DIGITAL FABRICATION OF COMPLETE DENTURES, COMPARED TO CONVENTIONAL METHODS, MAY OFFER A MORE COST-EFFECTIVE APPROACH WITH IMPROVED PATIENT OUTCOMES.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Digitally versus conventionally fabricated complete dentures: A systematic review on cost-efficiency analysis and patient-reported outcome measures (PROMs). Tew, In Meei, Suet Yeo Soo, and Edmond Ho Nang Pow.The Journal of Prosthetic Dentistry (2023). SOURCE OF FUNDING: No fund was received. TYPE OF STUDY/DESIGN: Systematic review.

[Evaluation of production and clinical working time of computer-aided design/computer-aided manufacturing (CAD/CAM) custom trays for complete denture].

OBJECTIVE: To compare the technician fabrication time and clinical working time of custom trays fabricated using two different methods, the three-dimensional printing custom trays and the conventional custom trays, and to prove the feasibility of the computer-aided design/computer-aided manufacturing (CAD/CAM) custom trays in clinical use from the perspective of clinical time cost. METHODS: Twenty edentulous patients were recruited into this study, which was prospective, single blind, randomized self-control clinical trials. Two custom trays were fabricated for each participant. One of the custom trays was fabricated using functional suitable denture (FSD) system through CAD/CAM process, and the other was manually fabricated using conventional methods. Then the final impressions were taken using both the custom trays, followed by utilizing the final impression to fabricate complete dentures respectively. The technician production time of the custom trays and the clinical working time of taking the final impression was recorded. RESULTS: The average time spent on fabricating the three-dimensional printing custom trays using FSD system and fabricating the conventional custom trays manually were (28.6±2.9) min and (31.1±5.7) min, respectively. The average time spent on making the final impression with the three-dimensional printing custom trays using FSD system and the conventional custom trays fabricated manually were (23.4±11.5) min and (25.4±13.0) min, respectively. There was significant difference in the technician fabrication time and the clinical working time between the three-dimensional printing custom trays using FSD system and the conventional custom trays fabricated manually (P<0.05). CONCLUSION: The average time spent on fabricating three-dimensional printing custom trays using FSD system and making the final impression with the trays are less than those of the conventional custom trays fabricated manually, which reveals that the FSD three-dimensional printing custom trays is less time-consuming both in the clinical and laboratory process than the conventional custom trays. In addition, when we manufacture custom trays by three-dimensional printing method, there is no need to pour preliminary cast after taking the primary impression, therefore, it can save the impression material and model material. As to completing denture restoration, manufacturing custom trays using FSD system is worth being popularized.

Faster Algorithms for Isomer Network Generation.

Isomer networks provide a mechanism to understand and interpret relationships between organic molecules with applications in medicinal chemistry and drug design. The extraction of isomer networks is a time- and data-intensive computation (e.g., we have experimentally determined the space required for the computation of a set of 25 isomers of nicotine to be 205 MB; extrapolating this, we have projected the computation to require 8 TB of storage for a set of 1 050 219 isomers of nicotine). In this paper we describe our efforts to improve the network extraction process by using the symmetry present in most molecules to reduce runtime and memory and streamlining the algorithm used for the detection of duplicate dnNames. Together, these techniques result in reductions in memory of up to 60% and improvements in runtime of up to a factor of 100.

1001 Ways to run AutoDock Vina for virtual screening.

Large-scale computing technologies have enabled high-throughput virtual screening involving thousands to millions of drug candidates. It is not trivial, however, for biochemical scientists to evaluate the technical alternatives and their implications for running such large experiments. Besides experience with the molecular docking tool itself, the scientist needs to learn how to run it on high-performance computing (HPC) infrastructures, and understand the impact of the choices made. Here, we review such considerations for a specific tool, AutoDock Vina, and use experimental data to illustrate the following points: (1) an additional level of parallelization increases virtual screening throughput on a multi-core machine; (2) capturing of the random seed is not enough (though necessary) for reproducibility on heterogeneous distributed computing systems; (3) the overall time spent on the screening of a ligand library can be improved by analysis of factors affecting execution time per ligand, including number of active torsions, heavy atoms and exhaustiveness. We also illustrate differences among four common HPC infrastructures: grid, Hadoop, small cluster and multi-core (virtual machine on the cloud). Our analysis shows that these platforms are suitable for screening experiments of different sizes. These considerations can guide scientists when choosing the best computing platform and set-up for their future large virtual screening experiments.

