Types Of Trays Research Articles

Accuracy of polyether and vinylpolysiloxane impressions when using different types of 3D-printed impression trays - an in vitro study.

To investigate dimensional accuracy of polyether (PE) and vinylpolysiloxane (VPS) impressions taken with manually fabricated and 3D-printed trays. To evaluate impression accuracy, highly precise digital data of a metallic lower jaw model with prepared teeth (regions 34 and 36), an implant (region 47) and three precision balls placed occlusally along the dental arch served as reference. PE (Impregum, 3M Oral Care) and VPS (Aquasil, Dentsply Sirona) impressions (n = 10/group) were taken with trays fabricated using different materials and manufacturing techniques (FDM: filament deposition modeling, material: Arfona Tray, Arfona; printer: Pro2, Raise3D; DLP: digital light processing, material: V-Print Tray, VOCO, printer: Max, Asiga; MPR: manual processing with light-curing plates, material:LC Tray,Müller-Omicron) including an open implant impression. Scans of resulting stone models were compared with the reference situation. Global distance and angular deviations as well as local trueness and precision for abutment teeth and scan abutment were computed. Possible statistical effects were analyzed using ANOVA. Clinically acceptable global accuracy was found (all mean absolute distance changes < 100μm) and local accuracy for single abutments was excellent. All factors (abutment type, impression material, tray material) affected global accuracy (p < 0.05). In particular with PE impressions, MPR trays led to the best accuracies, both in horizontal and vertical direction. Within the limitations of this in vitro study, impression accuracy was high in use of both polyether and vinylpolysiloxane combined with different 3D-printed and customized trays making them recommendable for at least impressions for smaller fixed dental prostheses. Manually fabricated trays were overall still the best choice if utmost precision is required. Based on the results of this study, use of innovative CAD-CAM fabrication of individual impression trays fulfills the perquisites to be a viable option for impression making. In the sense of translational research, performance should be proved in a clinical setting.

Analysis of Corn Drying Rack Position on Tray Type Dryer on Drying Rate

This research aims to determine the drying characteristics of corn kernels using a tray-type dryer, including the moisture content of the corn kernels over time, the mass of the tested corn kernels over time and the drying rate over time. This research uses the experimental method. The drying process uses an incoming drying hot air temperature of 65ºC with an incoming hot drying air speed of 2 m/s, repeated three times until a water content of 14 ± 0.5% is reached. The dryer in this study used four stacking shelves counting from the bottom, which were filled with 500 grams per shelf. This research shows that the further the shelf is positioned from the incoming hot drying air, the lower the drying rate. Vice versa, the closer the drying Shelf is to the incoming hot air, the greater the drying rate. The average decrease in corn kernel mass was 0.95% for shelf 1, 0.93% for shelf 2, 0.90% for shelf 3 and 0.88% for shelf 4 during a drying period of 3.5 hours. The average decrease in water content was 4.4% for shelf 1, 4.29% for shelf 2, 4.15% for shelf 3 and 4% for shelf 4 during a drying period of 3.5 hours. The further the position of the shelf from the hot air dryer, the less air content contained in the material on the shelf can be absorbed by the hot air dryer and vice versa. The average drying rate was 16.8% for shelf 1, 15% for shelf 2, 13.6% for shelf 3 and 12.8% for shelf 4 during a drying period of 3.5 hours at a drying hot air temperature of 65oC with a drying air speed of 2 m/s. The research data analysis results showed that the hot air dryer should not be passed from below but rather from the side. This affects the drying process in the dryer and makes it evener.

Surgical instrument tray optimization process at a university hospital: A comprehensive overview

