Search Results (471)

The photopolymer resins commonly utilized in stereolithography (SLA) additive manufacturing are non-renewable, brittle in nature and have low impact and thermal insulation properties, limiting their applications in sustainable and functional applications. To overcome these shortcomings, this paper introduces the initial research on the use of Polybutylene Adipate Terephthalate (PBAT), a biodegradable polymer, into SLA resins to create partially sustainable micro-composites with enhanced mechanical and thermal capabilities. PBAT micropowder was mixed with standard resin at 1, 5 and 10 wt% and 3D printed using SLA. To determine performance and interfacial morphology, mechanical testing (tensile and impact), thermal conductivity measurements and SEM fracture surface analysis were carried out. Introduction of PBAT significantly increased toughness, flexibility and the impact strength of the 1% PBAT composite stood at 168.63 J/m² with 68.69 J/m² of pure resin whereas the 10% PBAT sample was found to be 16% more efficient in thermal insulation. These findings indicate that partially replacing the photopolymer resin with biodegradable PBAT can enhance impact strength and thermal insulation while reducing the overall amount of petrochemical resin required. The article provides a new avenue of eco-friendly, high-performance photopolymer composites to facilitate sustainable additive manufacturing. Full article

This in vitro study investigated the fracture resistance of three ceramic-reinforced polymer (CRP) crowns—Cerasmart^® 270 (CE; milled), VarseoSmile Crown Plus^® (VS; 3D-printed) and the newly developed Hassawat-01 (HS; 3D-printed)—luted with cements of different elastic moduli. The principal hypothesis was that neither the CRP type nor the modulus of cement would significantly affect fracture resistance. Ninety-nine mandibular first molar resin dies were restored with 1 mm thick CE, VS, or HS crowns (n = 33 each) and luted with Maxcem Elite^®, RelyX Unicem^®, or Ketac Cem^® (n = 11 per subgroup). Occlusal cement morphology was evaluated using Micro-CT. Fracture resistance was measured using a universal testing machine. Crowns luted with Maxcem or RelyX withstood forces >2000 N without visible failure. Ketac-luted crowns showed reduced fracture resistance. CE-Ketac fractured in 4 of 11 specimens. VS-Ketac exhibited cracks or complete fractures (1795.2 ± 156.7 N), whereas HS-Ketac showed only superficial cracking (1732.6 ± 127.3 N). CRP crowns luted with lower-modulus resin cements demonstrated superior fracture resistance compared with those luted with glass-ionomer. VS exhibited both cracking and occasional complete fractures, whereas HS exhibited only surface cracking. All materials withstood loads greater than typical masticatory forces, supporting HS as a promising alternative within the CRP. Full article

Additive manufacturing is increasingly integrated into dental technology, yet the mechanical performance of 3D-printed denture base resins remains strongly influenced by printing orientation and post-curing duration. This study evaluated the combined effect of three printing orientations (0°, 45°, 90°) and three post-curing times (30, 45, 60 min) on the flexural strength and surface microhardness of a denture base resin. Specimens designed in Blender and fabricated using NextDent Denture 3D+ resin were subjected to three-point bending tests (n = 5 per group) and Vickers microhardness measurements (n = 10 per group). One-way ANOVA assessed main and interaction effects. Printing orientation had a significant influence on flexural strength, with horizontally printed specimens exhibiting the highest values, whereas vertically printed specimens were consistently weaker. Post-curing time did not significantly affect flexural strength within any orientation. In contrast, microhardness increased progressively with longer post-curing durations, regardless of orientation, indicating continued surface polymerisation. Because flexural strength and hardness responded differently to curing duration, no single post-curing time was universally optimal; however, 0° printing consistently produced the strongest specimens for this resin–printer system. This trade-off is clinically relevant, because dentures require high flexural strength to resist fracture and sufficient hardness to minimise wear. Full article

