Slot Dimensions Research Articles

Evaluation of dimensional accuracy and surface roughness of lingual bracket slot –An in vitro study

The paradigm shift with the increasing number of adults and teens seeking aesthetic options for orthodontic treatment led to the increased demand for lingual orthodontics. When it comes to size and slot dimensions, lingual brackets are very different from labial brackets.With the rise of lingual orthodontics in our everyday practice, it's more critical than ever for practitioners to understand these potential bracket size variations. The resistance to sliding mechanics can occur if the contact angle between the archwire and bracket increases, this creates the need for precise bracket slot dimension. The amount of friction varies proportionally to the accuracy of the dimensions and the roughness of the bracket slot.To evaluate the precision of commercially available orthodontic lingual bracket slots in inch dimensions with manufacturers’ published dimensions using a stereomicroscope and to compare the surface roughness of commercially available orthodontic lingual bracket slots using an atomic force microscope.Lingual brackets from four different manufacturers were taken for evaluation of slot dimensions. Twenty brackets of each manufacturer were randomly selected. Trinocular Stemi 2000 Stereo Zoom Microscope with Digital Camera (Carl Zeiss, Germany) was used for measurement of bracket slot dimensions. An atomic Force Microscope (AFM) (Nanoscope® IV Di digital instrument, California, USA) was used to evaluate the surface roughness of lingual bracket slots. Comparison of dimensions between mesial processes and comparison of dimensions between distal processes showed that the difference was only marginal with no significant statistic value. Statistically significant results proved that slot dimensions were not precise as per the manufacturer’s standards for given lingual brackets and were oversized for all bracket systems. Statistically insignificant results showed that the bracket systems were similar concerning the surface roughness of the bracket.The analyzed series of lingual bracket systems exhibited significant differences with manufacturers’ standards in slot dimension, which will clinically result in torque play. Lack of standardization of slot dimensions during the manufacturing process may be clinically associated with undesirable tooth positioning and movement; inferring that the bracket systems were similar concerning the surface roughness of the bracket slot.

A method for accurate extraction of three-dimensional point cloud feature data in loading test of container ships

The accuracy of container slot dimensions directly affects the efficiency and safety of container loading and unloading. However, traditional methods of container loading tests need to be improved for their long cycles, high costs, and low production efficiency. With the application of three-dimensional laser scanning devices in ship manufacturing, the use of simulated container loading test methods based on point cloud becomes a breakthrough in key technology for container ship construction. This paper presents a multi-objective segmentation method of cargo hold feature point cloud for container ship simulated loading tests. Data preprocessing algorithms are applied to remove noise and pseudo-image, and then a Random Sample Consensus algorithm is used to remove bulkhead and cargo bottom point clouds. Based on the density-based spatial clustering of applications with noise algorithm and the region growing algorithm, an algorithm for multiple segmentation of guide rail and bottom cone point clouds is devised, and a four-plane segmentation of guide rail point clouds is realized. Finally, a method for three-dimensional point cloud data flatness assessment and a Hausdorff distance based method for calculating the guide rail lateral and longitudinal spacing are proposed. These methods are validated through the loading test of a 16,000 TEU container ship.

Optimizing microwave heating with slotted metal tubes for cylindrical loads

Cylindrical loads are commonly encountered in microwave heating and often suffer from uneven thermal distribution. Within certain radius and dielectric parameter ranges, cylindrical loads may exhibit central thermal focusing. This paper proposes a novel microwave heating method employing a slotted metal tube (SMT) to encase the cylindrical materials. The SMT alters the electric field distribution and enhances the coupling of microwave energy, thereby improving the heating uniformity and efficiency. We first developed a simulation model for microwave heating, analyzing how permittivity and dimensions affect the thermal focus of cylindrical materials. By optimizing the slot dimensions and positions, we overcome the thermal focusing phenomenon. Then, we conducted microwave heating experiments with mashed potatoes, showing that the use of SMT improved the temperature uniformity by 38 % and increased the microwave energy conversion efficiency by 48 %. Furthermore, we applied SMT to a more challenging scenario, involving the heating of cylindrical canned foods with metal lids, using a dual-source heating setup. The experimental results indicated that SMT remained effective in enhancing heating uniformity and efficiency. This method contributes to the development of microwave energy industrial applications, providing innovative solutions for cylindrical load heating.

