEEK and PEKK seem to be promising materials for dental prostheses, with acceptable response from the periodontal tissue. However, further well-designed studies are necessary to better understand their clinical and long-term limitations.
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Affiliation(s)
- Lorena Tavares Gama
- PhD student, Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, São Paulo, Brazil
| | - Adriana Pinto Bezerra
- PhD student, Department of Dentistry, Federal University of Santa Catarina (UFSC), Florianópolis, Santa Catarina, Brazil
| | - Martin Schimmel
- Full Professor, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern (UNIBE), Bern, Switzerland; Division of Gerodontology and Removable Prosthodontics, University Clinics of Dental Medicine, University of Geneva (UNIGE), Geneva, Switzerland
| | - Renata Cunha Matheus Rodrigues Garcia
- Full Professor, Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, São Paulo, Brazil
| | - Graziela de Luca Canto
- Full Professor, Department of Dentistry, Federal University of Santa Catarina (UFSC), Florianópolis, Santa Catarina, Brazil
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Al Helou H, Kassis J, Zaidani W, Bylasani T. The effect of repeated baking of porcelain on its bonding strength to a Co-Cr alloy 3D-printed by selective laser melting. Saudi Dent J 2024; 36:296-300. [PMID: 38419985 PMCID: PMC10897619 DOI: 10.1016/j.sdentj.2023.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 03/02/2024] Open
Abstract
Objectives This study aimed to evaluate the effect of multiple baking cycles of porcelain on its shear bond strength to a cobalt-chromium (Co-Cr) alloy that is three-dimensionally printed using Selective Laser Melting (SLM) technique. Materials and methods The research sample comprised forty-eight discs measuring 5 mm × 3 mm, divided into four groups according to: the manufacturing method (SLM, casting) and the number of porcelain baking cycles (1, 3) as follows: Group A: Co-Cr alloy by SLM with one baking cycle; Group B: Co-Cr alloy by SLM with three baking cycles; Group C: Ni-Cr alloy by casting with one baking cycle; Group D: Ni-Cr alloy by casting with three baking cycles. Then, porcelain was melted on disks, shear testing was performed and the values of the Shear Bond Strength (SBS) in MegaPascals (MPa) were calculated. Results The mean SBS values for each group were (A: 25.69 - B: 19.51 - C: 35.72 - D: 28.67 MPa). Statistical analysis showed that the manufacturing method and the number of porcelain baking cycles had a significant influence on shear bond durability (P > 0.05): the strength of this bond decreased when baking cycles increased. The Co-Cr samples manufactured by SLM also showed a decrease in binding strength compared to the Ni-Cr samples made by casting. Conclusion Repeated baking of porcelain reduces the strength of the porcelain bond with the Co-Cr alloy made by Selective Laser Melting (SLM) technique.
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Affiliation(s)
- Hiba Al Helou
- Head of the Department of Prosthodontics at Arab Private University of Science and Technology (AUST), Hama Homs international road, Tel Qartal Junction, Syria
| | - Joul Kassis
- Researcher at the Department of Oral and Maxillofacial Surgery, Damascus University, Fayez Mansour Highway, Mazzeh, Damascus, Syria
| | - Wael Zaidani
- Dental student at Arab Private University of Science and Technology (AUST), Hama Homs international road, Tel Qartal Junction, Syria
| | - Tareq Bylasani
- Dental student at Arab University of Science and Technology (AUST), Hama Homs international road, Tel Qartal Junction, Syria
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Giti R, Hosseinpour Aghaei M, Mohammadi F. The effect of repeated porcelain firings on the marginal fit of millable and conventional casting alloys. PLoS One 2023; 18:e0275374. [PMID: 37874843 PMCID: PMC10597472 DOI: 10.1371/journal.pone.0275374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 09/15/2022] [Indexed: 10/26/2023] Open
Abstract
The durability of dental restorations is highly determined by an accurate marginal fit, which is in turn affected by the high temperature of porcelain firing. Information is inadequate about the marginal adaptation of metal-ceramic restorations fabricated by soft metal milling technologies after repeated firings. This study aimed to compare the effect of repeated ceramic firings on the marginal fit of copings fabricated from cobalt-chromium through soft metal milling and a conventional nickel-chromium casting alloy. A single standard brass die was designed, machined, and scanned, based on which, 20 frameworks were designed and fabricated through either soft metal milling or conventional casting (n = 10 per group) and porcelain veneered. The vertical marginal fit of the metal copings was measured after 3, 5, and 7 firing cycles by using a digital microscope on 16 points around the finish line of the metal die at ×80 magnification. The data were analyzed through repeated measures ANOVA and independent t-test (α = 0.05). The marginal fit of neither metal group was significantly affected by the number of firing cycles (P = 0.747). However, the marginal discrepancy was statistically lower in the soft metal milling group than that in the casting group (P<0.001). Repeated porcelain firings did not significantly affect the marginal fit of either alloy and remained within the clinically acceptable range after firings. However, the milled alloy had superior marginal fit regardless of the number of firing cycles.