ObjectiveThis study presents the results of a surgical instrument tray optimization process implemented across all surgical specialties within the largest university hospital in Denmark. MethodsData was extracted from a comprehensive instrument optimization process including all Operating Rooms at Aarhus University Hospital. Adopting a holistic perspective, the optimization process, involved aligning instrument trays across various surgical specialties. This included: a) Reduction in number of instruments, b) Consolidation or separation of trays, c) Modularization - introducing modular trays for specific purposes, and d) Standardization - standardizing commonly used instruments across specialties. Instruments per tray, total number of instruments, and changes in the number of trays were compared against existing tray contents to identify discipline-specific changes. ResultsSome specialties made substantial alterations to tray structures, while others primarily reduced number of instruments in existing trays. Across all specialties, optimization resulted in 17 % decrease in number of tray types (p = 0.01, 95%CI:1.0–6.8), 1 % increase in total number of trays (p = 0.36, 95%CI:-11.9–4.8), 18 % decrease in number of instruments per tray (p = 0.0002, 95%CI: 3.2–7.6) and 16 % reduction in total number of instruments for all specialties (p < 0.0001, 95%CI:404–758). ConclusionThis study underscores complexity of instrument tray design. The approach employed at Aarhus University Hospital, involving interdisciplinary experts in an iterative design process, demonstrated the feasibility of redesigning instrument trays with significant reduction in content. Additionally, data suggests that reducing the number of instruments could lead to a decrease in workload within the Central Sterile Supply Specialty. This presents opportunity to minimize wasted resources and streamlining cleaning processes for unused instruments.

ЭФФЕКТИВНОСТЬ КОНТАКТНЫХ УСТРОЙСТВ ВАКУУМНЫХ КОЛОНН ДЛЯ ПЕРЕГОНКИ МАЗУТА

The article discusses various types of fractionanting tray for vacuum distillation. An example of a modern highly efficient fractionanting tray, giving a brief description of its operation

Evaluating the accuracy of one-piece and three-piece 3D-printed indirect bonding transfer trays: An in vitro study.

Recent developments in computer-aided design/computer-aided manufacturing (CAD/CAM) and 3D printing have enabled the fabrication of digital indirect bonding (IDB) transfer trays. These modern products require thorough investigation. The aim of the study was to determine the accuracy of one-piece and three-piece IDB transfer trays in vitro. An initial dental scan (IDS) of a randomly selected patient with digitally positioned brackets served as the master scan (MS) for designing 16 IDB transfer trays of each type. They were 3D printed and used for bonding 448 brackets to the models. Subsequently, the models were scanned with a TRIOS® 3 Intraoral Scanner (3Shape A/S, Copenhagen, Denmark), producing actual scans (ASs). The accuracy of bracket positioning was measured digitally on both MSs and ASs. The measurements were compared to the Objective Grading System for dental casts provided by the American Board of Orthodontics (ABO). The 2 types of IDB transfer trays showed comparable accuracy. All linear errors were within the clinically acceptable range, whereas the angular measurements demonstrated significant variability, resulting in clinically unacceptable transfer errors that ranged from 3.3% to 90.3%. The study results cannot be unconditionally extrapolated to other types of IDB transfer trays due to the diversity of their properties and features. The study evaluated the in vitro accuracy of IDB transfer trays. The revealed number of errors may be even higher in vivo due to limitations in visibility, salivary flow, interference from the tongue, and difficulties in achieving a proper fit of the IDB transfer tray to the teeth.

Evaluation of Implant Impression Accuracy Using Different Trays and Techniques with a 3D Superimposition Method.

To evaluate the dimensional accuracy of implant impressions obtained using five different tray types and two techniques. A partially dentate maxillary Kennedy Class II model was created as a reference model through 3D printing. Then, implant analogs 4.3 mm in diameter were placed at the first premolar, first molar, and second molar sites. Five types of trays were used to create impressions: (1) metal stock trays, (2) plastic stock trays, (3) custom trays fabricated using liquid crystal display (LCD), (4) custom trays fabricated using fused deposition modeling (FDM), and (5) custom trays fabricated using urethane dimethacrylate (UDMA) resin. Open and closed tray techniques were also compared. In total, 150 impressions were obtained. The reference model and impressions were scanned using a laboratory scanner. Additionally, the positional and angular deviations of implants with different tray types and techniques were evaluated using the superimposition method. There was no statistically significant difference (P > .05) between the impression accuracy with the different tray types and impression techniques. The angular deviations with plastic and UDMA trays were greater than those with metal, FDM, and LCD trays. Angular deviation at the second molar was greater when using closed plastic trays compared to open plastic trays. The highest and lowest positional deviations were observed at the first molar implant with an open plastic tray impression (mean ± SD of 62.46 ± 28.54 mm) and a closed LCD tray impression (36.59 ± 29.93 mm). The greatest angular deviation was observed with an open FDM tray impression at the first premolar implant (0.067 ± 0.024 degree), and the lowest angular deviation was observed with a closed metal stock tray impression at the second molar implant (0.039 ± 0.025 degree). Statistical differences were detected using the Mann-Whitney U test for paired groups and the Kruskal-Wallis test for groups with more than three comparisons (P > .05). Plastic and metal stock trays or conventional and 3D-printed custom trays can be used to obtain implant impressions for maxillary partially edentulous arches with similar dimensional accuracy. The five tray types and two techniques may be safely used to obtain impressions of partially edentulous maxillary arches with three implants.