Simulation of High-Gain Microstrip Patch Antennas for 5G Applications

This paper presents a single-band Microstrip Patch Antenna (MPA) with L, T, and other suitable slots, specifically designed for high-gain performance in fifth-generation (5G) mobile communication systems. Incorporating these innovative slots onto a single rectangular patch antenna yielded substantial improvements in gain and bandwidth, addressing the requirements of 5G applications. The investigation was conducted within the Computer Studio Suite (CST) simulation environment, utilizing simulated structures to identify optimized slot dimensions. The performance and dimensions of the newly modified patch antennas are systematically assessed and compared against those of a previously developed single microstrip patch antenna and an array designed for operation at 28 GHz. The results of the proposed antennas exhibited significant gain and directivity, noticeable bandwidth, Voltage Standing Wave Ratio (VSWR), and efficiency at the selected resonance frequency. The successful implementation of this proposed design holds the potential to greatly simplify the integration of 5G applications into handheld devices.

A scanning electron microscopy investigation of the precision of three orthodontic bracket slot systems

ObjectiveOne of the most imprortant factors in achieving ideal teeth positions is the precision of the slot dimensions of orthodontic brackets into the archwires are inserted.This study aimed to assess the accuracy of the dimensions of orthodontic bracket slots and molar buccal tube apertures and to compare them with the specifications provided by the manufacturers.MethodA total of sixty brackets and ten molar buccal tubes with varying slot heights were examined using a scanning electron microscope from the mesial side. The dimensions and morphology of these bracket slots and buccal tubes apertures were assessed using the AutoCAD Software. A one-sample t-test was conducted to compare the measurements with the values provided by the manufacturer.ResultsThe findings of the present study indicated that the height of the measured bracket slots and buccal tube apertures dimensions were significantly larger than the actual dimensions and exhibiting divergent walls. On the other hand, the depth of the brackets slots showed significantly smaller values than the actual one.ConclusionA need for careful consideration when selecting a commercially accessible brand for everyday use is essential as certain materials may not meet acceptable standards.

Model of slot antenna for MPECVD of carbon nanostructure

A model of a slotted waveguide antenna for microwave plasma enhanced chemical vapor deposition (MPECVD) of carbon nanostructures at low pressure is developed. The performance of two slot applicator for the production of dense plasma in the working gas (argon) at a frequency of 2.45 GHz is investigated by EM field simulator. Results show that dimensions of the symmetrical slots (length l ≤ λg/2, width of d = 6-10 mm) and optimized angle (φ=32° with respect to the waveguide central line) have a strong influence on the impedance matching of the waveguide to the dielectric window and plasma column (1.5 < SWR < 2.5), and on the radiation efficiency. The dielectric plate and plasma column density were taken into account in the model in the optimisation of the dimensions of the slots. The mode structure of standing surface waves in the plasma column is investigated at three values of plasma density and results for the radial (n=1) and azimuthal wave numbers (m=3, 4, 5) are in agreement with experimental results.

The Effectiveness of Different Bracket Slot Dimensions in Orthodontic Treatment

The Effectiveness of Different Bracket Slot Dimensions in Orthodontic Treatment

Evaluation of Rate of Intrusion, Retraction and Amount of Periapical Root Resorption with Jayade’s Intrusion Arch versus Modified Three-piece Intrusion Arch using CBCT: A Research Protocol