This study investigates the Mode II fracture behavior of bamboo–coir–rubber (BCR) hybrid composite panels developed as sustainable alternatives for wood-based panels used in structural applications. The composites were fabricated using alternating bamboo and coir layers within a polypropylene (PP) thermoplastic matrix, with styrene–butadiene rubber (SBR) incorporated as an additive at 0–30 wt.% to enhance interlaminar toughness. Commercial structural plywood was tested as the benchmark. Mode II interlaminar fracture toughness (G_IIc) was evaluated using the ASTM D7905 End-Notched Flexure (ENF) test, supported by optical monitoring to study crack monitoring and Scanning Electron Microscopy (SEM) for microstructural interpretation. Results demonstrated a steady increase in G_IIc from 1.26 kJ/m² for unmodified laminates to a maximum of 1.98 kJ/m² at 30% SBR, representing a 60% improvement over the baseline and nearly double the toughness of plywood (0.7–0.9 kJ/m²). The optimum performance was obtained at 20–25 wt.% SBR, where the laminated retained approximately 85–90% of their initial flexural modulus while exhibiting enhanced energy absorption. Increasing the initial notch ratio (a₀/L) from 0.2 to 0.4 caused a reduction of 20% in G_IIc and a twofold rise in compliance, highlighting the geometric sensitivity of shear fracture to the remaining ligament. Analysis of Variance (ANOVA) confirmed that the increase in G_IIc for the 20–25% SBR laminates relative to plywood and the unmodified composite is significant at p < 0.05. SEM observations revealed rubber-particle cavitation, matrix shear yielding, and coir–fiber bridging as the dominant toughening mechanisms responsible for the transition from abrupt to stable delamination. The measured toughness levels (1.5–2.0 kJ/m²) position the BCR panels within the functional range required for reusable formwork, interior partitions, and transport flooring. The combination of renewable bamboo and coir with a thermoplastic PP matrix and rubber modification hence offers a formaldehyde-free alternative to conventional plywood for shear-dominated applications. Full article

Background: Androgen deprivation therapy (ADT) is a fundamental component of treatment for metastatic hormone-sensitive prostate cancer (mHSPC), but it accelerates bone mineral density loss and increases fracture risk. International guidelines recommend calcium and vitamin D supplementation, baseline dual-energy X-ray absorptiometry (DXA), and antiresorptive therapy in patients with osteoporosis. Methods: We conducted a retrospective review of 156 mHSPC patients treated with ADT at a tertiary hospital between January 2022 and December 2024. We assessed adherence to guideline-recommended bone health measures. Collected variables included age, ADT duration, calcium/vitamin D supplementation, DXA testing, antiresorptive treatment, and fracture events. Exploratory stratified analyses were performed, and proportions were reported with 95% confidence intervals (CIs). Results: Calcium/vitamin D supplementation was prescribed in 50.6% of patients (95% CI: 42.9–58.4), baseline DXA was performed in 12.8% (95% CI: 8.5–18.9), and denosumab was administered in 5.1% of the cohort (95% CI: 2.6–9.8). The median follow-up was 23 months, with a fracture incidence of 0.67 events per 100 person-years. Stratified analyses showed lower adherence in older patients, those with prolonged ADT exposure, and those with high metastatic burden. Conclusions: Adherence to guideline-recommended bone health measures in patients with mHSPC receiving ADT was markedly suboptimal. These findings underscore the need to implement standardized institutional protocols to ensure systematic supplementation, routine DXA monitoring, and appropriate antiresorptive therapy. Full article

The WieZhou12 oilfield (also known as WZ12 oilfield, the same below) is in urgent need of development using large-scale volumetric fracturing technology since it is a typical complex fault-block oilfield with low porosity, low permeability, and no natural production capacity. To study the fracturing measures with surfactants in offshore oilfields like WZ12, the surfactant fracturing fluid types were experimentally selected based on their effect of decreasing interfacial tension and enhancing matrix wettability. The water cut law and oil displacement efficiency in displacement experiments were also analyzed, according to surfactant type and fluid characteristics. Next, using the numerical simulation software CMG, the study completed the integrated simulation of volumetric fracturing in the “injection–soaking–flowback” process. Finally, some critical parameters were optimized for the block model, including the quantity of injected fluids, the soaking time, and the rate of fluid flowback. The results showed that the most suitable surfactant was 0.5% ammonium lauryl polyether sulfate (ALES), which had a low interfacial tension of 1.7 × 10⁻² mN/m, a contact angle of 20.071° with the core, and a 52% oil displacement efficiency. From the simulations, the suggested production parameters for energy storage fracturing are as follows: a daily injection volume of 600 m³/d, a soaking time of 25 days post fracturing, and a fluid production rate of 270 m³/d. The findings of this study establish a significant theoretical foundation for optimizing surfactant type and provide construction advice for the integrated measure of fracturing, well shut-in, and production in offshore oilfields. Full article

