Search Results (222)

Background: Prosthetic cementation using the biologically oriented preparation technique (BOPT) presents challenges in removing excess cement from the gingival sulcus, due to the absence of a finishing line and the impossibility of using absolute isolation with a rubber dam. This study aimed to evaluate the effectiveness of relative isolation using polytetrafluoroethylene (PTFE) tape in reducing cement retention during BOPT cementation. Methods: Fifteen 3D-printed resin models were created from an intraoral scan of a patient restored with BOPT in both upper central incisors. Each model included removable gingiva. Splinted polymethylmethacrylate (PMMA) provisional crowns were fabricated and cemented with temporary cement. One central incisor was isolated with PTFE (0.1 mm or 0.2 mm), while the contralateral tooth was left unisolated as a control. After debonding, digital scanning and volumetric analysis using root mean square (RMS) deviation were performed to quantify retained cement. Paired t-tests were applied to compare groups. Results: The mean RMS for the PTFE group was 0.1248 ± 0.0519 mm, compared to 0.1973 ± 0.0361 mm in the non-isolated group (p < 0.001). No significant difference was found between PTFE thicknesses of 0.1 mm and 0.2 mm (p = 0.388). Conclusions: PTFE tape is effective for relative isolation when rubber dam placement is not feasible in BOPT restorations. Further clinical studies are recommended to confirm these findings in vivo. Full article

Objective: This study aims to evaluate the stress distribution on endodontically treated anterior teeth restored using different restorative materials and different post lengths versus endocrowns employing finite element analysis (FEA). Methods: An extracted human central incisor tooth with a fully formed apex was scanned using high-resolution cone beam computed tomography (CBCT) to generate 3D finite element models. Six models of restorations of badly destructed central incisor were grouped according to the type of ceramic material and post length versus endocrown restorations. Group V-L: Vita Enamic, long post (10 mm intra-radicular), Group C-L: Celtra Duo, long post (10 mm intra-radicular), Group V-Sh: Vita Enamic, short post (3 mm intra-radicular), Group C-Sh: Celtra Duo, short post (3 mm intra-radicular), Group V-E: Vita Enamic endocrown (3 mm intra-radicular), and Group C-E: Celtra Duo endocrown (3 mm intra-radicular). A static load of 200 N was applied to the palatal surface at a 45 degree angle to the tooth’s long axis. The maximum equivalent von Mises stress and maximum principal stress were analyzed at four locations: the finish line, coronal third of the root (12 mm from the apex), middle third of the root (8 mm from the apex), and apical third of the root (4 mm from the apex). Results: Group C-L exhibited the highest maximum VM stress and PS at the finish line, in addition to the highest maximum VM stress and PS at the root apical third, while group C-Sh reported the least maximum VM stress at the root apical third among the groups. All Celtra Duo groups reported higher maximum VM stress than the corresponding groups of Vita Enamic at the finish line and root coronal thirds. However, at the root middle and apical thirds, both materials recorded similar stresses. Conclusions: Short posts and Vita Enamic endocrowns showed minimal stress, especially at the finish line, while long posts increased stress and fracture risk. The findings support conservative restorations without posts, although clinical validation is needed to confirm their long-term effectiveness and safety. Full article

This study proposes a sustainable method to convert high-silicon lead-zinc tailings (HS-LZT) into lightweight and high-strength ceramsite, aiming to address the issues of solid waste management and resource efficiency by using HS-LZT and kaolin as the main raw materials and silicon carbide (SiC) as the pore-forming agent. A sintering process was employed to prepare lightweight, high-strength ceramsite. X-ray diffraction (XRD), X-ray fluorescence (XRF), Thermogravimetric-differential scanning calorimetry (TG-DSC), and inductively coupled plasma optical emission spectrometer (ICP-OES) were used to analyze the physical composition and physical and chemical properties of the raw materials. The influence of raw material ratios, SiC content, sintering temperature, and sintering time on ceramsite properties was investigated, and the microstructure of the optimal finished ceramsite was analyzed. The results show that under optimal preparation conditions (70% [by mass percentage] of HS-LZT, 30% [by mass percentage] of kaolin, with an addition of 0.5% [by mass percentage] of SiC, a sintering temperature of 1200 °C, and a sintering time of 20 min), the LZT ceramsite achieved a compressive strength of 11.39 MPa, a bulk density of 724 kg/m³, and a 1 h water absorption rate of 4.82%. The leaching content of Pb and Zn of the sintered ceramsite samples is far less than the limit values of hazardous components in the leachate specified in the relevant standard. This study provides a potential pathway for the reduction, recycling, and environmentally sound utilization of HS-LZT, which is in line with the sustainable development concept of “treating waste with waste.” Full article

