Removable Systems Research Articles

Prosthetic Oral Rehabilitation with CAD/CAM Suprastructures in Patients with Severe Tissue Deficits: A Case Series.

This article presents the outcomes of prosthetic oral rehabilitation using CAD/CAM telescopic bar overdentures in patients with oral cancer (n = 3), severe facial trauma (n = 2), or various syndromes (n = 1), all suffering from severe tissue deficits and requiring complex and comprehensive oral rehabilitation. The aim was to assess the durability and functionality of implant-retained prosthetic structures, ensuring easy oral hygiene and minimizing specialized follow-up needs. The data for this study were sourced from a retrospective cohort at Helsinki University Hospital. The prosthetic reconstruction encompassed the Atlantis 2in1 and the Createch removable telescopic systems. Thus, 40 implants were placed (4 to 7 per patient), with prosthetic structures in the maxilla (n = 4 patients), in the mandible (n = 1), and in both jaws (n = 1). Two patients experienced no complications, two patients had part of the acrylic resin break, and one patient experienced loosening of the bar structure. All complications associated with prosthetic structures were successfully managed, and none of the implants were lost. The follow-up time ranged from 7 to 126 months. This rehabilitation is proved to be an effective solution for patients with complex oral conditions, facilitating both functional restoration and ease of maintenance. These findings underscore the importance of individualized treatment approaches in cases of tissue deficits.

Orthodontic Relapse after Fixed or Removable Retention Devices: A Systematic Review

Retention constitutes a fundamental phase of orthodontic treatment, of which the patient must be made aware from the outset. Retention, which can be fixed or movable, has the task of maintaining over time and stabilising the results obtained during treatment. This study assessed the efficacy of using removable restraints versus fixed solutions for maintaining long-term outcomes. A comprehensive search across major databases—Pubmed, Web of Science, Scopus—used ‘relapse’ and ‘orthodontic’ as keywords to gather articles on relapse discussions. The primary focus was relapsed cases in post-fixed orthodontic therapy. Both fixed and removable retainer systems prove effective in preserving orthodontic achievements. While fixed devices require regular wire integrity checks, mobile devices require patient compliance, proper usage, and a recommended wear time. Studies indicate that fixed retainers are generally successful, with relapse rates varying based on the retainer type. Full-time use of removable devices surpasses night-only wear. Vacuum-formed and Hawley retainers offer similar effectiveness. Fixed retainers excel in long-term alignment stability, whereas removable ones have higher failure rates yet remain beneficial.

Improving Reinforced Concrete Column Strengthening Techniques for Reconstruction Projects Using Composite Jacketing Formworks

The paper looks at the issues of reconstruction of modern construction systems, in particular, the possibility of their functional repurposing. Examples from the global practice are provided to illustrate the conversion of industrial facilities for use as residential and public buildings. Based on an overview of scientific publications, the paper offers a set of rationales for the preservation of industrial facilities and highlights the benefits of reconstruction aimed at improving their residual lifespan and ensuring further reliable operation. Reconstruction is noted to enable resource savings, which allows efficiently investing in the development of modern machinery and technology as well as launching production of innovative products. Interior details are displayed as an example of industrial building conversion into a preschool educational facility. The purpose of the study is to improve the techniques of enhancing the bearing capacity of reinforced concrete columns by using composite materials and reducing related labor inputs. To this end, it is suggested that removable or permanent formwork systems be replaced with a jacketing formwork combining the benefits of both removable formworks (quick turnaround, adaptability due to the use of high-strength and light-weight composites) and stay-in-place formworks (the factory-made decking forms part of the column to be reinforced and does not require extra finishing). The paper argues that a jacketing formwork is multifunctional, as it performs the protective function in addition to the molding one, and provides the description and schematic design featuring two formwork options. The use of jacketing formworks allows reducing labor inputs when reinforcing columns and restoring their geometric dimensions, thus cutting down on the overall reconstruction time. A conclusion is made that the use of modern composite materials for manufacturing jacketing formworks allows not only making or reinforcing rectangular-section columns, but also changing the geometric configuration of the cross section for reconstruction purposes.