Study on Impression Techniques and Materials for Implant among Dentists in Erbil city: A Survey study.

Background and Objectives: The Success and longevity of implant prosthesis is affected by an accurate fit which can be achieved through a proper impression technique and material, the techniques of impression taking can be made by either a closed or open tray impression procedures or by implant level impression technique. The main objective of the presented research was to investigate the most preferable impression material and technique for dental implant placement. Materials and methods: This research’s focus is on impression materials and the various impression techniques that can be used in implant restoration with a note on the recent advancements, with the help of a questionnaire given to dental professionals and postgraduate students who perform implants in Erbil City. Around 72 dentists were chosen, 24 of them were inside our teaching hospital, and 48 of them were chosen by random sampling. Results: The information gathered in this study sample group shows that the highest rate was for open tray technique about 54.2%, 37.5% responded closed tray and 8.3% responded abutment level. Regarding the most preferable material 75% responded for addition silicone, 23.6% responded for condensation silicone and 1.4% responded for alginate. According to most preferable type of tray 93.1% answered perforated stock tray and 6.9% answered special tray. 56.9% of the practitioners chose One step (heavy-light), 22.2% chose two step spaced putty wash, 13.9 % chose one step (monophase single viscosity) and 6.9% answered two-step unspaced putty wash. Conclusions: In conclusion open tray technique, stock tray, addition type of silicon and one-step (heavy-light) impression technique is the most preferable in this study. Keywords: Implant, Impression, open tray, closed tray, abutment, materials.

CLINICAL EVALUATION OF FIXED PARTIAL DENTURE IMPRESSION

Accurate impressions of teeth and the area to be restored are required in fixed Prosthodontics treatment for the laboratory to fabricate the desired restoration without any faults. The study aimed to raise awareness about the importance of improving individual skills to minimise impression errors, provide patients with high-quality prosthetics, and enhance their comfort. The study's objectives were to evaluate the clinically detectable errors in the impressions and to determine co-relations between possible risk factors that cause impression errors. This study follows a descriptive cross-sectional study design, which involves the probability convenience sampling technique, consisting of 150 impressions studied for the type of tray, type of material, type of technique, type of prosthesis ordered, arch of impression involved, size of tray, number of units prepared and retraction cord used. Impression errors were also assessed, including finish line errors, tears in the finish line, air bubbles, voids, and blood formed in the impression. Data were analysed with SPSS version 25.0, and correlations were found through a chi-square test. One hundred fifty impressions were analysed, with 80 being maxillary arch impressions. Most impressions utilised full arch trays (91.33%), with Monophase being the predominant technique (77%). Alginate emerged as the most commonly employed impression material (76%), and the most commonly used tray was the full arch tray (137). Crown preparations accounted for 70% of cases. Notably, retraction cord usage was observed in 58.7% of impressions. The study analysed 150 Impressions, finding 56.7% finish line errors, 21.3% tears, 19.3% bubbles, 80.7% voids, and 6% traces of blood. Our study reveals that material type, impression technique, no crown, arch of impression, prosthesis ordered, and retraction cord have a significant association (P &lt; 0.05) with the impression errors, except tray type having no significant association (P &gt; 0.05) with the impression errors. Based on the study's outcomes, this research identifies alginate and the monophase technique as prevalent choices among clinicians. The most common were voids and finish line errors, with tray selection showing no significant impact. The use of retraction cords notably reduces impression errors, indicating a strong association. Overall, crown impressions exhibit greater accuracy compared to bridge impressions.

Design and Experimentation of a Machine Vision-Based Cucumber Quality Grader.