Surface roughness plays a vital role in determining surface integrity and function. Surface irregularities or reduced quality near the surface can contribute to material failure. Surface roughness is considered a crucial factor in estimating the fatigue life of structures welded by FSW. This study attempts to provide a deeper understanding of the nature of the surface formation and roughness of aluminum joints during FSW processes. In order to form more efficient joints, the frictional temperature generated was monitored until reaching 450 °C, where the transverse movement of the tool and the joint welding began. Hardness and tensile tests showed that the formed joints were good, which paved the way for more reliable surface roughness measurements. The surface roughness of the weld joint was measured along the weld line at three symmetrical levels using welding parameters that included a rotational speed of 1250 rpm, a welding speed of 71 mm/min, and a tilt angle of 1.5°. The average hardness in the stir zone was measured at 64 HV, compared to 50 HV in the base material, indicating a strengthening effect induced by the welding process. In terms of tensile strength, the FSW joint exhibited a maximum force of 2.759 kN. Average roughness (Rz), arithmetic center roughness (Ra), and maximum peak-to-valley height (Rt) were measured. The results showed that along the weld line and at all levels, the roughness coefficients (Rz, Ra, and Rt) gradually increased from the beginning of the weld line to its end. The roughness Rz varies from start to finish, ranging between 9.84 μm and 16.87 μm on the RS and 8.77 μm and 13.98 μm on the AS, leveling off slightly toward the end as the heat input stabilizes. The obtained surface roughness and mechanical properties can give an in-depth understanding of the joint surface forming and increase the ability to overcome cracks and defects. Consequently, this approach, using adaptive thresholding image processing coupled with grayscale histogram analysis, yielded significant understanding of the FSW joint’s surface texture. Full article

The aim of this study was to compare the dimensional accuracy of vinyl polysiloxane impressions differing in terms of curing time (regular-setting (RS) or fast-setting (FS)) in combination with different tray materials (metal (M) and plastic (P)). A typodont reference model simulated a partially edentulous maxilla. Reference points were given by center points of either precision balls welded to specific teeth or finishing-line centers of prepared teeth. These reference points enabled the detection of dimensional deviations between the digitized reference and the scans of the models achieved from the study impressions. Twenty impressions were made for each of the following four test groups: RS-M, RS-P, FS-M and FS-P. Global scan data accuracy was measured by distance and tooth axis deviations from the reference, while local accuracy was determined based on the trueness and precision of the abutment tooth surfaces. Statistical analysis was conducted using ANOVA accompanied by pairwise Tukey post hoc tests (α = 0.05). Most of the distances tended to be underestimated. Global accuracy was favorable; even for long distances, the mean absolute distance deviations were < 100 µm. Local accuracy was excellent for all test groups, with trueness ≤ 11 µm and precision ≤ 9 µm. Within the limitations of this study, all impression and tray materials were suitable to fabricate models with clinically acceptable accuracy. Full article

Background: Modern dentistry demands accurate finish line designs for abutments. CAD/CAM systems enable the fabrication of thin prosthetic structures to fulfill this requirement. The aim of this study is to research the mechanical resistance of customized implant abutments with different types of marginal design in laboratory environment. The null hypothesis is there is no difference in fatigue loading and compression strength in custom implant abutments with chamfer or vertical marginal design. Methods: The study model includes 60 specimens of implant suprastructures, organized into four test groups, by the margin design and used material: Group A—suprastructures, made of monolithic zirconia implant crown and titanium custom abutment with vertical marginal design; Group B—suprastructures, monolithic lithium disilicate implant crown and titanium custom abutment with vertical marginal design; Group C—suprastructures, made of monolithic zirconia implant crown and titanium custom abutment with chamfer marginal design; and Group D—suprastructures, made of monolithic lithium disilicate implant crown and titanium custom abutment with chamfer marginal design. All samples were subjected to fatigue loading test in chewing Simulator CS-4 (SD-Mechatronik, Westerham, Germany) for 1250,000 cycles, at a frequency of 2 Hz. The specimens, which survived, was conducted to compressive strength test in universal testing machine Instron M 1185 (Instron, Norwood, MA, USA). Results: The results analysis highlighted Group A as the most resistant to compressive forces (4411 MPa). Group D was with lowest values (1864 MPa)—twice than Group A. Group B (3314 MPa) had lower results than Group A, but higher than Groups C (3130 MPa) and D. Conclusion: Compression strength significantly depends on the choice of marginal design of implant abutments. Vertical margin design has better performance, that chamfer one. Full article