System-Level Consideration and Multiphysics Design of Propulsion Motor for Fully Electrified Battery Powered Car Ferry Propulsion System

The Korean government is facing growing concern over the increasing levels of fine dust. A significant contribution to this problem comes from coastal vessels. To mitigate this, an electric ship propulsion system has been proposed as a solution to reduce air pollution. The application of a fully electric propulsion system in a ship is challenging due to size, capacity limitations, and the cost investment of the battery system. To address the challenges of battery limitation and initial investment costs, the development and supply of removable battery supply systems (RBSSs) for fully electrified battery powered (F-EBP) car ferries are studied. A permanent magnet synchronous motor (PMSM) for the F-EBP car ferry using a roll-on/roll-off-type RBSS is developed in this work. Firstly, the concept of the F-EBP car ferry is discussed, and the specifications of the electric car ferry propulsion system are provided. Secondly, motor design and electromagnetic analysis are performed using finite-element analysis (FEA), where the heat sources including copper loss, core loss, and PM loss are calculated. Mechanical loss is also considered. Finally, a thermal network of the motor is built considering the lumped-parameter model. The results of the thermal analysis indicate that the motor operates within the safe region and can perform well in rated working conditions.

Current Implementation of Digital Dentistry for Removable Prosthodontics in US Dental Schools.

Objectives Although digital technology has been widely integrated into dental education, there is limited literature investigating the extent of the integration of computer-aided design and computer-aided manufacturing (CAD-CAM) for removable systems in the dental curriculum. The purpose of this study was to assess the current implementation of CAD-CAM complete and partial dentures in predoctoral (PP) and advanced graduate prosthodontic (AGP) education in US dental schools. The study also aimed to identify potential barriers to its implementation in the dental curriculum. Methods An online survey with 15 questions was created using online survey software. The survey was distributed to the directors of predoctoral prosthodontics in 56 schools and advanced graduate programs of prosthodontics in 52 schools listed in the 2018–19 American Dental Education Association (ADEA) Directory. Results The percentage of programs (PP and AGP) implementing CAD-CAM complete dentures (CAD-CAM CDs) and CAD-CAM removable partial dentures (CAD-CAM RPDs) in their didactic, preclinical, and clinical curricula was recorded. CAD-CAM CDs are taught in didactic courses in 54.2% of PP and 65.2% of AGP. However, CAD-CAM RPDs are only taught in 37.5% of PP and 47.8% of AGP. Programs are largely limited by a lack of funds, resources, time, and faculty members. Conclusion While digital technologies have indeed become more prevalent in dental education, many institutions face barriers to implementation. More research must be conducted in order to support the continued incorporation of digital technologies into dental education.

Comparative Analysis of Periodontal Pain Using Two Different Orthodontic Techniques, Fixed Multibrackets and Removable Aligners: A Longitudinal Clinical Study with Monthly Follow-Ups for 12 Months

The aim of this study was to evaluate the perception of periodontal pain in patients treated with either fixed multibrackets or removable alignment systems with a monthly follow-up over a period of twelve months. Materials and Methods: This longitudinal clinical study comprised a sample of 140 patients (72 women; 68 men) divided into two groups of 70 patients each: the bracket group (BG) with conventional fixed brackets using the MBT technique with a 0.022″ slot and the Invisalign group (IG) with aligners (Invisalign). The visual analog scale (VAS) was used to quantify patient-reported pain. Pain analysis was conducted monthly at 4 (T1), 8 (T2), and 24 h (T3) post-follow-up as well as at 2 (T4), 3 (T5), 4 (T6), 5 (T7), 6 (T8), and 7 days (T9) post-follow-up during the first twelve months after starting orthodontic treatment. Results: Statistically significant differences (p < 0.05) were observed between both study groups in the mean pain scores on the visual analog scale (VAS) during the twelve-month follow-up period, except for during the eighth month of treatment. In the first month, the group with conventional brackets reported higher pain scores. From the second month onwards, we observed that patients with aligners described a higher level of pain compared to the group of patients with conventional brackets. In both experimental groups, though at different evaluation periods, we found that the peak of maximum pain occurred between 24 and 48 h (T3–T4) after monthly follow-up appointments; from this point, the pain decreased until reaching minimum values from the fifth day onwards (T7). Conclusions: In the first month of treatment, the patients with conventional fixed multibrackets reported the highest levels of pain compared to those with removable aligners. From the second month on, this trend changed. The patients with removable aligners reported the highest levels of pain. Therefore, the orthodontic system used influenced the perception of pain in patients.