Understanding dental CAD/CAM for restorations--dental milling machines from a mechanical engineering viewpoint. Part B: labside milling machines.

Nowadays, dental numerical controlled (NC) milling machines are available for dental laboratories (labside solution) and dental production centers. This article provides a mechanical engineering approach to NC milling machines to help dental technicians understand the involvement of technology in digital dentistry practice. The technical and economic criteria are described for four labside and two production center dental NC milling machines available on the market. The technical criteria are focused on the capacities of the embedded technologies of milling machines to mill prosthetic materials and various restoration shapes. The economic criteria are focused on investment cost and interoperability with third-party software. The clinical relevance of the technology is discussed through the accuracy and integrity of the restoration. It can be asserted that dental production center milling machines offer a wider range of materials and types of restoration shapes than labside solutions, while labside solutions offer a wider range than chairside solutions. The accuracy and integrity of restorations may be improved as a function of the embedded technologies provided. However, the more complex the technical solutions available, the more skilled the user must be. Investment cost and interoperability with third-party software increase according to the quality of the embedded technologies implemented. Each private dental practice may decide which fabrication option to use depending on the scope of the practice.

Understanding dental CAD/CAM for restorations - dental milling machines from a mechanical engineering viewpoint. Part A: chairside milling machines.

The dental milling machine is an important device in the dental CAD/CAM chain. Nowadays, dental numerical controlled (NC) milling machines are available for dental surgeries (chairside solution). This article provides a mechanical engineering approach to NC milling machines to help dentists understand the involvement of technology in digital dentistry practice. First, some technical concepts and definitions associated with NC milling machines are described from a mechanical engineering viewpoint. The technical and economic criteria of four chairside dental NC milling machines that are available on the market are then described. The technical criteria are focused on the capacities of the embedded technologies of these milling machines to mill both prosthetic materials and types of shape restorations. The economic criteria are focused on investment costs and interoperability with third-party software. The clinical relevance of the technology is assessed in terms of the accuracy and integrity of the restoration.

Digital vs. conventional implant prosthetic workflows: a cost/time analysis.

OBJECTIVES: The aim of this prospective cohort trial was to perform a cost/time analysis for implant-supported single-unit reconstructions in the digital workflow compared to the conventional pathway. MATERIALS AND METHODS: A total of 20 patients were included for rehabilitation with 2 × 20 implant crowns in a crossover study design and treated consecutively each with customized titanium abutments plus CAD/CAM-zirconia-suprastructures (test: digital) and with standardized titanium abutments plus PFM-crowns (control conventional). Starting with prosthetic treatment, analysis was estimated for clinical and laboratory work steps including measure of costs in Swiss Francs (CHF), productivity rates and cost minimization for first-line therapy. Statistical calculations were performed with Wilcoxon signed-rank test. RESULTS: Both protocols worked successfully for all test and control reconstructions. Direct treatment costs were significantly lower for the digital workflow 1815.35 CHF compared to the conventional pathway 2119.65 CHF [P = 0.0004]. For subprocess evaluation, total laboratory costs were calculated as 941.95 CHF for the test group and 1245.65 CHF for the control group, respectively [P = 0.003]. The clinical dental productivity rate amounted to 29.64 CHF/min (digital) and 24.37 CHF/min (conventional) [P = 0.002]. Overall, cost minimization analysis exhibited an 18% cost reduction within the digital process. CONCLUSION: The digital workflow was more efficient than the established conventional pathway for implant-supported crowns in this investigation.

Acetate templating on digital images is more accurate than computer-based templating for total hip arthroplasty.

