Cast Models Research Articles

The Impact of Early Orthodontic Intervention on Dental and Skeletal Development in Children with Mixed Dentition.

The mixed dentition stage in children is a critical period for orthodontic assessment and intervention. This study investigates the effects of interceptive orthodontics on dental and skeletal development in children with mixed dentition, aiming to evaluate the potential benefits of early orthodontic treatment. A retrospective analysis was conducted on a cohort of 150 children with mixed dentition (aged 7-11 years), who received interceptive orthodontic treatment. Dental and skeletal records, including cephalometric radiographs and dental cast models, were collected before and after treatment. A control group of 150 untreated children with mixed dentition was also assessed for comparison. Various dental and skeletal parameters, such as dental alignment, overjet (OJ), overbite (OB), and cephalometric measurements, were recorded and analyzed. The results of this study indicate significant improvements in dental alignment and occlusion in the group of children who received interceptive orthodontic treatment. The average reduction in OJ was 3.5 mm, and the OB correction averaged 2.1 mm. Cephalometric analysis showed positive changes in skeletal relationships, with a mean reduction in the angle formed by point A, nasion (N) and point B. (ANB) angle of 2.8 degrees. These improvements were statistically significant compared to the control group (P < 0.05). Early orthodontic intervention, such as interceptive orthodontics, has a positive impact on dental and skeletal development in children with mixed dentition.

Novel Technique of Interproximal Enamel Reduction Based on Computer-Aided Navigation Technique-An In Vitro Study.

The aim of this study was to analyze and compare the accuracy of a novel interproximal enamel reduction (IPR) technique based on a computer-aided static navigation technique with respect to a conventional free-hand-based technique for interproximal enamel reduction. Twenty anatomical-based experimental cast models of polyurethane were randomly distributed into the following IPR techniques: IPR technique based on computer-aided static navigation technique (n = 10) (GI) for Group A and conventional free-hand-based technique for the IPR (n = 10) (FHT) for Group B. The anatomical-based experimental cast models of polyurethane randomly assigned to the GI study group were submitted for a preoperative 3D intraoral surface scan; then, datasets were uploaded into 3D implant-planning software to design virtual templates for the interproximal enamel reduction technique. Afterward, the anatomical-based experimental cast models of polyurethane of both GI and FHT study groups were subjected to a postoperative digital impression by a 3D intraoral surface scan to compare the accuracy of the interproximal enamel reduction techniques at the buccal (mm), lingual/palatal (mm), and angular (◦) levels using the Student t-test. Statistically significant differences between the interproximal enamel reduction technique based on the computer-aided static navigation technique and the conventional free-hand-based technique for the interproximal enamel reduction at the buccal (p = 0.0008) and lingual/palatal (p < 0.0001) levels; however, no statistically significant differences were shown at the angular level (p = 0.1042). The interproximal enamel reduction technique based on computer-aided static navigation technique was more accurate than the conventional free-hand-based technique for interproximal enamel reduction.

The value of imbibition and syneresis for dental impression on red seaweed: a laboratory experiment

ABSTRACT Introduction: Alginate is a type of elastic dental impression, which is an irreversible hydrocolloid. The main components in sodium alginate can be obtained naturally through the extraction process from seaweed (Kappaphycus alvarezii). Several physical characteristics must be fulfilled by dental impressions, such as dimensional stability related to imbibition and syneresis. ANSI/ADA specification No.18 regarding the maximum permitted change in alginate impression materials may not exceed 0.5%. This research aimed to analyze the value of imbibition and syneresis on dental impressions of red seaweed extract (K.alvarezii). Methods: The research was conducted using an experimental laboratory method with a post-test-only control group design. There were two groups, namely the control group of commercial dental impressions and the treatment group using dental impressions with the sodium alginate extracted from red seaweed (K.Alvarezii) by the acid method, and the FTIR test was performed to analyze compound sodium alginate. Imbibition and syneresis measurements were carried out using a calliper on a plaster cast model from negative mould casting results, where previously, the mould was soaked in water for imbibition and evaporated for syneresis. Results: Imbibition and syneresis tests showed that the impression material group with sodium alginate from red algae was significantly lower than those with commercial impression materials. It was concluded that the impression material with sodium alginate from red seaweed had an effect on reducing the percentage of syneresis (p≤0.05) and imbibition (p≤0.05) of the impression material. Based on the results of our research, it was found that the alginate impression material extracted from red seaweed (k.alvarezii) had an imbibition value of 0.33% (p≤0.05) and syneresis of 0.28%, (p≤0.05) lower compared to alginate impression materials. commercial alginate impression material. Conclusion: The imbibition and syneresis values of red seaweed alginate show an excessively low value compared to commercial alginates. KEYWORDS dental impression,sodium alginate, Kappaphycus alvarezii, imbibition, syneresis