Introduction: Deep bite, a common orthodontic malocclusion, necessitates timely intervention to prevent potential side-effects. If left untreated, a deep bite can lead to increased tooth wear, dental injuries, and Temporomandibular Joint (TMJ) disorders. Various treatment modalities, such as anterior teeth intrusion and posterior teeth extrusion, are employed to correct deep bite. However, selecting the optimal approach requires careful consideration of patient-specific factors and treatment objectives. While anterior teeth intrusion is effective for mild to moderate cases, posterior teeth extrusion may be preferred in severe deep bite scenarios. There are various treatment modalities for deep bite correction such as intrusion arches and mini screw implants. Jayade’s intrusion arch, detailed by A.V. Jayade in “Refined Begg for Modern Times” (2001), is an orthodontic appliance designed to correct vertical dental misalignments by intruding over-erupted anterior teeth. The modified three-piece intrusion arch is an advancement of the traditional intrusion arch technique. It incorporates three distinct segments: two lateral segments and a central segment. This design allows for greater precision and control over the intrusion forces applied to specific teeth or groups of teeth. Need of the Study: Simultaneous intrusion and retraction mechanics in orthodontic treatment are very challenging, and there is a paucity of data regarding the best modalities for achieving these with minimal root resorption. Aim: Comparative evaluation of the rate of intrusion, retraction and amount of periapical root resorption with Jayade’s intrusion arch and the modified three-piece intrusion arch using Cone Beam Computed Tomography (CBCT). Materials and Methods: The present prospective, two-arm parallel interventional study will be conducted in the Department of Orthodontics and Dentofacial Orthopaedics Outpatient Department, Sharad Pawar Dental College, Sawangi (Meghe), Wardha, Maharashtra, India, from September 2024 to February 2026. Study will involve the recruitment of 20 patients and all these patients will be divided into two groups for comparative analysis. The intervention will entail the use of the McLaughlin, Bennett and Trevisi (MBT) bracket system equipped with triple tubes on maxillary teeth, characterised by a slot dimension of 0.022 inches by 0.028 inches, as the standardised starting point for all cases. After initial alignment and leveling, and extractions as per the case, the intrusion arch will be applied. Jayade’s intrusion arch will be given in group A, while the modified threepiece intrusion arch will be given in group B. The assessment of intrusion rate, retraction rate and amount of root resorption will be conducted both prior to the initiation of intrusive and retractive forces, as well as, at intervals of two, four and six months following the application of the intrusion arches.

Investigating the Effect of Slot Dimensions in Bridge Abutments on the Scour Hole’s Depth

Investigating the Effect of Slot Dimensions in Bridge Abutments on the Scour Hole’s Depth

Dimensional accuracy, mechanical property, and optical stability of zirconia orthodontic bracket according to yttria proportions

This in vitro study evaluated comprehensively the performances of zirconia brackets with varying yttria proportions in manufacturing advanced orthodontic brackets. Three experimental groups of zirconia brackets were fabricated using yttria-stabilized zirconia (YSZ) materials with different yttria proportions—3 mol% yttria (3Y-YSZ), 4 mol% yttria (4Y-YSZ), and 5 mol% yttria (5Y-YSZ) (Tosoh Ceramic, Japan). A polycrystalline alumina ceramic bracket (3M™ Clarity™ Advanced, MBT 0.022-in. slot) was employed as the control group. Morphological properties, including slot surface structure and dimensions, were examined using scanning electron microscopy and surface profiler analysis. Manufacturing accuracy was assessed with root mean square calculations of trueness and precision. Mechanical properties were tested, encompassing static and kinetic frictional resistance (FR) and fracture strength. Optical stability was evaluated through 20,000 cycles of thermocycling and a 7-day immersion in various coloring agents. Within the limitations of this study, zirconia brackets containing 3 to 5 mol% YSZ presented enhanced reliability in terms of dimensional accuracy and demonstrated favorable optical stability. Notably, owing to its advantageous mechanical properties, the 3Y-YSZ variant showed remarkable potential as an advanced material for fabricating orthodontic brackets.

Video telescope operating monitor-assisted surgery is equivalent to conventional surgery in treatment of cervical intervertebral disc herniation in dogs.

