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1 – 10 of 173Urska Kostevsek, Tomaz Brajlih, Joze Balic, Žiga Kadivnik and Igor Drstvensek
Fixed structures in prosthetic dentistry are highly customized products, manufactured individually for patients who have missing teeth. When choosing the technology for fixed…
Abstract
Purpose
Fixed structures in prosthetic dentistry are highly customized products, manufactured individually for patients who have missing teeth. When choosing the technology for fixed dental structure manufacturing, three viable options are available (precise casting, milling and selective laser melting [SLM]). All these technologies can be used to produce a dental structure from CoCr alloy. Besides materials and availability of technologies, economic efficiency is an important factor when choosing a production method. The purpose of this study is to develop an estimation model for achievable productivity of selective laser melting and compare the results with the productivity of conventional manufacturing.
Design/methodology/approach
Results presented in this paper are based on manufacturing time analysis of an individual case with each of the technologies mentioned above. Because of the efficiency of SLM is highly dependent on how efficiently the work space of the machine is used, this issue was also included in the research. Data used for research were acquired from practical use of each technology in dental applications.
Findings
Analysis of achievable SLM manufacturing speeds is based on the previous research into manufacturing speeds of additive manufacturing technologies. The presented results present a model that can be used to estimate the productivity of the SLM technology.
Research limitations/implications
Research was limited to a specific SLM machine type with a fixed workspace volume. Nevertheless, the results show that any SLM machine has to be used as efficiently as possible to be able to be competitive regarding the conventional manufacturing technologies.
Practical implications
The presented results show clearly at least a rough estimation of what kind of parts and in what volume will be manufactured with an SLM machine prior to buying one.
Social implications
Results can help to widen the economically efficient way of running SLM machines, replacing conventional manufacturing for medical applications especially with complicated cases.
Originality/value
A method is presented to adapt the estimation model to a particular real-life production scenario. This method can be used to establish how efficiently selective laser sintering can be used and if using SLM machine instead of conventional manufacturing would be economically viable.
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Ana Carla Cordeiro, Gustavo George Verdieri Nuernberg, Lilian Cristina Côcco and Marlon Wesley Machado Cunico
Different technologies may currently be used to produce dental prostheses, such as additive manufacturing and traditional milling. This study aims to evaluate and improve the…
Abstract
Purpose
Different technologies may currently be used to produce dental prostheses, such as additive manufacturing and traditional milling. This study aims to evaluate and improve the fabrication process for hot-pressed porcelain dental prostheses and compare the use of masked stereolithography apparatus (MSLA) casting to computer-aided design/computer-aided manufacturing (CAD/CAM) casting. The cost-benefit analysis of producing dental prostheses through various technologies, including additive manufacturing and traditional milling, has not been fully explored. The cost of materials and processes used to produce prostheses varies based on complexity of design and materials used, and long-term effects, such as durability and wear and tear, must be taken into account.
Design/methodology/approach
Using key elements of part costs and estimation cost models, a multivariable approach was used to evaluate the practicality of the recommended strategy and process improvement.
Findings
The research found that MSLA casting provides a higher return on investment than CAD/CAM casting, and the optimized production process could be more suitable for the size and annual demand for prostheses.
Originality/value
Overall, this study highlights the need for a more comprehensive understanding of the cost-benefit analysis of different dental prosthesis production methods and emphasises the importance of evaluating long-term effects on the cost-benefit analysis.
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Wahyudin P. Syam, Huda A. Al‐Shehri, A.M. Al‐Ahmari, Khalid A. Al‐Wazzan and M.A. Mannan
The purpose of this paper is to investigate the potential application of electron beam melting, as a layered manufacturing process, to fabricate dental coping of metal‐ceramic…
Abstract
Purpose
The purpose of this paper is to investigate the potential application of electron beam melting, as a layered manufacturing process, to fabricate dental coping of metal‐ceramic crown restoration using Ti6Al4V powder.
Design/methodology/approach
This experiment was conducted in two steps: shrinkage study to determine scale up factor for shrinkage compensation and parameter selection study, based on thickness, hardness, and surface roughness, to select process parameter of electron beam melting.
Findings
A promising result of fabricating metal coping of Ti6Al4V via electron beam melting was shown. Ti6Al4V coping was successfully fabricated, with an average thickness of 0.52 mm required for dental coping. Total average hardness of 333.35 HV that is comparable to casted Ti6Al4V with considerably high roughness of RSm of 382 μm.
Originality/value
The paper presents a novel application of electron beam melting to fabricate metal coping for metal‐ceramic crown restoration.