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Affiliation(s)
- Rashin Giti
- Department of Prosthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Fars, Iran
| | - Mahdi Hosseinpour Aghaei
- Student Research Committee, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Fars, Iran
| | - Farhad Mohammadi
- Department of Pharmaceutics, School of Pharmacy, Shahid Sadoughi University of Medical Sciences and Health Care Services, Yazd, Iran
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Tomova Z, Chonin A, Stoeva I, Vlahova A. Clinical and laboratory study of corrosion resistance of a base dental alloy for selective laser melting. Folia Med (Plovdiv) 2023; 65:664-670. [PMID: 37655388 DOI: 10.3897/folmed.65.e73531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 03/16/2023] [Indexed: 09/02/2023] Open
Abstract
INTRODUCTION CAD/CAM technologies are becoming widely used for the production of metal ceramic dental restorations. Powder Co-based alloys are developed for selective laser melting. The corrosion resistance of the dental alloy affects the biocompatibility, functional suitability, and longevity of the prosthetic restoration.
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Dawod N, Miculescu M, Antoniac IV, Miculescu F, Agop-Forna D. Metal-Ceramic Compatibility in Dental Restorations According to the Metallic Component Manufacturing Procedure. MATERIALS (BASEL, SWITZERLAND) 2023; 16:5556. [PMID: 37629847 PMCID: PMC10456282 DOI: 10.3390/ma16165556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/03/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023]
Abstract
In terms of production technology, metal-ceramic systems for dental restorations comply with a concrete algorithm, the efficiency of which is always dependent on the applications for which they are intended. The first stage involves obtaining metal support, followed by firing the ceramic on the surface of the metal to meet the list of functional and aesthetic requirements of a future restoration. The compatibility of the two materials-the metal component and the ceramic component-must be ensured in several respects: chemical compatibility, thermo-chemical compatibility, and mechanical compatibility. Thus, there is a need to simulate the thermal behavior of the metal-ceramic couple in its processing to achieve appropriate dental prostheses. In this study, three types of Co-Cr metal frames were manufactured using three different production technologies: conventional casting, milling (CAM), and selective laser melting (SLM). Composition analyses, scanning electron microscopy (SEM), and microstructural analyses of the metal-ceramic interface for each type of production technology, as well as the determination of the hardness and the thermal expansion coefficients of experimental materials and three-point bending tests, were carried out in this study. Considering all these aspects, we demonstrated the influence of the technology of producing the metallic part of the metal-ceramic bonding process in dental prostheses.
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Affiliation(s)
- Nazem Dawod
- Faculty of Material Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, District 6, 060042 Bucharest, Romania; (N.D.); (I.V.A.); (F.M.)
- SC Sesene Dent SRL, 37 Vulcan Judetul Street, District 3, 030055 Bucharest, Romania
| | - Marian Miculescu
- Faculty of Material Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, District 6, 060042 Bucharest, Romania; (N.D.); (I.V.A.); (F.M.)
| | - Iulian Vasile Antoniac
- Faculty of Material Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, District 6, 060042 Bucharest, Romania; (N.D.); (I.V.A.); (F.M.)