BACKGROUND: Templating is an important aspect of preoperative planning for total hip arthroplasty and can help determine the size and positioning of the prosthesis. Historically, templating has been performed using acetate templates over printed radiographs. As a result of the increasing use of digital imaging, surgeons now either obtain additional printed radiographs solely for templating purposes or use specialized digital templating software, both of which carry additional cost. QUESTIONS/PURPOSES: The purposes of this study was to compare acetate templating of digitally calibrated images on an LCD monitor to digital templating in terms of (1) accuracy; (2) reproducibility; and (3) time efficiency. METHODS: Acetate onlay templating was performed directly over digital radiographs on an LCD monitor and was compared with digital templating. Five separate observers participated in this study templating on 52 total hip arthroplasties. For the acetate templating, the digital images were magnified to the scaled reference on the templates provided by the manufacturer (ratio 1.2:1) before templating using a 25-mm marker as a reference. Both the acetate and digital templating results were then compared with the actual implanted components to determine accuracy. Interobserver and intraobserver variability was determined by an intraclass correlation coefficient. Observers recorded time to complete templating from the time of complete upload of patients' imaging onto the system to completion of templating. RESULTS: Both acetate and digital templates demonstrated moderate accuracy in predicting within one size of the eventual implanted acetabular cup (77% [199 of 260]; 70% [181 of 260], respectively; p = 0.050; 95% confidence interval [CI], 0.058-0.32), whereas acetate templating was better at predicting the femoral stem compared to digital templating (75% [195 of 260]; 60% [155 of 260], respectively; p < 0.001; 95% CI, 0.084-0.32). Acetate templating showed moderate to substantial interobserver agreement (cup intraclass correlation coefficient [ICC] = 0.55; 95% CI, 0.14-0.86; femoral ICC = 0.75; 95% CI, 0.39-0.95) and both methods showed almost perfect intraobserver agreement in reproducibility (acetate cup ICC = 0.82; 95% CI, 0.66-0.97; acetate femoral ICC = 0.86; 95% CI, 0.74-0.97; digital cup ICC = 0.82; 95% CI, 0.68-0.97; digital femoral ICC = 0.88; 95% CI, 0.77-1.0). Acetate templating could be performed more quickly (acetate mean 119 seconds; range, 37-220 seconds versus 154 seconds; range, 73-343 seconds; p < 0.001). CONCLUSIONS: Acetate onlay templating on digitally calibrated images can be a reliable substitute for digital templating using specialized software. It is quicker to perform and much less expensive. Hospitals and practices need not purchase expensive software, particularly at lower volume centers. LEVEL OF EVIDENCE: Level III, diagnostic study.

Digital casts in orthodontics: a comparison of 4 software systems.

INTRODUCTION: The introduction of digital cast models is inevitable in the otherwise digitized everyday life of orthodontics. The introduction of this new technology, however, is not straightforward, and selecting an appropriate system can be difficult. The aim of the study was to compare 4 orthodontic digital software systems regarding service, features, and usability. METHODS: Information regarding service offered by the companies was obtained from questionnaires and Web sites. The features of each software system were collected by exploring the user manuals and the software programs. Replicas of pretreatment casts were sent to Cadent (OrthoCAD; Cadent, Carlstadt, NJ), OthoLab (O3DM; OrthoLab, Poznan, Poland), OrthoProof (DigiModel; OrthoProof, Nieuwegein, The Netherlands), and 3Shape (OrthoAnalyzer; 3Shape, Copenhagen, Denmark). The usability of the programs was assessed by experts in interaction design and usability using the "enhanced cognitive walkthrough" method: 4 tasks were defined and performed by a group of domain experts while they were observed by usability experts. RESULTS: The services provided by the companies were similar. Regarding the features, all 4 systems were able to perform basic measurements; however, not all provided the peer assessment rating index or the American Board of Orthodontics analysis, simulation of the treatment with braces, or digital articulation of the casts. All systems demonstrated weaknesses in usability. However, OrthoCAD and 03DM were considered to be easier to learn for first-time users. CONCLUSIONS: In general, the usability of these programs was poor and needs to be further developed. Hands-on training supervised by the program experts is recommended for beginners.

ABC model for cost estimation of custom implants by Additive Manufacturing.

Computer-aided design (CAD) models can now be directly converted into products and structures. One technique to realize such approach is through Additive Manufacturing (AM). AM is relatively new manufacturing technology in which products are manufactured by layering various materials like rubber, metal, ceramic, composites, and polymers. However, the use of this technology requires consideration of its associated cost to ensure its competitiveness. In this paper, a simplified mathematical cost model is suggested. The model considers the main components of costs. The model formula utilizes expenses related to the pre-processing, main processing, and the post-processing operations. To validate the model, it is tested to estimate the cost of medical implants manufacturing using AM technique. In many cases, medical implants require unique or dedicated design for each patient. Hence cost estimation will help to assess and estimate the required financial resources for such operations. A case study is provided in this paper to estimate the manufacturing cost of a finger's phalanges bone, with metal implant using AM technique. The developed model may be described as Activity Based Costing (ABC). The model is introduced to estimate the cost of parts produced using AM technique. Although the model is developed to suit custom implant manufacturing using AM technique, its use may also be adapted to suit the manufacturing of many other parts and products. The developed model is aiming to achieve several tasks namely assigning cost drivers to each activity, estimating the cost of individual actions, allocating overhead expenses, calculating the overall production cost, and establishing an acceptable selling price. It assists companies in computing the cost of custom implants for customers, enhancing the accuracy of production cost estimates, and ultimately boosting profitability.