Humans are in constant contact with clothing and textiles throughout their lives, which can expose them to chemicals present in these materials. Chemicals used in fiber production and in material processing can be absorbed through the skin, ingested, or inhaled, causing allergic reactions. Advancements in modern textiles have made them more versatile and functional for a variety of applications, resulting in the use of more chemicals. Regarding the textile industry, several studies have focused on the environmental impact of its effluents and dyes, and, more recently, several studies have focused on textile waste impact in general. Nevertheless, few studies have been carried out on human cytotoxicity, and very little is known about the dangers of long-term use of textiles. The aim of this work was to review the literature to understand what has been done in the field of textile cytotoxicity. In addition, this work also highlights the existing gap regarding regulation and standardized tests for the analysis of everyday clothing. There is an urgent need to establish regulations and standardize testing protocols to assess the potential cytotoxic effects that may arise from finished textile products before they are marketed, in order to guarantee consumer safety. Full article

This study aimed to evaluate the effects of no tail docking on the performance, health, and behavior of piglets raised under commercial conditions in Brazil. The study included 768 weaned piglets from the Pietrain synthetic line, randomly divided into two groups: DT = the final third part of the tail-docked (n = 384) and NTD = non-tail-docked (n = 384). Tail docking was performed on day two using an electrocautery clipper for piglets from the DT group, and both groups were subjected to standard environmental enrichment with branched chains. In cases of tail biting, a contingency plan was adopted to mitigate this problem by enriching the pen with a sisal rope. Behavioral measurements were performed using scan sampling. Tail biting, reactivity to humans, and health were assessed using a methodology adapted from the Welfare Quality Protocol^®. The piglets were weighed at 140 days of age and inspected according to the parameters established by the Pig Genealogical Registration Service to be used as reproduction animals. The off-test rate was calculated based on the total number of piglets approved for animal use relative to the total number evaluated. During the nursery stage, the NDT piglets showed a trend toward significance (p = 0.07) toward a higher occurrence of tail biting than the DT piglets and exhibited a higher incidence of severe lesions. They also engaged more frequently (p < 0.05) in exploratory behavior, interacting with branched chains and sisal rope, than the DT piglets. During the finishing phase, tail biting was observed only in the NDT piglets (p = 0.001). The NDT piglets that did not require the contingency plan exhibited lower fear responses (p = 0.02) during human interactions in the nursery phase than the DT piglets. Conversely, the NDT piglets that required a contingency plan showed higher fear levels (p < 0.001). Productivity performance was not affected (p > 0.05), and new cases of tail biting ceased after the contingency plan was implemented. The number of animals that died or were removed did not differ between the treatments (p > 0.05). In conclusion, managing piglets with intact tails on commercial farms presents a significant welfare challenge. By contrast, docking the final third of the tail, in accordance with regulations, was associated with fewer negative welfare outcomes, even when best management practices were applied. Full article

Laser powder bed fusion (L-PBF) has become a highly viable method for manufacturing metal structural components for a variety of industries. Despite many attractive qualities, the rough surfaces of L-PBF components often necessitates post-processing treatments to improve the surface finish. Furthermore, heat treatments are generally necessary to control the microstructure and properties of L-PBF components, which can impart a detrimental surface oxide layer that requires removal. In this investigation, cavitation abrasive surface finishing (CASF) was adopted for the surface treatment of Ti6Al4V components produced by L-PBF and removal of the surface oxide layer. The surface texture, residual stress, and material removal were evaluated over a range of treatment conditions and as a function of the target surface orientation. Results showed that CASF reduced the average surface roughness from the as-built condition (R_a ≈ 15 µm) to below 5 µm as well as imparted a surface compressive residual stress of up to 600 MPa. The CASF treatment removed the alpha case from direct line-of-sight surfaces under a range of treatment intensity. However, deep valleys and surfaces at large oblique angles of incidence (≥60°) proved challenging to treat uniformly. Overall, results suggest that CASF could serve as a potent alternative to chemical treatments for post-processing of L-PBF components of titanium and other metals. Further investigation is recommended for improving the process effectiveness and to characterize the fatigue performance of the treated metal. Full article