Comparative Analysis of Tooth Measurements on Conventional and Digital Study Model – Validity Reliability Study

Abstract Aim: The aim of the study was to assess the accuracy, consistency, and reproducibility of tooth measurements by comparing conventional dental cast models with their digital equivalents. Materials and Methods: The research sample consisted of 50 before-treatment, diagnostic, conventional cast models utilized for study and evaluation. Tooth measurements on the dental cast models were done using a digitized Vernier caliper (Precision, IP54). Three-dimensional (3D) model tooth measurements were obtained through scanning the conventional cast models using the Maestro 3D Dental Scanner (Italy). The comparison of validity and reliability between conventional and digital cast models was done through independent t-tests, Cronbach’s alpha test, and intraclass correlation coefficient (ICC). Results: The Independent t-test showed no statistically significant difference between conventional and digital cast models. Cronbach’s alpha test demonstrated high reliability between conventional and digital cast models, surpassing 0.9 in this study. Intraexaminer reliability (ICC) was nearly perfect agreement ranging from 0.82 to 0.99. Conclusion: The digital cast models exhibited user-friendly features and were shown to be a feasible substitute for conventional dental cast models, providing similar levels of accuracy and effectiveness. Consequently, the dental arch tooth measurements of digital cast models were equally accurate and consistent when compared to those obtained from conventional dental cast models.

The Applicability of the Moyers, Tanaka-Johnston, and Gross-Hasund Analysis and a New Formula for the Vietnamese Population.

Our aim is to determine the applicability of other analyses and develop a new formula appropriate for the Vietnamese population. A cross-sectional descriptive analysis was conducted on a total of 120 dental arch samples (18-25 years old, 60 males, and 60 females) with <5 mm of tooth crowding, complete teeth on the dental arch, no missing teeth, and no fillings on the mesial or distal sides. Each study sample will be imprinted and measured using conventional as well as digital methods. There was a significant discrepancy between the overall mesiodistal width from canine to second premolar in the maxilla and mandibular measured with electronic calipers on the cast model and the values calculated by the Moyer, Tanaka - Johnston, Gross - Hasund formulae in the mandibular, and measured by digital scanning and results calculated by the Gross-Hasund formula for maxilla and mandibular and the Moyers, Tanaka-Johnston formula for mandibular. The values obtained were compared with those calculated using the Moyers, Tanaka-Johnston, and Gross-Hasund formulae for the mandibular. Additionally, measurements were taken by digital scanning, and the results were calculated using the Gross-Hasund formula for both the maxilla and mandibular, and the Moyers and Tanaka-Johnston formulae for the mandibular. When used to estimate space analysis in the Vietnamese population, the estimation formula for each gender had greater accuracy and reliability than other widely used methods. As the central incisor and first molar are the first permanent teeth to erupt, the mesiodistal width may be readily measured. This new formula may be used to predict the width in the early stages of the mixed dentition.

Betulinic acid ameliorates cast‐immobilized skeletal muscle atrophy but not denervation‐induced skeletal muscle atrophy