Has the Picture Archiving and Communication System (PACS) become a commodity?

The Picture Archiving and Communication System (PACS) market has been transformed by disruptive innovations from the information technology industry. The cost of storage alone has dropped by a factor of 100 within the past 10 years. Improvements in display, processing, and networking have likewise enabled PACS to be a capable replacement for film. The maturity of PACS has permeated the US healthcare industry from large academic hospitals to small outpatient imaging centers. Can PACS continue to be a platform for innovation or has it become a commodity?

Fibula Jaw-in-a-Day with Minimal Computer-Aided Design and Manufacturing: Maximizing Efficiency, Cost-Effectiveness, Intraoperative Flexibility, and Quality.

SUMMARY: The vascularized fibular flap has been the mainstay for mandibular reconstruction for over 30 years. Its latest evolutionary step is the jaw-in-a-day operation, during which the fibula flap and dental prosthesis restoration are performed in a single stage. Computer-aided design and manufacturing technology in mandibular reconstruction has gained popularity, as it simplifies the procedure and produces excellent outcomes. However, it is costly, time-consuming, and limited in cases that involve complex defects, including bone and soft-tissue coverage. Moreover, it does not allow for intraoperative changes in the surgical plan, including defect size and recipient vessel selection.The authors describe their approach, including a conventional technique for fibula osteoseptocutaneous flap harvest without the need for a premanufactured cutting guide, using bundled wooden tongue spatulas instead, a stereolithographic model to customize commercially ready-made reconstruction plates, and two pieces of resin to maintain occlusive alignment of the remaining jaw segments during mandibular osteotomy. Dental implants are inserted free-hand. Vector guides are then connected to the implants following insertion into the fibula to confirm acceptable alignment and subsequently replaced with scan sensors. An intraoperative digital scan is used to design and to produce a dental prosthesis by in-house milling of a polymethylmethacrylate block. From our 10-case experience over the past 3 years, we have found that our approach offers a reliable method that matches the excellent outcomes seen using full computer-assisted design and manufacturing technology. It is time- and cost-effective, not limited to relatively simple jaw defects, and can readily accommodate intraoperative changes of surgical plan.

Implementation strategies for incorporating new technologies into the dental practice.

Staying ahead of the technology curve is an ongoing challenge for all dentists. Ignoring advancements in technology and the related improvements in diagnostics and delivery of care, as well as the impact technology may have on productivity in practice, is simply not an option for the modern clinician who aims to maintain a successful contemporary practice. This article delivers some insight into the challenges that arise when upgrades in technology and the related acquisition investment are considered.

The design of tourism product CAD three-dimensional modeling system using VR technology.

In view of the high homogeneity of tourism products all over the country, an attempt is made to design virtual visit tourism products with cultural experience background, which can reflect the characteristics of culture + tourism in different scenic spots, so that tourists can deeply experience the local culture. Combined with computer aided design (CAD), the virtual three-dimensional (3D) modeling system of scenic spots is designed, and VR real scene visit interactive tourism products suitable for different scenic spots are designed. 360° VR panoramic display technology is used for 360° VR panoramic video shooting and visiting system display production of Elephant Trunk Hill park scenery. A total of 157 images are collected and 720 cloud panoramic interactive H5 tool is selected to produce a display system suitable for 360° VR panoramic display of scenic spots. Meanwhile, based on single view RGB-D image, the latest convolutional neural network (CNN) algorithm and point cloud processing algorithm are used to design the indoor 3D scene reconstruction algorithm based on semantic understanding. Experiments show that the pixel accuracy and mean intersection over union of the indoor scene layout segmentation network segmentation results are 89.5% and 60.9%, respectively, that is, it has high accuracy. The VR real scene visit interactive tourism product can make tourists have a more immersive sense of interaction and experience before, during and after the tour.

An advanced prosthetic manufacturing framework for economic personalised ear prostheses.