Accurate prognosis at first treatment for bovine respiratory disease (BRD) is essential for timely interventions and management decisions. This cross-sectional observational study evaluated 819 commercial beef feedyard cattle at chute-side for first BRD treatment. Logistic regression models examined potential associations between two outcomes—first treatment failure (requiring additional treatment) and unfinished treatment (due to mortality or culling)—and several explanatory variables, including sex, days on feed, bodyweight, breed, pulse oximetry, lung auscultation scores, and ultrasound lung scores (ULS) measured in the caudo-dorsal lung region. Animals that ultimately did not finish treatment were significantly more likely to present a ULS of 5 (74%) compared with those scored 1–4 (18–38%). Similarly, cattle with a ULS of 5 had a much higher probability of first treatment failure (74%) than those with scores of 1–3 (35–41%). Moreover, three or more B-lines in the ultrasound image or a “moth sign” finding were both strongly associated with increased probability of negative outcomes. These results highlight key ultrasound-based and demographic factors that serve as practical prognostic indicators for cattle at the onset of BRD treatment. Full article

Background/Objectives: Urinary incontinence (UI) is a common condition affecting women worldwide, with pelvic floor muscle training exercises (PFMT) recognized as the first-line treatment for UI. Supplementation with bioactive compounds, such as collagen and magnesium, may enhance the effectiveness of PFMT. This study aimed to evaluate the efficacy of combining a food supplement containing collagen and magnesium with PFMT in women experiencing stress (SUI), urge (UUI), or mixed (MUI) urinary incontinence. Methods: A pilot clinical trial was carried out on 44 women with stress, urge, or mixed urinary incontinence. The improvement in urinary incontinence was assessed, before and after 6 weeks (W6) of product use, by the Questionnaire for Urinary Incontinence Diagnosis (QUID) and the clinical assessment of the gynecologist. Quality of life (QoL) was assessed as a secondary endpoint. Results: At Week 6, the baseline median QUID score in the active group was significantly reduced by 64% (p < 0.001), with 76% finishing the study with a negative diagnosis for UI. In contrast, the placebo group showed a reduction in QUID score by only 10% (p < 0.001), with just 25% of participants achieving a negative diagnosis for UI. QoL statistically significantly (p < 0.001) improved by 76% in the active group, while no changes were observed in the placebo group. Conclusions: Supplementation with the (Dermoxen^® PelviPlus™/Dermoxen^® Gynable^® Urocollagen™) tested product significantly improved urinary symptoms and quality of life, demonstrating a greater effect than pelvic floor muscle training (PFMT) exercises alone. Dermoxen^® PelviPlus™/Dermoxen^® Gynable^® Urocollagen™ demonstrated efficacy across all three subtypes of UI. Full article

The interfacial bonding properties of stainless steel clad (SSC) rebars determine whether they can be widely used. In the industrial production of SSC rebars, the process of intermediate and finish rolling of the microstructure evolution, element diffusion behavior, and interfacial bonding properties of bimetallic interfaces are investigated. In this paper, 316L seamless stainless steel (SS) tube and HRB400E carbon steel (CS) bar were prepared by a vacuum oxidation-free composite round billet, and the industrial emergency stopping of SSC rebars’ hot rolling was carried out. The metallographic results showed that the thicknesses of the carburized austenite zone (CAZ) varied greatly (832–238 μm) and showed a parabolic downward trend, while the thicknesses of the decarburized ferrite zone (DFZ) varied little (85–99 μm). The elemental line scans showed that Fe and Cr had the same parabolic downward trend. The intermediate-rolling had a great influence on element diffusion, and, in S6–9, the diffusion distance of Fe and Cr decreased significantly. The diffusion distances of the elements in the intermediate-rolling back stage and finishing-rolling front stage (S9–12) were basically balanced. The elemental diffusion distances and interfacial bonding strength were not consistent. Among them, the shear strength (τ) of S13 was 410.7 MPa. Compared with ordinary rebars, the yield strength (Re) and tensile strength (Rm) of finished SSC rebars were increased by 7.05% (30.9 MPa) and 7.10% (43.0 MPa), respectively. The tensile properties exceed those of mixture effects. The paper provides a theoretical basis for the improvement of the interfacial bonding strength and optimization of the rolling process system for the industrial production of SSC rebars. Full article