To address the challenges of strong heterogeneity and poor crude oil mobility in tight conglomerate reservoirs of the Mahu Oilfield, this study systematically evaluated the effects of different surfactants on wettability alteration, spontaneous imbibition, and relative permeability through high-temperature/high-pressure spontaneous imbibition experiments, online Nuclear Magnetic Resonance (NMR) monitoring, and relative permeability measurements. Core samples from the Jinlong and Madong areas (porosity: 5.98–17.55%; permeability: 0.005–0.148 mD) were characterized alongside X-Ray Diffraction (XRD) data (clay mineral content: 22–35.7%) to compare the performance of anionic, cationic, nonionic, and biosurfactants. The results indicated that the nonionic surfactant AEO-2 (Fatty Alcohol Polyoxyethylene Ether) (0.2% concentration) at 80 °C exhibited optimal performance, achieving the following results: 1. a reduction in wettability contact angles by 80–90° (transitioning from oil-wet to water-wet); 2. a decrease in interfacial tension to 0.64 mN/m; 3. an imbibition recovery rate of 40.14%—5 to 10 percentage points higher than conventional fracturing fluids. NMR data revealed that nanopores (<50 nm) contributed 75.36% of the total recovery, serving as the primary channels for oil mobilization. Relative permeability tests confirmed that AEO-2 reduced residual oil saturation by 6.21–6.38%, significantly improving fluid flow in highly heterogeneous reservoirs. Mechanistic analysis highlighted that the synergy between wettability reversal and interfacial tension reduction was the key driver of recovery enhancement. This study provides a theoretical foundation and practical solutions for the efficient development of tight conglomerate reservoirs. Full article

Biocomposites based on natural fibres represent a promising solution for the circular economy. The aim of this study was to develop and characterise a biodegradable composite based on sheep wool from herds raised in the Kyrgyz Republic and polylactide (PLA 4032D). Composite samples with a wool–PLA ratio of 50:50 were fabricated by thermoforming at a temperature of 168 °C for 30 s (n = 10). Mechanical properties tests were performed (PN-EN ISO 604—compression tests), for impact resistance (Charpy method), differential scanning calorimetry (DSC), and measurements of density and thermal conductivity. Biodegradation samples were subjected to enriched soil conditions for 6 weeks in two variants (with and without irrigation). The results showed that the addition of sheep wool to the PLA matrix significantly increased compressive strength (23.56 ± 5.23 MPa) and impact energy absorption (226.2 ± 23.8 kJ/m²) compared to neat PLA. After biodegradation, a 59% reduction in compressive strength was observed while maintaining an increase in fracture energy, suggesting a change in the failure mechanism. The density (0.27 ± 0.02 g/cm³) and the thermal conductivity (0.127 W/m·K) comparable to polymer foams indicate potential for thermal insulation applications. Microscopy and DSC analysis confirmed complete biodegradation under soil conditions. The developed biocomposite from Kyrgyz sheep wool demonstrates the potential for valorisation of local fibrous waste for biodegradable materials with functional insulation properties. Full article

Background: Postmenopausal osteoporosis (PMO) is a major cause of fragility fractures worldwide. While exercise and calcium/vitamin D are standard preventive measures, the synergistic effects of their combined use on bone mineral density (BMD) remain unclear. Methods: We systematically searched eight databases through October 2025 and synthesized data using Review Manager version 5.4. Subgroup, sensitivity, and meta-regression analyses were conducted to examine heterogeneity and test the robustness of results. Risk of bias was assessed using the Cochrane RoB 2.0 tool, and the certainty of evidence was graded with the GRADE framework. Results: 13 RCTs involving postmenopausal women were included. Compared with calcium and vitamin D supplementation alone, combined interventions significantly increased lumbar spine (SMD = 0.31, 95% CI [0.06, 0.55]) and femoral neck BMD (SMD = 0.47, 95% CI [0.09, 0.84]), with consistent but nonsignificant trends at other skeletal sites. Subgroup analyses showed that whole-body vibration produced the greatest and most consistent benefits at both sites, while mind–body or traditional Chinese exercises (e.g., Baduanjin) significantly improved lumbar spine BMD. Shorter interventions (≤6 months) yielded greater gains in BMD, whereas longer durations provided no additional advantage. Conclusions: Exercise combined with calcium and vitamin D supplementation effectively improves bone mineral density in postmenopausal women, especially at the lumbar spine and femoral neck. Whole-body vibration and mind–body exercises show the greatest benefits, with short-term interventions proving most effective. This combined approach offers a practical, evidence-based strategy to preserve skeletal health in aging women. Full article