- Academy of Romanian Scientists, 54 Splaiul Independentei, 050094 Bucharest, Romania
| | - Florin Miculescu
- Faculty of Material Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, District 6, 060042 Bucharest, Romania; (N.D.); (I.V.A.); (F.M.)
| | - Doriana Agop-Forna
- “Gr.T. Popa” University of Medicine and Pharmacy, 16 Universității Street, 700115 Iași, Romania;
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Tomova Z, Vlahova A, Zlatev S, Stoeva I, Tomov D, Davcheva D, Hadzhigaev V. Clinical Evaluation of Corrosion Resistance, Ion Release, and Biocompatibility of CoCr Alloy for Metal-Ceramic Restorations Produced by CAD/CAM Technologies. Dent J (Basel) 2023; 11:166. [PMID: 37504232 PMCID: PMC10378696 DOI: 10.3390/dj11070166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/30/2023] [Accepted: 07/04/2023] [Indexed: 07/29/2023] Open
Abstract
BACKGROUND CAD/CAM technologies facilitate using powder CoCr alloys to produce metal-ceramic dental restorations. However, base alloys may induce oxidative stress in the oral cavity due to corrosion and ion release. This study evaluated resistance to corrosion and release of metal ions from 3D printed CoCr dental alloy and their effect on oral oxidative stress. METHODS Metal-ceramic crowns with 3D printed copings from CoCr alloy EOS CobaltChrome SP2 (EOS, Germany) were fabricated for 35 patients. Inductively coupled plasma mass spectrometry (ICP-MS) was used for measuring the concentration of Co and Cr ions in non-stimulated saliva before prosthetic treatment (BPT), at 2 h and 7 days after the dental treatment (APT2, APT7, respectively). Open circuit potentials (Eocp) were evaluated at APT2 and APT7. Estimating oral oxidative stress, measurements of 8-isoprostaglandin F2-alpha were conducted using liquid chromatography-tandem mass spectrometry (LC-MS/MS) at stages BPT, APT2, and APT7. RESULTS Salivary Co level increased at APT2 and decreased to the initial levels at APT7. No statistical difference was found between the levels of 8-isoPGF2-alpha measured, and between the Eocp measurements at APT2 and APT7. CONCLUSIONS The studied alloy showed stable corrosion resistance and the metal ion release did not induce oral oxidative stress.
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Affiliation(s)
- Zlatina Tomova
- Department of Prosthetic Dental Medicine, Faculty of Dental Medicine, Medical University of Plovdiv, 3, Hristo Botev blvd, 4002 Plovdiv, Bulgaria
| | - Angelina Vlahova
- Department of Prosthetic Dental Medicine, Faculty of Dental Medicine, Medical University of Plovdiv, 3, Hristo Botev blvd, 4002 Plovdiv, Bulgaria
| | - Stefan Zlatev
- Department of Prosthetic Dental Medicine, Faculty of Dental Medicine, Medical University of Plovdiv, 3, Hristo Botev blvd, 4002 Plovdiv, Bulgaria
| | - Ilyana Stoeva
- Department of Diagnostic Imaging, Dental Allergology and Physiotherapy, Faculty of Dental Medicine, Medical University of Plovdiv, 3, Hristo Botev blvd, 4002 Plovdiv, Bulgaria
| | - Desislav Tomov
- Department of Bioorganic Chemistry, Faculty of Pharmacy, Medical University of Plovdiv, 15-A "Vasil Aprilov" blvd, 4002 Plovdiv, Bulgaria
| | - Delyana Davcheva
- Department of Clinical Laboratory, Faculty of Pharmacy, University Multi-Profile Hospital for Active Treatment St. George Plovdiv, Research Institute at Medical University of Plovdiv, Medical University of Plovdiv, 15-A "Vasil Aprilov" blvd, 4002 Plovdiv, Bulgaria
| | - Viktor Hadzhigaev
- Department of Prosthetic Dental Medicine, Faculty of Dental Medicine, Medical University of Plovdiv, 3, Hristo Botev blvd, 4002 Plovdiv, Bulgaria
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Cai H, Xu X, Lu X, Zhao M, Jia Q, Jiang HB, Kwon JS. Dental Materials Applied to 3D and 4D Printing Technologies: A Review. Polymers (Basel) 2023; 15:polym15102405. [PMID: 37242980 DOI: 10.3390/polym15102405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 05/09/2023] [Accepted: 05/17/2023] [Indexed: 05/28/2023] Open
Abstract