Study on a Fully Electrified Car Ferry Design Powered by Removable Battery Systems Considering Domestic Coastal Environment

As increasing the international community’s awareness of greenhouse gas reduction, the demand for eco-friendly ship fuel has accelerated recently. The fundamental aim of this study is to develop a new type of fully electrified ferry for passengers and cars considering Korean domestic coastal environmental conditions. Several technical difficulties are encountered in applying a fully electric propulsion system based on removable battery systems into a ship due to limitations imposed by the batteries’ size and capacity. This paper reviews and analyzes marine environment regulations strengthened recently, technology trends related to fully electric propulsion vessels in each country, and Korean domestic coastal environments. We propose a new fully electrified car ferry design with a displacement of 400 t applied in Korea. It is powered by removable battery systems pre-charged in a safe inland charging station. The mobile battery system is developed to enable roll-on and roll-off using wheels. The characteristics of the ship motion are analyzed based on the weight and location of the battery systems. We expect our battery systems to be applicable to larger ships in the future.

Efficient Performance Technical Selection of Positive Buck-Boost Converter

The necessity for stable DC voltage in both removable and non-removable systems has been considerably desired recently. These systems have to be implemented efficiently in order to be responding rapidly based voltage variations. Under this act, the efficient power can extend the lifetime of the employed batteries in such systems. The presented efficiency can be realized with respect to buck and boost components that were implemented to generate what is called positive Buck-Boost converter circuits. The main functions of the positive Buck-Boost converter are identified by announcing the unchanged situation of output voltage polarity and indicating the level of the voltage rationally between the input and the output. It is worth mention, the positive Buck-Boost converter circuit was simulated based Proteus software, and the hardware components were connected in reality. Finally, the microcontroller type that employed in the proposed system is PIC_16F877A, which realizes the input voltage sensitively to generate Pulse Width Modulation (PWM) signals in order to feed the employed MOSFET element.

Photoelasticity in Dentistry: a literature review

Photoelasticity consists of an experimental technique of stress analysis. This technique is very used in most different areas including Dentistry. This literature review presents the several applications of photoelastic technique in Dentistry the several applications of photoelastic technique in Dentistryas well as its advantages and disadvantages. Literature review:Based on this method of analysis, it is possible the verification of the stress distribution and deformation in structures with complex geometry as maxilla and mandible. It can be used to evaluate the distribution of stress on several types of prosthesis as removable partial denture systems with different retention systems, conventional implant prosthesis, overdentures and Brånemark protocols. Moreover, photoelasticity can be used to assess the stress generated by various by various orthodontic movements, different orthodontic systems and different materials (orthodontic wires). In addition, it is used to analyze different defects of maxillectomy, splint types on traumatized tooth and post-core restoration methods. This technique can also be used to assess dental instruments such as evaluation of different designs of periodontal probe. Conclusion: The photoelastic analysis has been a technique of great importance in health area studies, more specifically in Dentistry. Based on this method of analysis, it is possible to measure the stress distribution and deformation in structures with complex geometry as maxilla and mandible.