The main role of panoramic radiography lies in its rapid screening capability and its ability to detect and identify bone lesions, pathologies, and tooth-bearing structures. Since panoramic radiographs are widely used, they provide a good view of the jaw bones, maxillary sinus, and temporomandibular area. However, their major limitation is the reduced ability to accurately assess bone conditions, particularly in evaluating cortical integrity or identifying subtle, nondisplaced, or greenstick-type fracture lines. Other limitations include the presence of artifacts, image distortion, magnification variability, and high sensitivity to patient and film positioning, all of which can compromise image quality and diagnostic confidence. This 2D imaging method is still used worldwide, especially by dentists; however, this type of radiograph can be unpredictable due to structural superimposition and reduced ability to clearly establish, measure, and verify the precise dimensions, boundaries, and areas occupied by selected lesions. Many patients undergo panoramic imaging to assess possible mandibular fractures after trauma or following the removal of cysts, tumors, or impacted teeth. In most cases, the occurrence of a fracture without displacement can be misjudged, omitted, or underestimated. In such cases, either cone-beam computed tomography is performed or a detailed clinical examination before or during surgery, followed by intraoperative assessment, helps identify a possible fracture line, bone bending, mandibular instability, or the potential need for simultaneous prophylactic plating during dental procedures or the use of maxillomandibular fixation. This paper presents the author’s own experience regarding the limitations of panoramic radiographs in estimating bone condition and detecting fracture lines. Therefore, it is essential to highlight the role of prophylactic (preventive) mandibular plating (PMP) or fixation and to clarify when it should be considered. Full article

Three-dimensional (3D) printing enables accurate implant pre-shaping in orbital reconstruction but is costly and time-consuming. Naked-eye stereoscopic displays (NEDs) enable virtual implant modeling without fabrication. This study aimed to compare the reproducibility and accuracy of NED-based virtual reality (VR) pre-shaping with conventional 3D-printed models. Two surgeons pre-shaped implants for 11 unilateral orbital floor fractures using both 3D-printed and NED-based VR models with identical computed tomography data. The depth, area, and axis dimensions were measured, and reproducibility and agreement were assessed using intraclass correlation coefficients (ICCs), Bland–Altman analysis, and shape similarity metrics—Hausdorff distance (HD) and root mean square error (RMSE). Intra-rater ICCs were ≥0.80 for all parameters except depth in the VR model. The HD and RMSE reveal no significant differences between 3D (2.64 ± 0.85 mm; 1.02 ± 0.42 mm) and VR (3.14 ± 1.18 mm; 1.24 ± 0.53 mm). Inter-rater ICCs were ≥0.80 for the area and axes in both modalities, while depth remained low. Between modalities, no significant differences were found; HD and RMSE were 2.95 ± 0.94 mm and 1.28 ± 0.49 mm. The NED-based VR pre-shaping achieved reproducibility and dimensional agreement comparable to 3D printing, suggesting a feasible cost- and time-efficient alternative for orbital reconstruction. These preliminary findings suggest that NED-based preshaping may be feasible; however, larger studies are required to confirm whether VR can achieve performance comparable to 3D-printed models. Full article

Zygomaticomaxillary complex (ZMC) fractures are among the most common midfacial injuries, with significant implications for both function and facial esthetics. Optimal management requires restoring the normal anatomical alignment and symmetry of the zygomatic region to prevent long-term deformity and functional deficits. However, the decision-making surrounding surgical intervention, particularly in isolated ZMC fractures with moderate displacement, remains nuanced. This review discusses contemporary surgical approaches for isolated ZMC fractures and examines how objective morphometric analysis can guide critical decisions such as the timing of surgery, choice of surgical approach, and extent of fixation. Conventional assessment tools like computed tomography (CT), cephalometric measurements, and intraoperative imaging provide foundational data on fracture anatomy. Emerging technologies, including three-dimensional (3D) photogrammetry, stereophotogrammetry, artificial intelligence (AI)-based symmetry analysis, and surgical navigation systems, offer advanced means to quantify facial symmetry and bone alignment. By integrating these objective metrics into clinical practice, surgeons can enhance preoperative planning and postoperative outcome evaluation, with a particular focus on achieving facial symmetry for optimal esthetic and functional results. We also outline clinical decision-making frameworks that incorporate quantitative measurements, and we discuss current limitations, future directions, and the potential for standardizing protocols in the management of ZMC fractures. Full article