To compare the use of the video telescope operating monitor (VITOM) and use of a conventional unassisted surgical method for treatment of cervical intervertebral disc herniation in dogs. 39 dogs with cervical intervertebral disc disease. Prospective study. Dogs were prospectively nonrandomly assigned to either the VITOM (n = 19) or conventional surgery (20) group depending on VITOM system availability. Signalment and preoperative neurologic status were recorded for all dogs. Preoperative and postoperative CT myelography was performed to compare intervertebral space location, spinal cord dimensions at the decompression level, ventral slot dimensions, and residual disc material. Surgical complications and postoperative neurologic outcomes were recorded. Data were compared between the 2 groups using fixed-effects or mixed-effects models to consider double reading of CT myelography images. No significant differences were noted between the 2 groups regarding the decompression ratio (P = .85), vertebral length body ratio (P = .13), ventral slot width ratio (P = .39), residual disc material (P = .30), and sinus bleeding (P = .12). No significant differences were found between the 2 groups regarding postoperative neurologic grade (P = .17). VITOM-assisted ventral slot decompression is equivalent to conventional surgery in treatment of cervical intervertebral disc herniation in dogs. The use of VITOM remains a good alternative to the conventional surgical method.

Evaluation of Slot Dimension Accuracy of Different Bracket Systems

Evaluation of Slot Dimension Accuracy of Different Bracket Systems

An Ultra-small Heated Area Masked Microwave Hyperthermia Therapy Scheme in Fresnel Region

This paper introduces a localized masked thermal therapy method for only the breast through the Fresnel region. A pyramidal horn antenna has been used as a hyperthermia system applicator. The antenna is fed by a Yagi array and resonates at 4.74 GHz. A metal plate with a square slot masked the breast phantom. The antenna irradiates the breast phantom for 5 and 10 minutes with input power of 10 and 20 watts (W). Thermal and specific absorption rate (SAR) distributions are studied under the same conditions for a fair comparison between masked and unmasked system performance. The square slot dimensions are altered, and their effects are studied considering the phantom heated area. Moving from unmasked to masked hyperthermia scenarios, a heated area size reduction of 99.87 % is achieved along with a very considerable SAR value reduction. The masked scenario elevates the breast temperature to 43 C∘ in a very concentrated area. The proposed system can elevate only an area of 2×2mm2 of the breast tissue to a temperature of 40 C∘ in 5 minutes, and that is a very promising result in hyperthermia therapy applications.

An Eight-Element MIMO Antenna Array for NR Application

We propose an eight-element multiple-input multiple-output (MIMO) antenna array for 5G (fifth generation) New Radio (NR) applications in the n78 (3.3–3.8 GHz) band to achieve a high data rate. In the proposed work antenna elements have rectangular slots on the ground. Microstrip lines directly feed an open slot in this design. The dimensions of the open slot are 21.5 × 4 mm (0.24 λ × 0.046 λ at 3.5 GHz) and the slot covers 19.18% of the bandwidth in the frequency band 3.3–4 GHz. The eight antenna elements are arranged in such a way that they are coupled and also achieve an excellent degree of polarization. The proposed eight-element MIMO antenna array is fabricated and measured. Across the operation band, the measured isolation of the proposed antenna is −35 dB, −18 dB, −11 dB, −50 dB, −18 dB, −30db, −11 dB, and −35 dB for S12, S15, S26, S34, S53, S56, S64, and S78 respectively. The proposed antenna design can achieve desired antenna parameters, i.e. Isolation >11 dB, total efficiency >68%, and several MIMO performance characteristics are evaluated, including envelope correlation coefficient (ECC) < 0.03, the total active reflection coefficient (TARC) is −7 dB, the diversity gain (DG) is 9.96 dB and the channel capacity losses (CCL) is less than 0.02 were measured at desired bandwidth. The radiation pattern and antenna gain are also shown in this paper. The design is suitable for 5G communication networks.