As computer-aided design and computer-aided manufacturing (CAD/CAM) technologies have matured, three-dimensional (3D) printing materials suitable for dentistry have attracted considerable research interest, owing to their high efficiency and low cost for clinical treatment. Three-dimensional printing technology, also known as additive manufacturing, has developed rapidly over the last forty years, with gradual application in various fields from industry to dental sciences. Four-dimensional (4D) printing, defined as the fabrication of complex spontaneous structures that change over time in response to external stimuli in expected ways, includes the increasingly popular bioprinting. Existing 3D printing materials have varied characteristics and scopes of application; therefore, categorization is required. This review aims to classify, summarize, and discuss dental materials for 3D printing and 4D printing from a clinical perspective. Based on these, this review describes four major materials, i.e., polymers, metals, ceramics, and biomaterials. The manufacturing process of 3D printing and 4D printing materials, their characteristics, applicable printing technologies, and clinical application scope are described in detail. Furthermore, the development of composite materials for 3D printing is the main focus of future research, as combining multiple materials can improve the materials' properties. Updates in material sciences play important roles in dentistry; hence, the emergence of newer materials are expected to promote further innovations in dentistry.
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Affiliation(s)
- HongXin Cai
- Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 03722, Republic of Korea
| | - Xiaotong Xu
- The CONVERSATIONALIST Club, School of Stomatology, Shandong First Medical University, Jinan 250117, China
| | - Xinyue Lu
- The CONVERSATIONALIST Club, School of Stomatology, Shandong First Medical University, Jinan 250117, China
| | - Menghua Zhao
- The CONVERSATIONALIST Club, School of Stomatology, Shandong First Medical University, Jinan 250117, China
| | - Qi Jia
- The CONVERSATIONALIST Club, School of Stomatology, Shandong First Medical University, Jinan 250117, China
| | - Heng-Bo Jiang
- The CONVERSATIONALIST Club, School of Stomatology, Shandong First Medical University, Jinan 250117, China
| | - Jae-Sung Kwon
- Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 03722, Republic of Korea
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Choi JH, Heo SJ, Koak JY, Kim SK, Park JM, Ahn JS. Effect of hemispherical dimples at titanium implant abutments for the retention of cemented crowns. J Adv Prosthodont 2023; 15:63-71. [PMID: 37153008 PMCID: PMC10154144 DOI: 10.4047/jap.2023.15.2.63] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 12/06/2022] [Accepted: 01/31/2023] [Indexed: 05/09/2023] Open
Abstract
PURPOSE The aim of this study was to assess the effect of hemispherical dimple structures on the retention of cobalt-chromium (Co-Cr) crowns cemented to titanium abutments, with different heights and numbers of dimples on the axial walls. MATERIALS AND METHODS 3.0-mm and 6.0-mm abutments (N = 180) and Co-Cr crowns were prepared. The experimental groups were divided into two and four dimple groups. The crowns were cemented by TempBond and PANAVIA F 2.0 cements. The retention forces were measured after thermal treatments. A two-way Analysis of Variance (ANOVA) and post-hoc Tukey HSD test were conducted to analyze change in retention forces by use of dimples between groups, as well as t test for the effect of abutment height change (α = .05). RESULTS Results of the two-way ANOVA showed a statistically significant difference in retention force due to the use of dimples, regardless of the types of cements used (P < .001). A significantly higher mean retention forces were observed in the groups with dimples than in the control group, using the post hoc Tukey HSD test (P < .001). Results of t test displayed a statistically significant increase in the retention force with 6.0-mm abutments compared with 3.0-mm abutments (P < .001). The groups without dimples revealed adhesive failure of cements, while the groups with dimples showed mixed failure of cements. CONCLUSION Use of hemispherical dimples was effective for increasing retention forces of cemented crowns.