The North China type cucumber, characterized by its dense spines and top flowers, is susceptible to damage during the grading process, affecting its market value. Moreover, traditional manual grading methods are time-consuming and labor-intensive. To address these issues, this paper proposes a cucumber quality grader based on machine vision and deep learning. In the electromechanical aspect, a novel fixed tray type grading mechanism is designed to prevent damage to the vulnerable North China type cucumbers during the grading process. In the vision grading algorithm, a new convolutional neural network is introduced named MassNet, capable of predicting cucumber mass using only a top-view image. After obtaining the cucumber mass prediction, mass grading is achieved. Experimental validation includes assessing the electromechanical performance of the grader, comparing MassNet with different models in predicting cucumber mass, and evaluating the online grading performance of the integrated algorithm. Experimental results indicate that the designed cucumber quality grader achieves a maximum capacity of 2.3 t/hr. In comparison with AlexNet, MobileNet, and ResNet, MassNet demonstrates superior cucumber mass prediction, with a MAPE of 3.9% and RMSE of 6.7 g. In online mass grading experiments, the grading efficiency of the cucumber quality grader reaches 93%.

Removal of chemicals from effluent using photobioreactor technology to improve environmental and health impacts

Abstract The treatment of industrial waste water using cyanobacteria in photobioreactor for the removal of sulphide, COD and phenol. The microorganisms were collected from the effluent treatment plant of a petroleum refinery and a biofilm was developed in nutrient medium. The reactor was fed with cyanobacteria. After biofilm formation and acclimatization, the same procedure was followed for 16 days in a rectangular tray type photo bioreactor for the treatment of industrial waste water. From continuous mode of operation, it was found that the phototrophic microorganisms can degrade the pollutants present in industrial waste water. The removal efficiency of hardness 75 %, sulphide 95.8 %, COD 98.7 %, phenol 99.9 % and nitrate 83.7 % was studied. The present works shows that it is feasible to use cyanobacteria in a photo bioreactor for the treatment of industrial waste water.

Eficiência do sistema floating na produção de mudas de alface utilizando diferentes bandejas e concentrações de solução nutritiva

ABSTRACT The quality of seedlings is a determining factor to guarantee the greatest potential crop productivity. The aim of this study was to evaluate the quality of lettuce seedlings grown in floating system, in relation to cell volume and electrical conductivity of the nutrient solution. The experiment was carried out in a completely randomized design, in a 3 x 2 x 4 factorial scheme, with three replicates. Seedlings of three lettuce cultivars (Great Lakes 659, Elba and Creta) were produced in two types of trays (128 and 200 cells) and fertigated with nutrient solutions (four electrical conductivities of 1.0; 1.5; 2.0 and 2.5 dS/m). The variables evaluated were: height, number of leaves, length of the main root, stem diameter, leaf area, total dry mass and shoot dry mass/roots dry mass (MSPA/MSR) ratio. Great Lakes 659 showed more vigorous seedlings for most of the evaluated variables. The three cultivars produced higher quality seedlings when cultivated in trays with 128 cells, with the EC of the nutrient solution ranging from 1.8 to 2.0 dS/m.

Assessment of the of fixed dental prosthesis impressions received at commercial dental laboratories in Aljabal-Alakhdar region, Libya0

Background: Crown and bridge prosthodontics needs an accurate and precise impression (positive replica) of the abutment teeth and the edentulous region to be rehabilitated for the dental technician to be able to construct the high quality and well adapted fixed dental restoration without mistakes. The aim of the current survey was to assess any visible mistakes commonly observed in fixed dental prosthesis impressions received at five commercial dental laboratories, frequency errors determination, and to determine any possible association between the preparation finish line errors and other assessed factors. Materials and methods: 150 fixed prosthodontic impressions were collected from five commercial dental laboratories located at Aljabal-Alakhdar region, Libya. All the fixed prosthodontic impressions which had been received by the visited commercial dental laboratories were assessed for many factors in relation to the accuracy such as the dental arch involved, prepared abutment teeth, dental impression materials used, and final techniques and viscosity of the impression, the type of impression tray, full-arch or segmental impression tray, the impression tray size, type of fixed dental restoration requested, mistakes in impression material or tray used, gingival tissue dilation errors, closed-mouth impression technique errors, and finish line errors. No attempts were made to determine the reason of the detected errors in each fixed prosthodontic impression assessed. Association between dental practitioner years of experience and gender and impression errors was evaluated. The association between categorical variables and the outcomes were examined by the use of Chi square and Fisher exact tests. Results: Condensation silicone was the most impression material used. Of the impressions evaluated 121(80.6%), 97% have at least one detectable error, 103(68.6%) had finish line errors, 53.9% had tooth preparation area errors. Visible contamination of impression with blood was seen in about 79(52.2%) of the assessed impressions. There was significant association between the type of dental impression material and errors in the preparation cervical finish line and tooth preparation area. Conclusion: In the present study, it has been found that a high frequency of recognizable errors was detected in crown and bridge impressions received by the five commercial dental laboratories. This can result in poorly fitted fixed restorations cemented for the fixed prosthodontic patients.