Design optimization of drone BLDC motor for delivery service applications

Drone based deliver system has emerged as a promising solution for efficient and timely delivery of goods. Designing an optimal motor for such drone is crucial to ensure safe, reliable, and efficient operation. This research mainly explores the design considerations and comparisons in the drone delivery system to bring the optimum configuration of the BLDC motor. The performance of the BLDC motor for the application of the drone delivery system, which is currently in the development stage for different companies like google, Amazon etc., and most research are more concerned about path travel by the drone and how to make it safe so that it wouldn’t collide and how it will deliver the product to the customer, but there are limited resources about the optimization of drone with respect to the drone-based delivery system. The motor selection for a drone delivery system requires careful analysis of various factors, including desired flight time, and power efficiency. Additionally, factors such as motor weight, and size must be considered to ensure an optimal balance between performance and operational efficiency, the research involves design optimization of the motor elements, such as slot dimensions, permanent magnet used, height and diameter of motor etc. Here, the characteristic of the BLDC motor willing to have are high torque, and high efficiency, to carry heavy loads with superlative efficiency. So the done with respect to motor design, i.e. optimizing stator design, rotor design, and the number of poles. And find out that the performance of the optimized design is better than the competitive design done (Parasiliti Model).

An Evaluation of the Accuracy and Precision of Ceramic Orthodontic Bracket Slot Dimensions Utilizing Micro-Computed Tomography (Micro-CT).

This study's aim is to determine the accuracy and precision of the bracket slot height in MBT 0.022″ ceramic brackets. Five brackets from 11 different systems (n = 55) were scanned using micro-computed tomography (micro-CT). The slot height was measured at the face (external) and base (internal) of the slot. Data were analyzed using a One-Sample t-Test, and a Paired t-Test. The lowest external height was seen in OrthoCare Purity® at 0.02264″ (2.9%), and the greatest in TOC Ghost Advanced® at 0.02736″ (24.4%). The lowest internal height was seen in Forestadent Glam® at 0.02020″ (-8.2%), and the greatest in TOC Ghost Advanced® at 0.2547″ (15.8%). OrthoCare Purity® measurements corresponded most closely with the expected measurements. TP InVu® was found to be the most precise bracket for external height (range = 0.00043″) and American Orthodontics 20/40® for internal height (range = 0.00028″). In assessing slot geometry, all brackets demonstrated a higher mean external slot height compared to the internal measurements at the base of the bracket. Orthodontic bracket slots are larger than expected and slot parallelism was not observed in any bracket brand tested. Similarly, slot dimensions are imprecise where two 'identical' brackets have different slot sizes. The clinician should, therefore, assume that play is most likely higher than expected.

The best method of reconditioning ceramic brackets to get an optimum shear bond strength compared with new ceramic brackets - Systematic review and meta-analysis of in vitro studies

Bracket debonding is an undesirable problem during fixed orthodontic treatment. As ceramic brackets have no flexibility, there is no change in the slot dimension. So, reconditioning a ceramic bracket can be done without compromising the quality of treatment and could be a cost-effective measure. The objective of this systematic review is to deduce and validate the best method of reconditioning ceramic bracket in order to get optimum clinical shear bond strength. Studies such as randomized controlled trials (RCTs); In vitro studies comparing different interventions with control group, cross sectional studies were included. Electronic databases such as Cochrane database, PubMed, Web of Science, Embase were searched up to July 2022. Grey literature search and cross-referencing/snowballing methods were also used. Two reviewers independently selected studies and assessed the risk of bias using amalgamation of five tools for in vitro studies. Then meta-analysis was performed using random effects model. Eleven studies were included in which ten studies were considered as good quality studies. According the meta-analysis performed, the best performance in terms of shear bond strength was of new brackets. Among the different reconditioning methods, the meta-analysis showed that the method with the closest bond strength to the new brackets was silicatisation with a mean difference of 6.35MPa (95% CI between 2.39 and 10.31) followed by sandblasting+silane application with a mean difference of 3.36MPa (95% CI between 0.3 and 6.96) compared to other methods. Due to the lack of in vivo studies, only in vitro studies were evaluated. The data available from the in vitro studies was considered to be of good quality, leading to the conclusion that the best method for reconditioning debonded ceramic brackets is silicatisation followed by sandblasting and silane application.