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Three-dimensional (3D) printing technologies have gained attention in dentistry because of their ability to print objects with complex geometries with high precision and accuracy…
Abstract
Purpose
Three-dimensional (3D) printing technologies have gained attention in dentistry because of their ability to print objects with complex geometries with high precision and accuracy, as well as the benefits of saving materials and treatment time. This study aims to explain the principles of the main 3D printing technologies used for manufacturing dental prostheses and devices, with details of their manufacturing processes and characteristics. This review presents an overview of available 3D printing technologies and materials for dental prostheses and devices.
Design/methodology/approach
This review was targeted to include publications pertaining to the fabrication of dental prostheses and devices by 3D printing technologies between 2012 and 2021. A literature search was carried out using the Web of Science, PubMed, Google Scholar search engines, as well as the use of a manual search.
Findings
3D printing technologies have been used for manufacturing dental prostheses and devices using a wide range of materials, including polymers, metals and ceramics. 3D printing technologies have demonstrated promising experimental outcomes for the fabrication of dental prostheses and devices. However, further developments in the materials for fixed dental prostheses are required.
Originality/value
3D printing technologies are effective and commercially available for the manufacturing of polymeric and metallic dental prostheses. Although the printing of dental ceramics and composites for dental prostheses is promising, further improvements are required.
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Sara M. Martins, Fernando A.F. Ferreira, João J. M. Ferreira and Carla S.E. Marques
The prosthodontics sector is facing major challenges because of scientific and technological advances that imply a clearer definition of lines of action and decision making…
Abstract
Purpose
The prosthodontics sector is facing major challenges because of scientific and technological advances that imply a clearer definition of lines of action and decision making processes. Measuring quality of service in this sector is a complex decision problem since the perceptions of three main players need to be considered: patients, dentists and dental technicians. This study sought to develop an artificial-intelligence-based (AI-based) method for assessing service quality in the dental prosthesis sector.
Design/methodology/approach
Using strategic options development and analysis (SODA), which is grounded on cognitive mapping, and the measuring attractiveness by a categorical based evaluation technique (MACBETH), a constructivist decision support system was designed to facilitate the assessment of service quality in the dental prosthesis sector. The system was tested, and the results were validated both by the members of an expert panel and by the vice-president of the Portuguese association of dental prosthesis technicians.
Findings
The methodological process developed in this study is extremely versatile and its practical application facilitated the development of an empirically robust evaluation model in this study context. Specifically, the profile analyses carried out in actual clinics allowed the cases in which improvements are needed to be identified.
Originality/value
Although already applied in the fields of AI and decision making, no prior work reporting the use of SODA and MACBETH for assessing service quality in the prosthodontics sector has been found.
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Abdollah Afshar, Mohsen Shirazi, Masoud Rahman and Esmaeil Fakheri
The purpose of this paper is to evaluate the galvanic corrosion of nitinol orthodontic wires with six dental alloys in artificial saliva and consider the effect of initiated…
Abstract
Purpose
The purpose of this paper is to evaluate the galvanic corrosion of nitinol orthodontic wires with six dental alloys in artificial saliva and consider the effect of initiated localized corrosion and real surfaces of anode and cathode on galvanic current.
Design/methodology/approach
Linear polarization and cyclic polarization curves for each alloy in de‐aerated Duffo and Castillo's artificial saliva are obtained. Galvanic corrosion investigation is conducted by polarization curve intersection and mixed potential theory methods. In order to verify the initiation of localized corrosion, scanning electron microscopy is used.
Findings
Initiation of localized corrosion on the anode increases the galvanic current up to 45 times and therefore considering the effect of localized corrosion on galvanic corrosion is necessary. Placing stainless steel brackets or Aristaloy amalgam in direct contact to nitinol arch wire is not recommended.
Originality/value
In order not to underestimate the galvanic corrosion between two alloys, it is recommended to consider the effects of localized corrosion and anode/cathode surface area ratio. In this paper, an electrochemical method for estimating these factors is proposed.
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Qin Lian, Wenquan Sui, Xiangquan Wu, Fei Yang and Shaopeng Yang
This paper aims to develop an additive manufacturing technique for complex zirconia ceramic dental bridges.
Abstract
Purpose
This paper aims to develop an additive manufacturing technique for complex zirconia ceramic dental bridges.
Design/methodology/approach
To carry out this study, a dental bridge model was obtained by three-dimensional reverse engineering, and a light-curable zirconia ceramic suspension was formulated. Zirconia bridges were manufactured by stereolithography and then treated by vacuum freeze drying, vacuum infiltration and sintering. The optimal scanning speed was determined according to the shape precision comparison. Then, characteristics of the sintered ceramic parts were tested as size shrinkage, relative density, surface Vickers hardness, surface roughness and microstructure.