AbstractBackgroundTerpenoids have gained attention as therapeutic agents for skeletal muscle atrophy owing to their various physiological activities. In this study, we screened four terpenoids for their therapeutic potential against muscle atrophy in cultured cells and evaluated the effectiveness of betulinic acid in two disuse muscle atrophy models.MethodsC2C12 cells were used as the skeletal muscle model in cell culture experiments. Betulinic acid (100 mg/kg, twice daily) was administered to two different mouse models of muscle atrophy (established using the sciatic denervation and casting methods) for 7 days.ResultsIn myotube experiments, the mRNA expression of atrogin‐1 and myostatin was significantly suppressed by betulinic and ursolic acids (P &lt; 0.05). In the differentiation phase of C2C12 myotubes, the mRNA expression levels of myoD and myogenin were significantly increased by betulinic acid (P &lt; 0.05). In addition, apelin and irisin were also significantly increased by betulinic acid (P &lt; 0.05 and 0.01, respectively). Consequently, betulinic acid was administered to the aforementioned muscle atrophy models. Betulinic acid did not inhibit the decrease in skeletal muscle weight observed in the denervation model. However, it significantly inhibited the decrease in tibialis anterior (TA) and extensor digitorum longus (EDL) weights and grip strength observed in the cast‐immobilized skeletal muscle atrophy model (TA: Cast + Veh vs. Cast + Bet = 42.6 ± 1.0 vs. 46.0 ± 0.8 mg, P &lt; 0.01; EDL: Cast + Veh vs. Cast + Bet = 9.0 ± 0.4 vs. 11.3 ± 0.5 mg, P &lt; 0.01; grip strength: Cast + Veh vs. Cast + Bet = 222 ± 4.8 vs. 245 ± 3.6 g, P &lt; 0.05). In addition, betulinic acid administration partially inhibited the decrease in skeletal muscle cross‐sectional area.ConclusionsBetulinic acid alleviated muscle atrophy in the cast model of muscle atrophy and has therapeutic potential for the treatment of immobilized disuse skeletal muscle atrophy.

Bi-directional nasal drug delivery systems: A scoping review of nasal particle deposition patterns and clinical application.

To compare the deposition patterns within the nasal cavity between the bi-directional and unilateral nasal delivery systems. And to summarize the clinical application of the bi-directional nasal drug delivery devices. PubMed, Cochrane Library, Embase, and Web of Science databases. A scoping review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). We included studies exploring patterns and influencing factors of particle depositions within the nasal cavity among patients, healthy controls, and nose cast models using the bi-directional and unilateral nasal delivery system. The clinical application of the bi-directional delivery devices was also summarized. A total of 24 studies were included in this review. Bi-directional nasal delivery systems utilize forced exhalation to power the delivery of drugs to deeper areas of the nasal cavity and paranasal sinuses. Unilateral nasal delivery systems included traditional liquid spray pumps, the aerosol mask system, nebulization, and conventional nasal inhalation. Compared with unilateral delivery systems, the bi-directional nasal delivery system provided a more extensive and efficient nasal deposition in the nasal cavity, especially in the olfactory cleft, without lung deposition. Several parameters, including particle size, pulsatile flow, and nasal geometry, could significantly influence nasal deposition. The bi-directional nasal delivery system enables better delivery of steroids or sumatriptan to the sinonasal cavity's high and deep target sites. This bi-directional delivery device demonstrated an effective and well-tolerated treatment that produced high drug utilization, rapid absorption, and sustained symptom improvement among patients with chronic rhinosinusitis (CRS) or migraine. The bi-directional nasal drug delivery systems demonstrated significantly higher drug deposition in superior and posterior regions of the nasal cavity than unilateral nasal delivery systems. Further studies should explore its potential role in delivering drugs to the olfactory cleft among patients with olfactory disorders and central nervous system diseases. N/A.

Virtual Dental Articulation Using Computed Tomography Data and Motion Tracking.

Dental articulation holds crucial and fundamental importance in the design of dental restorations and analysis of prosthetic or orthodontic occlusions. However, common traditional and digital articulators are difficult and cumbersome in use to effectively translate the dental cast model to the articulator workspace when using traditional facebows. In this study, we have developed a personalized virtual dental articulator that directly utilizes computed tomography (CT) data to mathematically model the complex jaw movement, providing a more efficient and accurate way of analyzing and designing dental restorations. By utilizing CT data, Frankfurt's horizontal plane was established for the mathematical modeling of virtual articulation, eliminating tedious facebow transfers. After capturing the patients' CT images and tracking their jaw movements prior to dental treatment, the jaw-tracking information was incorporated into the articulation mathematical model. The validation and analysis of the personalized articulation approach were conducted by comparing the jaw movement between simulation data (virtual articulator) and real measurement data. As a result, the proposed virtual articulator achieves two important functions. Firstly, it replaces the traditional facebow transfer process by transferring the digital dental model to the virtual articulator through the anatomical relationship derived from the cranial CT data. Secondly, the jaw movement trajectory provided by optical tracking was incorporated into the mathematical articulation model to create a personalized virtual articulation with a small Fréchet distance of 1.7 mm. This virtual articulator provides a valuable tool that enables dentists to obtain diagnostic information about the temporomandibular joint (TMJ) and configure personalized settings of occlusal analysis for patients.