A dual‐layer polarisation rotating element for transmitarray designs

AbstractA transmitarray adopting dual‐layer polarisation rotating (PR) elements is proposed. The element comprises a pair of perpendicularly placed C‐shaped slots etched on the two sides of a single‐layer substrate and orthogonally rotates transmission wave polarisation with regard to the incidence. By adjusting C‐shaped slot's dimension as well as mirroring the bottom layer of the element, a 360° phase shift with a high transmission magnitude is achieved. Based on the proposed unit‐cell, a dual‐layer transmitarray composed of 529 elements is designed and developed. The experimental 1‐dB gain bandwidth and peak aperture efficiency are 13% and 44% respectively. Furthermore, sidelobe level of 20 dB and cross polarisation level of 26 dB are obtained at 10 GHz. These promising properties demonstrate the superiority of the element for transmitarray designs. In addition, this element can be also a good candidate for folded transmitarray designs.

Comparative evaluation of different debonding and reconditioning methods for orthodontic ceramic brackets regarding effectiveness for reuse : An in vitro study.

To investigate the reusability of ceramic brackets in terms of shear bond strength, friction behavior, slot dimension, fracture strength, and color stability. A total of 90conventionally debonded and 30by an Er:YAG laser debonded ceramic brackets were collected. All the used brackets were inspected under astereomicroscope at 18 ×magnification and sorted according to their adhesive remnant index (ARI). Five groups were formed (n = 10): (1)new brackets as acontrol group, (2)flamed and sandblasted, (3)flamed and acid bathed, (4)laser-reconditioned, and (5)laser-debonded brackets. The bracket groups were tested regarding different properties such as shear bond strength, friction behavior, slot size, fracture strength, and color stability. Analysis of variance (ANOVA) and nonparametric Kruskal-Wallis tests were used for statistical analysis (significance level: p < 0.05). Shear bond strength values of the acid reconditioned brackets were significantly lower (8.0 ± 3.1 MPa) compared to the control group (12.9 ± 2.9 MPa). Laser-reconditioned (32.8 ± 2.7%) and laser-debonded (30.9 ± 2.4%) brackets showed the lowest force loss due to friction (control group 38.3 ± 3.0%). No significant differences were observed between groups regarding slot size and fracture strength. All groups had color differences of [Formula: see text]< 10. Scanning electron microscope images and ARI scores indicated that most of the residues on the bracket bases were removed. All reconditioning methods yielded adequate results regarding bracket properties. Yet, focusing on the need to protect the enamel and the bracket base, laser debonding seems to be the most suitable method for reconditioning ceramic brackets.

Wideband Low-Loss Filter With Compact Size and Wide Stopband Based on Folded Planar Waveguide

In this letter, a hybrid, compact doubly slot-loaded folded ridged half-mode substrate-integrated waveguide (FRHMSIW) filter with wide bandwidth and high selectivity is presented and investigated. The low-pass and high-pass cutoff frequencies of the wideband filter can be independently controlled by adjusting the dimensions of the quasi-periodic slots and FRHMSIW sections, respectively. The dispersion curves, surface current distribution, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$E$</tex-math> </inline-formula> -field vector diagram of the proposed hybrid FRHMSIW bandpass unit are illustrated. Parametric study and loss analysis are also conducted. The footprint of the proposed filter is miniaturized due to the upper-side-slot-loaded FRHSIW transmission structure and meandered middle-layer slots. The stopband is further extended by etching I-shaped patterns on the ground layer. Finally, the filter is designed, simulated, and measured, with a wide passband between 3.86 and 8.3 GHz, a minimum insertion loss of 0.56 dB, a rejection level better than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$-$</tex-math> </inline-formula> 20 dB from 8.6 to 20.8 GHz, and an electrical size of only 0.21 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{g}^{2}$</tex-math> </inline-formula> at the center frequency.