Comparison of the accuracy of two techniques for three-dimensional digital indirect bonding of orthodontic brackets: A randomized controlled trial.

This study aimed to clinically compare the accuracy of bracket positioning between three-dimensionally (3D) printed indirect bonding trays and vacuum-formed trays made over 3D-printed models. Fourteen patients, planned for fixed orthodontic therapy, were randomly divided into two equal groups. For both groups, both dental arches were scanned, to acquire virtual models, brackets were virtually positioned from central incisors to second premolars, and scans for the final bracket positions were performed. In the first group, transfer trays were 3D-printed. In the second group, virtual models were 3D-printed, and vacuum-formed soft sheets were thermoformed on the printed model. Teeth were indirectly bonded and then scanned. Superimposition of the virtual and the final bracket positioning scans was performed to measure linear and angular deviations in brackets positions. The first group showed significantly less occlusogingival and buccolingual linear errors than the second group. No significant differences in angular deviations were found between both groups. The frequencies of clinically acceptable linear errors within 0.5 mm and angular errors within 2° showed no statistically significant difference between both groups (p> 0.05 for all measurements). The transfer errors in both groups showed linear directional biases toward the mesial, gingival and labial directions. There was no statistically significant difference in the rate of immediate debonding between both groups (10.7% and 7.1% for the first and the second groups, respectively, p=0.295). 3D-printed indirect bonding trays were more accurate than vacuum-formed trays, in terms of linear deviations. Both types of trays showed similar angular control.

Chairside 3-D printed impression trays: a new approach to increase the accuracy of conventional implant impression taking? An in vitro study

PurposeA high transfer accuracy of the intraoral implant position to a model is required, to manufacture implant-supported restorations. However, clinically relevant deviations persist between the intraoral implant position and the model obtained, even for the benchmark conventional custom implant impressions with polyether. Thus, new approaches using 3-D printed impression trays may increase the transfer accuracy of implant impressions. The ability to adjust parameters such as the thickness of the layers and the influence of the openings in the impression tray could potentially affect accuracy.MethodsFour different types of impression trays (n = 10 for each group) for the conventional impression technique were investigated: conventional custom impression tray, customized foil tray, chairside 3-D printed impression tray with the SHERA system, and the Primeprint system using an implant master model with four implants in the posterior region and a reference cube. After plaster model casting, all models were measured using a coordinate measuring machine, and the deviation from the reference dataset was determined. A statistical ANOVA analysis was performed (p < 0.05).ResultsChairside 3-D printed impression trays showed the best results, followed by conventional custom impression trays. Implant impressions obtained using a customized foil tray exhibited the lowest accuracy. Statistically significant differences were observed between 3-D printed impression trays and conventional custom impression and customized foil trays (p < 0.05). Whereas, the implant position did not have any significant influence on accuracy (p > 0.05).ConclusionsChairside 3-D printed impression trays significantly increase the transfer accuracy for implant impression taking.Graphical

Automating Seedling Counts in Horticulture Using Computer Vision and AI

The accelerated growth of computer vision techniques (CVT) has allowed their application in various disciplines, including horticulture, facilitating the work of producers, reducing costs, and improving quality of life. These techniques have made it possible to contribute to the automation of agro-industrial processes, avoiding excessive visual fatigue when undertaking repetitive tasks, such as monitoring and selecting seedlings grown in trays. In this study, an object detection model and a mobile application were developed that allowed seedlings to be counted from images and the calculation of the number of seedlings per tray. This system was developed under a CRISP-DM methodology to improve the capture of information, data processing, and the training of object detection models using data from six crops and four types of trays. Subsequently, an experimental test was carried out to verify the integration of both parts as a unified system, reaching an efficiency between 57% and 96% in the counting process.