Influence of drugs on orthodontic tooth movement

Orthodontics is a specialty, using biomechanical principles of physiological mechanisms that can correct dental malposition and malformations of the jaws to restore a functional and aesthetic dentition. Orthodontic treatments are limited to dental displacements, using either fixed or removable systems. Only the alveolar bone needs to be remodeled. Dent facial orthopedics treatments also include the control and modification of jaw positions and facial growth by controlling the growth sites in the maxilla and mandible [1, 2]. When a force is applied to the crown of a tooth, it is transmitted through the root of the tooth to the periodontal ligament and alveolar bone. According to the direction of the force, there will be areas of pressure and areas of tension on these supporting structures [

A Study of Practical Proxy Reencryption with a Keyword Search Scheme considering Cloud Storage Structure

Data outsourcing services have emerged with the increasing use of digital information. They can be used to store data from various devices via networks that are easy to access. Unlike existing removable storage systems, storage outsourcing is available to many users because it has no storage limit and does not require a local storage medium. However, the reliability of storage outsourcing has become an important topic because many users employ it to store large volumes of data. To protect against unethical administrators and attackers, a variety of cryptography systems are used, such as searchable encryption and proxy reencryption. However, existing searchable encryption technology is inconvenient for use in storage outsourcing environments where users upload their data to be shared with others as necessary. In addition, some existing schemes are vulnerable to collusion attacks and have computing cost inefficiencies. In this paper, we analyze existing proxy re-encryption with keyword search.

Hydrogel Networks Based on Aba Triblock Copolymers

Triblock copolymers from hydrophilic oligo(ethylene glycol) segment A and oligo(propylene glycol) segment B, providing an ABA structure (OEG-OPG-OEG triblock), are known to be biocompatible and are used as self-solidifying gels in drug depots. A complete removal of these depots would be helpful in cases of undesired side effects of a drug, but this remains a challenge as they liquefy below their transition temperature. Therefore we describe the synthesis of covalently cross-linked hydrogel networks. Triblock copolymer-based hydrogels were created by irradiating aqueous solutions of the corresponding macro-dimethacrylates with UV light. The degree of swelling, swelling kinetics, mechanical properties and morphology of the networks were investigated. Depending on precursor concentration, equilibrium degree of swelling of the films ranged between 500% and 880% and was reached in 1 hour. In addition, values for storage and loss moduli of the hydrogel networks were in the 100 Pa to 10 kPa range. Although OEG-OPG-OEG triblocks are known for their micellization, which could hamper polymer network formation, reactive OEG-OPG-OEG triblock oligomers could be successfully polymerized into hydrogel networks. The degree of swelling of these hydrogels depends on their molecular weight and on the oligomer concentration used for hydrogel preparation. In combination with the temperature sensitivity of the ABA triblock copolymers, it is assumed that such hydrogels might be beneficial for future medical applications - e.g., removable drug release systems.

Current developments in transcatheter aortic valve implantation techniques

Transcatheter aortic valve implantation (TAVI) has become a viable treatment option in high-risk patients with symptomatic aortic stenosis. The widespread uses of TAVI procedures in recent years and the steadily growing evolution of numerous new catheter-based devices have led to a remarkable shift in the treatment of this patients group towards TAVI procedures. Several developments have now overcome most of the initial problems with the early devices and have been quickly implemented in clinical routine. Nevertheless, several current TAVI systems have shown a number of limitations and disadvantages relating to valve design, the occurrence of paravalvular leakages, valve positioning and deployment, the occurrence of thromboembolic events during the procedure, as well as vascular or conduction complications. As a result, all current efforts in further development focus primarily on the following issues: (1) the further miniaturization of catheter devices and sheaths not only to facilitate transarterial but also transapical access; (2) the development of a broad variety of valve sizes to cover all aortic annulus sizes; (3) the development of retrievable, repositionable and removable systems; (4) the development or modification of stent design to prevent or reduce paravalvular leakages; (5) the implementation of modern imaging and navigation tools; (6) and finally, the initial development of prophylactic devices to prevent thromboembolic events. The present article provides a review of current developments in the field of TAVI.