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Affiliation(s)
- Jung-Hoon Choi
- Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Seong-Joo Heo
- Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Jai-Young Koak
- Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Seong-Kyun Kim
- Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Ji-Man Park
- Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Jin-Soo Ahn
- Department of Dental Biomaterials Science and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
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Characterization of Co-Cr-W Dental Alloys with Veneering Materials Manufactured via Subtractive Milling and Additive Manufacturing LDED Methods. MATERIALS 2022; 15:ma15134624. [PMID: 35806747 PMCID: PMC9267738 DOI: 10.3390/ma15134624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/27/2022] [Accepted: 06/29/2022] [Indexed: 11/25/2022]
Abstract
Laser-directed energy deposition (LDED) is an additive manufacturing (AM) technology which can be an alternative to the traditional subtractive milling process for the obtention of porcelain-fused-to-metal (PFM) prosthesis. Still, the adhesion performance of the veneering ceramics for this material has been not studied yet. The main objective of this study is to perform a systematic comparison of the adhesion performance of Co-Cr-W metal frameworks obtained through LDED and conventional milling techniques. Comparison includes microstructural, superficial, and adhesion analysis. Co-Cr manufactured via LDED technique presents similar behavior (p < 0.05) in comparison to the material obtained via milling techniques, and its performance was validated with the veneering ceramics and veneering composites currently employed in the dental industry.
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Analysis of microstructure and fatigue of cast versus selective laser-melted dental Co-Cr alloy. J Prosthet Dent 2022; 128:218.e1-218.e7. [PMID: 35786348 DOI: 10.1016/j.prosdent.2022.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 05/24/2022] [Accepted: 05/24/2022] [Indexed: 11/22/2022]
Abstract
STATEMENT OF PROBLEM The forces exerted on teeth and prostheses during mastication are repeated and dynamic, resulting in fatigue damage to dental prostheses. Most fractures of dental restorations are fatigue failure. The 4-point bend fatigue behavior of Co-Cr-Mo-W alloys manufactured by investment casting (CAST) and selective laser melting (SLM) has received little attention. PURPOSE The purpose of this in vitro study was to evaluate the 4-point bend fatigue property of dental Co-Cr alloys and determine the relationship between microstructure and the 4-point bend fatigue property of Co-Cr alloys created by traditional casting and SLM. These can guide the use of Co-Cr alloy in dentistry. MATERIAL AND METHODS Co-Cr-Mo-W alloys were fabricated with a dimension of 45×2×2 mm by investment casting and SLM. The 3-point bend test measured the ultimate bend strength with 3 specimens in each group. The 4-point bend fatigue test evaluated the fatigue life under various stresses, with 6 specimens in each group. The specimens were mechanically ground, polished, and electrochemically etched. Scanning electron microscopy was used to identify the microstructures of both etched specimens and fracture surfaces. X-ray diffraction investigations were used to determine the phases. Significant differences in the bend strength were analyzed by using the independent samples t test (α=.05), and the fatigue test was analyzed with ANCOVA (α=.05). RESULTS The mean ±standard deviation bend strength of SLM specimens was 1837 ±3 MPa, higher than the 1200 ±6 MPa for CAST specimens (P<.05). The maximum bend stress of the SLM specimens without fatigue failure was 735 MPa, which was statistically higher than the 394 MPa for CAST specimens (P<.05). The microstructure characteristics of the SLM alloy contributed to its excellent fatigue performance. In SLM alloy, the γ phase constituted the majority with some ε and Laves phases, while the cast alloy possessed higher ε and Laves phases. The grains of SLM alloy were equiaxed and fine, and the second phases were fine and dispersive. In contrast, the cast alloy possessed clear dendrites, and the second phases were sizable. CONCLUSIONS The SLM dental Co-Cr-Mo-W alloy had statistically better 4-point bend fatigue properties than cast alloy, which was associated with an improved microstructure.