Addition Silicone Impressions in Fixed Prosthodontics: Clinical Standpoints.

Addition silicones have revolutionized the field of fixed prosthodontics because of their dimensional stability, sufficient tear strengthand excellent detail reproduction. This review study aims to provide a detailed description of the essential variables to be taken into account during the process of making addition silicone impressions in fixed prosthodontics. These variables include the selection of appropriate tray type, size, and fabrication; the use of tray adhesive; gingival displacement techniques; manipulation of the impression material; the choice of the impression material's viscosity; impression techniques; and the proper insertion, removal, disinfection, and pouring of the cast. Additionally, this review aims to help doctors produce high-quality impressions by empowering them to critically assess the impressions to spot mistakes and motivating them to redo impressions that have serious problems before submitting them to the laboratory.

Characteristics of push valve centrifugal tray; a novel tray with pipe type downcomer

ABSTRACT The intention of providing this paper is to conduct an experimental investigation into the hydrodynamics of the push valve centrifugal tray, which has a new configuration, in order to retrofit the purpose of a stripper oil sweeting of Lavan oil manufacture. Experiments were performed on the commercial scale column by an air-water simulator rig. Two different pilot plants with 1.2 m and 3 m diameter have been used for experiments. Dry pressure drop, total pressure drop, and weeping data are presented on the commercial scale 1.2 m diameter column. The results compared with a sieve tray. Some correlations for the pressure drop and the weeping are presented. A pilot plant with a large diameter, 3 m, was also installed to predict the pressure drop with the exact characterization as the stripper column of Lavan oil manufacture to predict its pressure drop. The experiments were carried out in two different outlet weir heights, 0, 3 cm, and 2- and 4%-holes areas at various operating conditions. This article also introduced a new downcomer and tray design of the centrifugal tray. Experiments and industrial reports of this type of centrifugal tray show that it can be used in revamping and retrofit projects.

Optimizing the Functional Properties of Starch-Based Biodegradable Films.

A definitive screening design was used in order to evaluate the effects of starch, glycerol and montmorillonite (MMT) concentrations, as well as the drying temperature, drying tray type and starch species, on packaging film's functional properties. Optimization showed that in order to obtain films with the minimum possible thickness, the maximum elongation at break, the maximum tensile strength, as well as reduced water vapor permeability and low opacity, a combination of factors should be used as follows: 5.5% wt starch concentration, 30% wt glycerol concentration on a dry starch basis, 10.5% wt MMT concentration on a dry starch basis, 45 °C drying temperature, chickpea as the starch species and plexiglass as the drying tray type. Based on these results, starch films were prepared, and fresh minced meat was stored in them for 3 days. It was shown that the incorporation of MMT at 10.5% wt on a dry starch basis in the packaging films led to a decreased mesophilic and psychrotrophic bacteria growth factor compared to commercial packaging. When assessed for their biodegradability, the starch films disintegrated after 10 days of thermophilic incubation under simulated composting conditions. Finally, to prove their handling capability during industrial production, the starch films were rewound in a paper cylinder using an industrial-scale rewinding machine.

Seismic fragility analysis of suspended cable trays in civil buildings

The cable tray is a kind of non-structural component used to distribute the electric cable, which plays a vital role in maintaining the function of the building. Post-earthquake investigations proved that the collapse of the cable tray led to the loss of human life and business continuity. This study aims to understand the seismic fragility of typical suspended cable trays in civil buildings through full-scale shaking table tests and numerical simulation. Based on the shaking table test results, the damage states of the cable tray are defined. The finite element model for cable tray is established and verified by test results. The seismic fragility analysis of the cable tray is carried out by the incremental dynamic analysis method. The peak floor acceleration and the spectral acceleration are taken as intensity measures of seismic motions. The calculation results show that the peak floor acceleration is more suitable to be an intensity measure for the seismic fragility analysis of the cable tray. Seismic fragility curves of two typical types of cable trays are generated.

Effect of the baking tray type on colour and sensory characteristics of horse-gram supplemented biscuits

Effect of the baking tray type on colour and sensory characteristics of horse-gram supplemented biscuits