SU-FF-T-260: Image Fusion Reduces Errors for Mobile Tumors and Stereotactic Radiotherapy in IGRT

Purpose: To evaluate set‐up error for mobile tumors:lung,liver, and prostate under image‐guidedradiotherapy, and accuracy for cranial stereotactic radiotherapy with fixed (SRS) or removable frame systems (SRT). Methods and Materials: Twenty‐six patients with lung,liver or prostate cancer were implanted with 3 gold markers inside in the tumors. Markers and planning isocenter coordinates were transferred to a fusion system. Patients were positioned according to skin tattoos and lasers followed by stereoscopic KV x‐ray acquisition. The x‐ray sets were then fused with corresponding digital reconstructed radiographs (DRRs) of the plan. New skin tattoos were made after fusion on the first treatment day. For extracranial treatments, markers were manually matched between the x‐ray images and DRRs. Auto‐fusion matching bone structures was applied for SRS/SRT. Deviations between actual and planning isocenters were determined by the fusion software. Results: Average prostate motions plus setup errors in the lateral, longitudinal and vertical directions were (mean ± one standard deviation): 3.0±1.5 mm, 2.4 ± 1.0 mm, and 4.2 ± 1.8 mm, among 24 patients each treated with 25–45 fractions. Errors >10 mm in one of the three directions was found in 1.9% of the total 1773 measurements. Errors >5mm, occurred in 10.8%, but the rate reduced to 7.5% if 4 patients were excluded from the analysis. Errors for the lung following 32 fractions were: 3.3 ± 4.4 mm, 3.3 ± 2.9 mm, and 1.7 ± 1.2 mm. For liver the errors were: 4.2 ± 3.1 mm, 4.6 ± 4.6 mm, and 2.6 ± 2.7 mm. No error >2.0 mm occurred for SRS, but 15% exceeded 2.0 mm for SRT despite with good immobilization device. Conclusions: Use of image fusion provides a reliable method to evaluate quality of immobilization, verify and increase treatment accuracy. Results from this investigation may have implications for appropriate tumor margins for different sites and techniques.

Laparascopic Sampling of Roots of Known Age from an Expandable‐Wall Minirhizotron System

Root system changes in response to experimental treatments may be due to a number of factors, which can be separated only by sampling roots of known age. Minirhizotrons allow for video recording of the growth of individual roots; subsequent removal of the minirhizotron would allow sampling of the roots under observation. A design for a removable minirhizotron with mechanically expandable walls is described in this paper, along with the use of laparascopic tools for sampling roots from removable minirhizotron systems. Laparascopic tools used in conjunction with removable minirhizotrons may be useful in field studies of the effects of root age and experimental treatments on root composition, physiology, and pathology; rhizosphere microbial ecology; rhizosphere mineralogy; and the dynamics of mycorrhizal colonization.

Advanced Storage Magnetooptical Disk (AS-MO) System

Advanced Storage MagnetoOptical Disk (AS-MO) is one of the highest density media for removable systems. By employing a read power control method, AS-MO has a capacity of 6 GBytes with wide system margins in a 120 mm single sided disk, and can be used under various conditions. The disk has many advantages for both AV and PC applications.

The rewritable MiniDisc system

The MiniDisc system was designed with the obvious objective of replacing the conventional Compact Cassette tape recorder system. The MiniDisc format defines two types of optical discs. One is a recordable magneto-optical disc for user recording and another is a conventional read-only disc for music-software publishing. Audio data compression is used to achieve 74 min of playing time on a 64-mm disc. By means of a built-in buffer memory called Shock Resistant Memory, MiniDisc can be used for outdoor portable application with great ease. Furthermore, MiniDisc was evolved to MD Data system and with a data capacity of 140 Mbytes and a very compact size, the MD Data system is expected to become one of the standards for removable data storage systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Improving palatal attachments.

A major disadvantage of removable palatal arch systems is the tendency for the palatal sheath to fracture from the band. The present study tests three methods of attaching the sheaths to molar bands. The results show that flush soldering after spot welding significantly increases the strength of their attachment to the band, without reducing the strength of the sheath.

Improving palatal attachments

A major disadvantage of removable palatal arch systems is the tendency for the palatal sheath to fracture from the band. The present study tests three methods of attaching the sheaths to molar bands. The results show that flush soldering after spot welding significantly increases the strength of their attachment to the band, without reducing the strength of the sheath.