Findings
The method for preparation of light-curable zirconia suspension (40 volume per cent solid loading) with a viscosity value of 127 mPa·s was proposed. The optimal laser scanning speed for zirconia bridge fabrication was 1200 mm/s. A relative density of 98.58 per cent was achieved; the obtained surface Vickers hardness and surface roughness were 1,398 HV and 2.06 µm, respectively.
Originality/value
This paper provides a potential technical method for manufacturing complex zirconia dental bridges and other small complex-shaped ceramic components which are difficult to be made by other manufacturing techniques.
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Sutti Sooampon, Pagaporn Pantuwadee Pisarnturakit and Sireerat Sooampon
This study investigated the conditions required to foster healthcare innovation. Due to the limited research and development (R&D) capability of the Thai private sector…
Abstract
Purpose
This study investigated the conditions required to foster healthcare innovation. Due to the limited research and development (R&D) capability of the Thai private sector, universities are increasingly expected to be emerging sources of healthcare products. However, the lack of experience in research commercialization requires that whether and how Thai university researchers can serve this mission be explored.
Design/methodology/approach
A promising dental implant product development project was investigated using the single-case research methodology. In-depth interviews were conducted with three key members involved in this innovative project. Questions concerning how a team of university researchers could embark on and overcome the obstacles encountered during their entrepreneurial project were asked. Based on the conceptual foundation of academic entrepreneurship, primary and additional secondary data were analyzed to acquire knowledge of academic entrepreneurship in healthcare in an emerging economy.
Findings
Healthcare inequality has generated entrepreneurial initiatives by healthcare researchers to develop low-cost dental implants. However, their efforts have been insufficient to progress to the commercialization stage. An informal relationship among socially oriented partners, including interdisciplinary experts, not-for-profit-oriented manufacturers and early adopters contributed to this project's success.
Originality/value
To foster healthcare innovation, the authors’ micro-level evidence of a socially oriented partnership on an informal basis indicates the need for inter-professional governance that maintains a cross-organizational environment between healthcare researchers and external parties. The future contributions to innovation management by healthcare professionals should be enhanced. A socially entrepreneurial model of healthcare innovation is suggested for further consideration as an enabling policy option for inter-professional partnership in emerging economies.
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Rachela Levy, Bruce Rosen, Michael Wiener and Jonathan Mann
The behaviour of health care professionals is known to be influenced, in part, by their method of remuneration and the financial incentives they face. Describes how the Medical…
Abstract
The behaviour of health care professionals is known to be influenced, in part, by their method of remuneration and the financial incentives they face. Describes how the Medical Corps of the Israel Defence Forces (IDF) went about choosing a reimbursement method to increase incentives for dentists and decrease waiting time for the public. Based on a questionnaire sent to all 23 dentists working in a unique IDF civilian dental clinic, and on other information which was available on the productivity and income of these dentists, a new method of remuneration was suggested and accepted, by which a combined method of fee‐for‐service and salary will be introduced. The base hourly pay and per crown fee were set on levels which provide for a larger compensation range and increase the incentive for improved productivity levels. This suggested method will be investigated further and re‐evaluated one year after its implementation.
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Secil Ozkan Ata, Canan Akay and Nazim Ata
The purpose of this study was to investigate the effect of the environmental pressure changes on the bond strength between zirconia ceramics and adhesive resin cement.
Abstract
Purpose
The purpose of this study was to investigate the effect of the environmental pressure changes on the bond strength between zirconia ceramics and adhesive resin cement.
Design/methodology/approach
In total, 40 rectangular-shaped zirconium-oxide ceramic specimens were prepared. For surface modification, all zirconia specimens were sandblasted with 50 μm alumina particles. The composite resin discs were bonded to modified zirconia surfaces with resin cement. The specimens were divided into four groups; hyperbaric, hypobaric, hyperbaric + hypobaric and control group. The specimen underwent pressure cycles for 30 days. The shear bond strength test was performed by using the universal testing machine, and failures of the debonded samples were examined with scanning electron microscopy and light microscope.
Findings
No significant difference in bond strength was found between the hyperbaric, hypobaric and control groups after 30 days (p > 0.05). However, there was a significant difference in the hyperbaric + hypobaric group compared to the control group (p = 0.022). Also, the Weibull modulus was highest in control group and lowest in the hyperbaric + hypobaric group.
Originality/value
Barometric changes due to flying followed by diving may have an adverse effect on the retention of zirconia ceramics. Care should be taken in the selection of materials for dental treatment of people who are exposed to environmental pressure changes.
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