Craniofacial prostheses are commonly used to restore aesthetics for those suffering from malformed, damaged, or missing tissue. Traditional fabrication is costly, uncomfortable for the patient, and laborious; involving several hours of hand-crafting by a prosthetist, with the results highly dependent on their skill level. In this paper, we present an advanced manufacturing framework employing three-dimensional scanning, computer-aided design, and computer-aided manufacturing to efficiently fabricate patient-specific ear prostheses. Three-dimensional scans were taken of ears of six participants using a structured light scanner. These were processed using software to model the prostheses and 3-part negative moulds, which were fabricated on a low-cost desktop 3D printer, and cast with silicone to produce ear prostheses. The average cost was approximately $3 for consumables and $116 for 2 h of labour. An injection method with smoothed 3D printed ABS moulds was also developed at a cost of approximately $155 for consumables and labour. This contrasts with traditional hand-crafted prostheses which range from $2,000 to $7,000 and take around 14 to 15 h of labour. This advanced manufacturing framework provides potential for non-invasive, low cost, and high-accuracy alternative to current techniques, is easily translatable to other prostheses, and has potential for further cost reduction.

A method for the easy fabrication of all-ceramic bridges with the Cerec system.

Both pressing technology and CAD/CAM methods have proven themselves clinically for the fabrication of all-ceramic restorations. The advantages of the Cerec technology for the economic fabrication of all-ceramic bridges can be exploited by the use of burn-out blanks of polymer material. The milling process of very hard ceramics in the milling unit, which has some disadvantages, is replaced by the pressing process and makes the IPS e.max press material accessible to CAD/CAM users, primarily for extending the range of indications to splinted crowns and small all-ceramic bridges.

Chest tube simulator: development of low-cost model for training of physicians and medical students. / Simulador de dreno de tórax: desenvolvimento de modelo de baixo custo para capacitação de médicos e estudantes de medicina.

OBJECTIVE: by using a 3D printer, to create a low-cost human chest cavity simulator that allows the reproduction of the closed chest drainage technique (CCD), comparing its effectiveness with that of the animal model. METHODS: it was made a 3D printing of the bony framework of a human thorax from a chest computerized tomography scan. After printing the ribs, we performed tests with several materials that contributed to form the simulation of the thoracic cavity and pleura. An experimental, randomized, and controlled study, comparing the efficacy of the simulator to the efficacy of the animal model, was then carried out in the teaching of CCD technique for medical students, who were divided into two groups: animal model group and simulator model group, that trained CCD technique in animals and in the simulator model, respectively. RESULTS: the chest reconstruction required anatomical knowledge for tomography analysis and for faithful 3D surface editing. There was no significant difference in the safety of performing the procedure in both groups (7.61 vs. 7.73; p=0.398). A higher score was observed in the simulator model group for "use as didactic material" and "learning of the chest drainage technique", when compared to the animal model group (p<0.05). CONCLUSION: the final cost for producing the model was lower than that of a commercial simulator, what demonstrates the feasibility of using 3D printing for this purpose. In addition, the developed simulator was shown to be equivalent to the animal model in relation to the simulation of the drainage technique for practical learning, and there was preference for the simulator model as didactic material.

OBJETIVO: criar, em impressora 3D, um simulador de baixo custo de caixa torácica humana que permita a reprodução da técnica de drenagem fechada de tórax (DFT) comparando sua eficácia com a do modelo animal. MÉTODOS: foi realizada impressão 3D do arcabouço ósseo de um tórax humano a partir de uma tomografia de tórax. Após a impressão das costelas, foram realizados testes com diversos materiais que contribuíram para formar a simulação da caixa torácica e da pleura. Foi, então, realizado um estudo experimental, randomizado e controlado comparando sua eficácia ao modelo animal no ensino da DFT para estudantes de medicina, que foram divididos em dois grupos: Grupo Modelo Animal e Grupo Modelo Simulador, que treinaram DFT em animais e no modelo simulador, respectivamente. RESULTADOS: a reconstrução do tórax exigiu o conhecimento anatômico para análise da tomografia e para edição fiel da superfície 3D. Não houve diferença significativa quanto à segurança de realizar o procedimento entre os grupos (7,61 vs. 7,73; p=0,398). Foi observada maior pontuação no grupo modelo simulador para uso como material didático e aprendizado da técnica de drenagem torácica quando comparado ao grupo modelo animal (p<0,05). CONCLUSÃO: o custo final para a confecção do modelo foi inferior ao de um simulador comercial, o que demonstra a viabilidade do uso da impressão 3D para esse fim. Além disso, o simulador desenvolvido se mostrou equivalente ao modelo animal quanto à simulação da técnica de drenagem para aprendizado prático e houve preferência pelo modelo simulador como material didático.