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An In Vitro Study on the Shear Bond Strength of Feldspathic Porcelain to Nickel Chromium Alloy and Cobalt Chromium Alloy after Various Surface Treatments. Int J Dent 2022; 2022:2557127. [PMID: 35677808 PMCID: PMC9170503 DOI: 10.1155/2022/2557127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/30/2022] [Accepted: 05/05/2022] [Indexed: 11/18/2022] Open
Abstract
Background To evaluate and compare the shear bond strength of feldspathic porcelain to four distinctively surface-treated Ni-Cr and Co-Cr alloys and to assess the impact of oxidation-heat treatment on porcelain to base metal alloy bond strength. Methods 40 specimens each of nickel-chromium alloy and cobalt-chromium alloy were cast. A total of four groups of specimens were created. Group I was surface-treated by sandblasting with 50 μm alumina particles, Group II was surface-treated by sandblasting with 110 μm alumina particles, Group III and Group IV were surface-treated with 250 μm alumina particles. In Group IV, after sandblasting initially with 250 μm alumina particles, the alloys were subjected to oxidation and resandblasting with 250 μm alumina particles. Each of the specimen was coated with opaque and body porcelain and fired to a total thickness of 2 mm porcelain. A universal measuring machine was used to assess shear bond strength at a crosshead speed of 0.5 mm/min. Results Two-way ANOVA followed by Tukey's post hoc test was used to assess the significant difference within the groups. Unpaired t-test was used for the intergroup comparison of the obtained data. The study showed that the size of the air abrasion particles used for sandblasting significantly influenced the porcelain to metal surface bond strength, with p value <0.001. The bond strength values of the two alloys tested showed no major variations. Result also showed that oxidation influences the metal-ceramic bond strength. Conclusions The bond strength of the metal-ceramic interface is influenced by the alloy's surface treatment. The oxidation process impacts the bond strength of the metal-ceramic system.
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Tobar C, Rodriguez V, Lopez-Suarez C, Pelaez J, Suarez MJ. Influence of Digital Technologies and Framework Design on the Load to Fracture of Co-Cr Posterior Fixed Partial Denture Frameworks. J Prosthodont 2021; 31:606-613. [PMID: 34860426 DOI: 10.1111/jopr.13458] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2021] [Indexed: 12/01/2022] Open
Abstract
PURPOSE To compare the load to fracture of cobalt-chromium (Co-Cr) 3-unit posterior fixed partial denture (FPD) frameworks manufactured by conventional and digital techniques and to evaluate the influence of the framework design on the fracture load. MATERIAL AND METHODS Eighty 3-unit Co-Cr posterior FPD frameworks were fabricated with two designs: intermediate pontic (n = 40) and cantilever (n = 40). Each design was randomly divided into four groups (n = 10): casting, direct metal laser sintering, soft metal milling, and hard metal milling. After thermal cycling, all specimens were subjected to a 3-point bending test until fracture. Data were statistically analyzed using one-way ANOVA, Welch and Brown-Forsythe test, Ryan-Einot-Gabriel-Welsch F and Tamhane T2 post hoc test, Student's t test, and Weibull statistics (α = 0.05). RESULTS Significant differences (p < 0.001; F = 39.59) were found among intermediate pontic frameworks (except between laser sintering and hard metal milling), and cantilevered frameworks (F = 36.75) (except between laser sintering and hard metal milling, and casting and soft metal milling). The cantilever groups showed load to fracture values significantly lower than those of the intermediate pontic (p < 0.001; F = 28.29). The Weibull statistics corroborated the results. CONCLUSIONS Hard metal milling and laser sintered frameworks exhibited the highest load to fracture values. However, all tested frameworks demonstrated clinically acceptable load to fracture values. The framework design directly affected the fracture load, with drastically lower values in cantilevered frameworks.