A Biomechanical Evaluation of Casting Technique and Cast Core Size Effect.

The goals of this study were to (1) compare the effect of casting technique on biomechanical function with different casting materials and different cast core diameters, and (2) compare the strength of a cast based on the number of layers in relation to the core diameter. Two standardized cylindrical cast model sizes were used to simulate forearm and short leg casts (core diameter: 60mm, 100mm) with 2 different casting techniques (non-smoothing vs. smoothing with lamination), utilizing 2 casting materials [fiberglass and Plaster of Paris (POP)]. Each cast was created using 3 different layers (Fiberglass: 2 to 4 layers; POP: 3 to 5 layers). Ultimate load-to-failure and flexural rigidity were analyzed through cyclic 4-point bend testing. The biomechanical comparison between forearm and short leg casts were significantly different regardless of the same number of layers for both casting materials and between 2 casting techniques. Increased cast thickness significantly increased the ultimate load-to-failure and bending strength. An increased core diameter size significantly decreased the cast's ultimate load-to-failure (fiberglass: 50% to 108%; POP: 10% to 93%) and bending strength (fiberglass: 17% to 35%; POP: 37% to 49%). Casting technique with smoothing with lamination technique had a negative biomechanical effect on POP and a minimal effect on fiberglass. The number of layers to apply for a cast should be based on the size of the extremity. Smoothing and lamination technique did not significantly improve the cast mechanical behavior. The findings of this study provide valuable evidence, analysis, and supplementary knowledge that helps guide physicians in proper casting technique.

Efficacy of alveolar ridge preservation with xenografts and resorbable socket sealing materials in the esthetic region: A systematic review with meta-analyses.

The present systematic review aimed to identify and summarize the clinical, radiographic, and histological outcomes of alveolar ridge preservation using bone xenografts and absorbable sealing materials compared with spontaneous healing in the esthetic zone. Randomized clinical trials (RCTs) fulfilling specific eligibility criteria were included. Two review authors independently searched for eligible studies, extracted data from the published reports and performed the risk of bias assessment (RoB 2 tool). Study results were summarized using random effects meta-analyses. Thirteen articles concerning 10 RCTs were included, involving a total of 357 participants. Most of studies were considered as "low" risk of bias. Meta-analyses indicated less horizontal (difference in means-MD = 1.88 mm; p < 0.001), vertical mid-buccal (MD = 1.84 mm; p < 0.001) and vertical mid-lingual (MD = 2.27 mm; p < 0.001) bone resorption in alveolar ridge preservation compared to spontaneous healing as assessed clinically. Bone changes assessed radiographically showed consistent results in terms of horizontal (at 1 mm: MD = 1.84 mm, p < 0.001), vertical mid-buccal (MD = 0.95 mm; p < 0.001) and mid-lingual (MD = 0.62 mm; p = 0.05) resorption. Part of the bone resorption in the spontaneous healing group was compensated by soft-tissues, since the observed differences between groups in linear ridge reduction evaluated through cast models superimposition were smaller (MD = 0.52 mm; p < 0.001). Alveolar ridge preservation with xenogeneic bone substitutes and non-autogenous resorbable socket sealing materials is efficacious in reducing post-extraction bone and ridge changes in the esthetic region.