Introduction: Injury and illness rates within cycling are a growing concern for riders, medical personnel, and event organisers. This study is the first to document injury and illness rates in professional cyclists throughout one competitive season including training and racing. Methods: A prospective, longitudinal study was conducted with 47 professional cyclists (30 males and 17 females) over the 2024 season (1 November 2023–31 October 2024). Injuries and illnesses were defined and recorded following the International Olympic Committee (IOC) consensus guidelines for injury reporting in sports and its cycling-specific extension. Data collection utilised a centralised online hub, integrating exposure metrics (e.g., training hours and kilometres) and medical records. All data were processed on a Macintosh computer using the Microsoft Office and R statistics packages epi tools, binom.test function, and ggplot. (V.4.3.2, R Foundation for Statistical Computing, Vienna, Austria). Ethical approval was obtained from Queens University Belfast, number MHLS 23_175. Results: Fifty-five injury events were logged, with 1.15 (±0.359) locations injured per incidence and 1.57 (±1.06) injury types per incident. The overall combined injury rate for racing was 4.14 (95% CI: 2.65–5.79) per 1000 h of exposure, with the overall combined rate for training being 1.23 (95% CI: 0.8–1.7) per 1000 h. The injury risk ratio (RR) for injury during racing and training for females was 11.10 (95% CI: 2.69–37.60), and the RR for males was 10.24 (95% CI: 3.84–43.06), both indicating there is a significantly higher risk of injury during racing compared to training. Abrasions were the most common injury type, with fractures being the most burdensome injury. The most common illness was upper respiratory, 0.63 (95% CI: 0.27–0.99) per year for males and 1.11 (95% CI: 0.64–1.59) per year for females. Saddle sores were the second most common at 0.20 (95% CI: 0.04, 0.36) per year for males and 0.08 (95% CI: 0–0.18) per year for females. Conclusions: This study provides the first comprehensive, season-long surveillance data for injuries and illnesses in male and female professional road cycling, highlighting the significant differences in injury profiles between racing and training. These results underscore the need for targeted injury prevention strategies and the establishment of a standardised injury and illness framework for professional cycling. Full article

Non-metallic inclusions (NMIs) in steel have a detrimental effect on the processing, mechanical properties, and corrosion resistance of the finished product. This is particularly evident in the case of macroscopic inclusions (>100 µm), which are rarely observed in steel castings produced using state-of-the-art technologies, whereby casting parameters are optimized towards steel cleanliness, and post-treatment steps such as vacuum arc remelting (VAR) are used, but frequently result in the rejection of the affected product. To improve production processes and develop effective countermeasures, it is essential to gain a deeper understanding of the origin and formation of NMIs. In this study, the potential of elemental and isotopic fingerprinting to trace the sources of macroscopic oxide NMIs found in VAR-treated steel ingots using SEM-EDX, inductively coupled plasma mass spectrometry (ICP-MS), laser ablation ICP-MS (LA-ICP-MS), and laser ablation multicollector ICP-MS (LA-MC-ICP-MS) were exploited. Following this approach, main and trace element content and ⁸⁷Sr/⁸⁶Sr isotope ratios were determined in two specimens of macroscopic NMIs, as well as in samples of potential source materials. The combination of the data allowed the drawing of conclusions about the processes leading to the formation of these inclusions. For both specimens, very similar results were obtained, indicating a common mechanism of formation. The inclusions were likely exogenous in origin and were primarily composed of calcium–aluminum oxides. They appeared to have undergone chemical modification during the casting and remelting process. The results indicate that particles from the refractory lining of the casting system most likely formed the macroscopic inclusions, possibly in conjunction with a second, calcium-rich material. Full article

Crude protein (CP) reduction and amino acid (AAs) supplementation is an interesting cost-reducing strategy for environmental compliance. The objective of this work is to study productive performances of heavy Duroc X (Landrace X Large white) male and female pigs during the finishing stage under a 2% CP reduction with crystalline AA supplementation. A total of 60 entire male and 60 female pigs (means ± standard deviations: 109 ± 4.9 days of age; 67.9 ± 7.18 kg of body weight) were distributed in split-sex pens (6 pigs/pen) and fed ad libitum. Two isoenergetic diets were provided (145 and 125 g CP/kg with AA supplementation, control and low-CP) during the final 42 days of finishing period. Growth performance, carcass and meat traits were evaluated. The fixed effects of dietary treatment, sex and their interaction were considered and simple least squares models used. Males were 7.25% heavier (p < 0.001) and had 16% higher average daily gains (p < 0.0001) than females in both treatments with no differences in feed intake or feed conversion ratio (p > 0.05). Nitrogen efficiency was 35% higher in low-CP males. Little difference was found for most carcass and meat traits between treatments. Males had 7–8% higher loin subcutaneous fat thickness in both dietary treatments (p = 0.011). Males and females of the low-CP diet showed higher fat and saturated fat contents than controls (p = 0.020). A 20 g/kg CP reduction with AA supplementation is an efficient strategy during the finishing phase without productivity losses in heavy Duroc sire line genotypes of both sexes. Full article