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Affiliation(s)
- Celia Tobar
- Department of Conservative Dentistry and Buccofacial Prostheses, Faculty of Odontology, University Complutense of Madrid, Madrid, Spain
| | - Veronica Rodriguez
- Department of Conservative Dentistry and Buccofacial Prostheses, Faculty of Odontology, University Complutense of Madrid, Madrid, Spain
| | - Carlos Lopez-Suarez
- Department of Conservative Dentistry and Buccofacial Prostheses, Faculty of Odontology, University Complutense of Madrid, Madrid, Spain
| | - Jesus Pelaez
- Department of Conservative Dentistry and Buccofacial Prostheses, Faculty of Odontology, University Complutense of Madrid, Madrid, Spain
| | - Maria J Suarez
- Department of Conservative Dentistry and Buccofacial Prostheses, Faculty of Odontology, University Complutense of Madrid, Madrid, Spain
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Gundogdu M, Cansever S, Karaavcı MS, Ertas U. Implant-Prosthetic Rehabilitation of a Patient with Squamous Cell Carcinoma: A Case Report. J ORAL IMPLANTOL 2021; 48:215-219. [PMID: 33945615 DOI: 10.1563/aaid-joi-d-20-00324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Patients who have undergone maxillary resection procedures are rehabilitated with dental obturators or microvascular reconstruction. This case report describes implant-supported prosthetic rehabilitation of a patient who underwent maxillary resection due to squamous cell carcinoma. After maxillectomy surgery, the patient was rehabilitated using a surgical obturator for one week followed by an interim obturator until the surgical field was completely healed. For definitive prosthesis, different treatment options were presented from which the patient selected an implant-supported maxillofacial prosthesis and a removable mandibular partial prosthesis. Under general anesthesia, two zygomatic implants and four conventional implants to the posterior maxilla were inserted. After a healing period, the bar-retained maxillofacial prosthesis and removable mandibular partial denture were fabricated. The patient was satisfied with regard to function, esthetics, speech, and swallowing. No problems, except slight discoloration of the prosthesis were noted at the 6-month follow-up. Implant-supported maxillofacial prostheses are a valuable treatment option to improve quality of life after maxillary resection.
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Affiliation(s)
- Mustafa Gundogdu
- Atatürk University Faculty of Dentistry Prosthodontics Atatürk University Faculty of Dentistry Department of Prosthodontics TURKEY Erzurum Yakutiye 25240 Atatürk University Faculty of Dentistry
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Fracture Load of Metal, Zirconia and Polyetheretherketone Posterior CAD-CAM Milled Fixed Partial Denture Frameworks. MATERIALS 2021; 14:ma14040959. [PMID: 33670544 PMCID: PMC7922591 DOI: 10.3390/ma14040959] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/10/2021] [Accepted: 02/15/2021] [Indexed: 01/02/2023]
Abstract
The aim of this study was to investigate the load to fracture and fracture pattern of prosthetic frameworks for tooth-supported fixed partial dentures (FPDs) fabricated with different subtractive computer-aided design and computer-aided manufacturing (CAD-CAM) materials. Materials and Methods: Thirty standardized specimens with two abutments were fabricated to receive three-unit posterior FDP frameworks with an intermediate pontic. Specimens were randomly divided into three groups (n = 10 each) according to the material: group 1 (MM)—milled metal; group 2 (L)—zirconia; and group 3 (P)—Polyetheretherketone (PEEK). The specimens were thermo-cycled and subjected to a three-point bending test until fracture using a universal testing machine (cross-head speed: 1 mm/min). Axial compressive loads were applied at the central fossa of the pontics. Data analysis was made using one-way analysis of variance, Tamhane post hoc test, and Weibull statistics (α = 0.05). Results: Significant differences were observed among the groups for the fracture load (p < 0.0001). MM frameworks showed the highest fracture load values. The PEEK group registered higher fracture load values than zirconia samples. The Weibull statistics corroborated these results. The fracture pattern was different among the groups. Conclusions: Milled metal provided the highest fracture load values, followed by PEEK, and zirconia. However, all tested groups demonstrated clinically acceptable fracture load values higher than 1000 N. PEEK might be considered a promising alternative for posterior FPDs.
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