Comparison of lower-body 3D-kinematics between Theia3D markerless and the CAST model marker-based systems during pathological gait in adults and children

Comparison of lower-body 3D-kinematics between Theia3D markerless and the CAST model marker-based systems during pathological gait in adults and children

Classification of 3D Casting Models for Product Lifecycle Management and Corporate Sustainability

The purpose of this study was to combine simulations and experiments in order to present the first stage of construction in product lifecycle management. Based on the simplification of casting models, the relationship between the filling and solidification characteristics, casting methods, and geometrical classifications of aluminum alloy precision casting products was investigated. By rearranging and summarizing the data, the casting models could be digitally managed; moreover, the digitized data could be used as the basis for intelligent processes in further developments. The simulations calculated and analyzed the casting speeds, defect locations, material densities, and critical fraction of a solid A356 aluminum–silicon alloy; the actual casting was carried out and samples were taken for metallographic observation to confirm the simulation results. The part model was simplified with four basic geometric shapes: solid cylinder, tubular, block rectangle, and thin-shell rectangle. The 150 casting models were summarized using 37 combinations, which were further classified into five main categories to match the casting method: solid cylindrical, tubular, and thin-shell rectangular for side casting, and discoidal and plate rectangular for bottom casting. File-compression rates of up to 75% were achieved after classification and archiving, and data integrity was maintained. Finally, model training using random forest classification resulted in an 88.8% accuracy when predicting the casting method. This research is based on the practical issues raised by business owners and R&amp;D engineers, and a solution was obtained. From the perspective of product lifecycle management, the results of this study show the consistency and uniformity of product design rules, as well as the reusability of product process planning, which can be integrated with carbon emissions trading and carbon taxes to save energy and achieve corporate sustainability.

Consumable additive FDM models in the production of aluminum alloy castings

This article describes the results of a study aimed at improving production technology of experimental castings from aluminum alloys by investment casting using models produced by 3D printing. The consumable models were produced using fused deposition modeling (FDM). Biodegradable polylactide (PLA) was used as a material for the models. In order to decrease the surface roughness of consumable PLA model. chemical post-treatment by dichloromethane needs to be performed. After immersion of the model into the solvent for 10s, its surface becomes smooth and glossy. Three-point static bending tests of PLA plates demonstrated a mechanical strength of average ~45.1 MPa. A thermomechanical analysis of polylactide demonstrated that in the course of heating of ceramic shell in excess of 150 °C, the polylactide model begins to expand intensively by exerting significant pressure on the ceramic shell. In order to decrease stress during the removal of polylactide model from ceramic mold, the heating time in the range of 150–300 °C needs to be heated to a maximum. The use of hollow consumable casting models with a cellular structure not higher than 30 % is also sensible. The stresses on the shell will not exceed its strength. Characteristic temperature properties of PLA plastic thermal destruction were detected using thermogravimetric analysis. Polylactide was established to completely burn out upon heating to 500 °C leaving no ash residue. Analysis of the results identified the burning modes of polylactide models from ceramic molds. Using a Picaso 3D Designer printer (Russia), the PLA models were printed used for production of experimental castings from aluminum alloys. It was revealed that the surface roughness (Ra) of a casting produced using a consumable model treated by dichloromethane decreases by 81.75 %: from 13.7 to 2.5 μm.

EFFECTS OF 2x4 APPLIANCE AND NiTi OPEN SPRING ON MIXED DENTITION

Background/Objectives: The mixed dentition period is the best time to guide the occlusion and intercept a malocclusion. Among the preventive orthodontic procedures, space recovery is considered extremely important for the biogenesis of the occlusion to follow its normal course. Several orthodontic appliances indicated for space recovery in mixed dentition are mentioned in the literature and among them, mechanics with a fixed 2x4 partial appliance.This study aimed to evaluate changes in the dimensions of the upper arch after using a 2x4 fixed partial appliance with expanded CuNiTi wires and open NiTi springs. Material and Methods: Twenty-four children (±9 years) were assessed who had no space for the eruption of permanent teeth in the upper arch, treated with a 2x4 fixed partial appliance. Lateral teleradiography imaging, panoramic radiography and cast models were used before and after the treatment. The results were compared to a control group of 24 children who did not receive treatment and had their documents assessed for growth-related changes. The following changes were evaluated: dimension of arch perimeter, arch depth, intermolar distance, and inclination and displacement of permanent upper molars and incisors. Student’s t-test was used to assess the differences between pre- and post-treatment times, with significance level of 5%. Results: Increases were observed in arch perimeter (p=0) and arch depth (p=0) due to a distal movement of the crown (p=0) and the root of molars (p=0.004), and maintenance of the spatial position of the incisors, without protrusion (p=0.37) or vestibular movement (p=0.13). Limitations: the limitation of the present study was not to randomize the sample and not to use a control group identical to the group that received treatment. Conclusion: 2x4 fixed partial appliance was effective for the recovery of mixed dentition space, increasing the arch perimeter and depth through a distal movement of the upper molar and maintenance of incisor position.

Evaluation of the Influence of Technological Parameters of Selected 3D Printing Technologies on Tribological Properties.

The article presents the results of tribological research of sample models manufactured using three separate 3D printing technologies: selective laser sintering-SLS, photo-curing of liquid polymer resins-PolyJet Matrix (PJM) and fused deposition modeling-FDM. The impact of process parameters (printing direction, layer thickness, and energy density for SLS) on tribological properties was assessed through linear wear and coefficient of friction. The research was carried out to assess the possibility of using 3D printing for the quick manufacturing of casting models, which has a significant impact on shortening the time of implementation for mass production of the casting process. The research results proved the possibility of controlling the technological process in a manner allowing to produce models with controlled properties, including tribological parameters. In addition, the results for three additive technologies and different materials were compared by using the same friction parameters.

Methods of Evaluating Adaptation and Accuracy of Additive Manufactured Removable Partial Dentures: A Scoping Review

This study aimed to provide a comprehensive review of various recent methods that can be used to assess the fit and accuracy of additive-manufactured removable partial dentures (RPDs), focusing on 3D-printed RPDs. An electronic search of the English language literature from January 2000 to February 2022 was performed using four databases: Medline/PubMed, Scopus, Web of Science, and EBSCOhost, using relevant keywords. The parameters of interest were extracted and tabulated. Of 936 retrieved studies, 26 studies were included. Most of the studies were laboratory studies, conducted between 2011 and 2022, did not include control group, used stone cast model as reference, used direct 3D printing method, and polished the final RPD framework. Methods of assessment can be divided into two categories: 1) qualitative assessment which is based mainly on visual inspection or tactile sense, and 2) quantitative assessment which includes optical assessment (with or without a registration material) and computerized assessment based on surface-matching software programs. In conclusion, computerized assessment using different surface matching software provides more accurate and precise quantitative assessment of denture fit and allows researcher and practitioner to detect minute dimensional changes that cannot be detected visually.

A Three-Year Prospective Study Comparing Stereolithography Printed Models to Classical Impression and Plaster Cast Models in Orthodontic Therapy: A 3D Objectification Approach

The integration of computational intelligence and augmented reality has become increasingly prevalent in dental practices. Three-dimensional (3D) printing techniques have now become routine in orthodontics, prosthetics, and maxillofacial surgery. The objective of this study is to assess the effectiveness of stereolithography (SLA) printed models compared to traditional plaster casts over a three-year period. The experimental dataset consisted of 36 orthodontic patients, each with SLA printed models and plaster casts for both the upper and lower jaws, resulting in a total of 72 scans in the form of Standard Template Library (STL) files and 72 traditional impressions. The upper dental arch models were constructed using an SLA 3D printer, employing a blue 405 nm laser beam to solidify a liquid polymer. The classical plaster casts were prepared in a dental laboratory. The models were retained for long-term orthodontic therapy control. To evaluate the differences between the dental models, a laboratory scanner was used to generate virtual casts. The meshes obtained were adjusted and pre-aligned using the best-fit algorithm. Subsequently, registration of the models was performed using the iterative closest point (ICP) algorithm. Distances between the point clouds and meshes for each point of the printed model were calculated by determining the nearest triangle on the reference mesh (cast). Additionally, the model surfaces were assessed using a scanning electron microscope and a stereomicroscope. The results from 22 experimental datasets indicated a high level of agreement between the plaster casts and virtual surfaces, with a mean absolute difference of 0.018 mm and a standard deviation of 0.17 mm. These values were obtained by averaging 231,178 data points for each comparison. Overall, this study demonstrates the comparability and accuracy of SLA printed models in relation to traditional plaster casts, supporting their potential as reliable alternatives in dental practice.

A facile, semi-automatic protocol for the design and production of 3D printed, anatomical customized orthopedic casts for forearm fractures

Closed fractures of distal radius and ulna are one of the most common skeletal injuries, occurring at all ages. Temporary arm immobilization through cast is part of the standard treatments. However, traditional casting procedures are time consuming, operator's skill dependent and do not always guarantee a satisfactory outcome. From a clinical perspective, casts are often considered uncomfortable and can be associated to skin lesions. To overcome these limitations, the recent growth of 3D technologies has enabled new standardized casting procedures: additive manufacturing (AM) is a technique that creates highly customized cast models from anatomical 3D data by using digitally controlled and operated material laying tools. Compared with conventional casts, those produced with AM technique could potentially reduce skin complications and satisfy both mechanical and clinical requirements of functionality, comfort, and aesthetics.The objective of this study is to describe the new practical methodology to produce a 3D printable cast for upper arm immobilization. The parametric modelling tool, employed to develop a semi-automatic design system for generating the printable cast model, reduces the complex process of orthosis design to a few minutes and all the manufacturing operations remain unaffected by CAD skills of the operator. Specific hardware and software tools (3D scanner, modelling software and FDM technology) were chosen to mitigate design and production costs while guaranteeing suitable levels of data accuracy, process efficiency and design versatility. To highlight the effectiveness of the proposed solution, a finite element analysis simulation was performed on models with different geometry, highlighting the mechanical strength of generated structures.The final result is a personalized 3D printed cast with a highly ventilated structure that is lightweight but still maintains a high level of strength and provides hygienic benefits, reducing the risk of cutaneous complications, potentially improving treatment efficacy and increasing patient satisfaction.

Regeneration processes of alveolar bone and microvascular changes after the application of platelet-rich fibrin

ObjectivesPlatelet-rich fibrin (PRF) is a promising agent for bone regeneration (BR). Platelets contain several growth factors that promote angiogenesis and BR. In this study, we observed the morphology of alveolar BR. MethodsPRF (Advanced PRF: A-PRF) was prepared by extracting 10 mL of blood from each dog in a collection tube before tooth extraction. The samples were centrifuged at 200 × g for 8 min and incubated for 10 min to allow clotting. The alveolar socket on the dentition's right side was densely filled with PRF. The opposite side, which did not receive PRF, served as the control group. Different methods were used for specimen preparation and observation. Sections stained with hematoxylin and eosin were observed under a light microscope. Bone specimens were observed using stereoscopic microscopy. The resin cast models were examined using a scanning electron microscope. Moreover, bone formation ratio and height were measured. ResultsFourteen days postoperatively, angiogenesis and bone deposition were more advanced in the PRF group than in the control group. Thirty days postoperatively, both groups developed porous bone. In the PRF group, new bone trabeculae (BT) and a network of blood vessels were formed in the bone marrow. Ninety days postoperatively, the resin cast showed a normal bone structure with BT and bone marrow. Thick BT were observed in the PRF group. ConclusionsGrowth factors in PRF stimulate microcirculation and promote angiogenesis and bone deposition. The benefits of PRF include safety and increased bone formation.

Nasal cast deposition for xylo- and oxymetazoline formulations using two different nasal pumps

Background: Allergic rhinitis, rhinosinusitis, and upper respiratory tract infections, including the common cold, are caused by inflammation of nasal cavity areas. A key symptom is nasal congestion, which can be relieved with nasal spray medications. A key goal in developing a nasal spray medication delivery device for the relief of nasal congestion is delivering a fine mist to the inflamed areas while providing user comfort and convenience. Methodology: Using a Koken nasal cast model, we studied the deposition patterns of 2 xylometazoline and 1 oxymetazoline for- mulations with 2 different nasal pumps, the currently marketed Freepod and the investigational laterally actuated device. Effects of nasal tip orientation and breathing were investigated. Additionally, the degree of xylometazoline and oxymetazoline dripping down the back of the cast was assessed. Results: The largest coverage overall was observed with the xylometazoline formulation with the laterally actuated pump and without breath simulation. The laterally actuated pump used at a 30° angle resulted in deposition to the inferior, middle, and superior turbinates of the nasal cast, with less variability than the Freepod. Drippage at the back of the cast was observed with the Freepod device but not with the laterally actuated device. Conclusions: Using a nasal cast model, the laterally actuated pump used at a 30° angle produced a full mist covering areas inflamed with the common cold, allergic rhinitis, and rhinosinusitis with no dripping at the back of the cast, an improvement compared with the Freepod pump. In vivo studies are needed to confirm nasal cast results.