Type 2 diabetes (T2D) is associated with normal or higher bone mineral density (BMD), but there is a higher fracture rate. Hypoglycaemia does not affect BMD but may cause fractures directly through falls and may affect bone cellular metabolism. We examined circulating bone marker proteins (BMPs) in response to induced hypoglycaemia in T2D versus controls. A prospective exploratory parallel study design was conducted in T2D patients (n = 23) and healthy controls (n = 23) who underwent blood SOMAscan proteomic analysis of bone biomarkers at baseline, hypoglycaemia, and post-hypoglycaemia time points. Unadjusted repeated measures linear mixed modeling was used for analysis. Linear mixed modeling of the proteins showed that the way most BMPs changed over time did not differ between groups. At baseline, Dickkopf-related protein 1 (DKK1), cathepsin A, cathepsin S, and cathepsin Z were increased in T2D versus controls (p < 0.05), whilst fibroblast growth factor 23 (FGF23) was lower in T2D versus controls (p ≤ 0.05). Following hypoglycemia, transient changes from baseline occurred in DKK1, cathepsin A, cathepsin G, cathepsin H, cathepsin S, cathepsin Z, parathyroid hormone (PTH), Sphingosine kinase 1 and 2 (SPK1/2), and interleukin-1 beta (IL1 beta) over the post-hypoglycaemia time course. There was decreased cathepsin S in T2D from baseline to 24 h compared to the control group, and increased cathepsin Z at 24 h for both groups overall compared to baseline (p < 0.05). Baseline-raised cathepsins (A, S, Z) in T2D may enhance osteoclastic resorption, whilst raised DKK1 could inhibit osteoblast differentiation and suppress bone formation. Hypothetically, this may lead to a decline in bone quality through a resorption-enhanced, low bone formation imbalance. The effects of hypoglycaemia on bone physiology appear to extend significantly beyond the initial insult, as seen for cathepsin S and Z, which differed at 24 h compared to baseline. Full article

Inorganic gap filling technology is an effective method to improve reliability and heterogeneous integration density in 2.5D and 3D integration. It uses plasma-enhanced chemical vapor deposition (PECVD) to deposit silicon dioxide (SiO₂) filler layers in gaps between chiplets. This technology is used to replace the Epoxy Mold Compound (EMC) commonly used in traditional packaging. However, as an inorganic filling material, SiO₂ poses reliability challenges such as cracking and peeling during or after deposition. Furthermore, there lacks quantitative characterization and modeling of the microscale mechanical properties, thermal stress distribution, and fracture failure risk in the filler layer. By combining nanoindentation technology with three-point bending tests, this study reports a comprehensive characterization route for quantitative characterization of mechanical behavior of the filler. A finite element method (FEM) model was also established to predict the thermomechanical reliability of the gap filling process. Raman spectroscopy measured data confirm the model’s reliable predictive ability. The results reveal the impact of filler thickness on the stress. The microscale SiO₂ mechanical characterization method and the thermal stress and fracture risk FEM prediction model in this study not only address the limitations of traditional testing and simulation but also provide support for process optimization and structural design of gap filling in high-density 2.5D/3D packaging. This work promotes the understanding of inorganic filling process reliability in chiplet integration. Full article

04Cr13Ni5Mo martensitic stainless steel is extremely sensitive to forging temperature and is prone to generating extremely large cracks, which leads to the failure of forging. Therefore, high-temperature tensile tests were performed on 04Cr13Ni5Mo martensitic stainless steel using a Gleeble-1500D thermo-mechanical simulator to investigate its damage mechanisms. The tests covered a temperature range of 950–1200 °C and strain rates of 0.001–1 s⁻¹. The high-temperature damage behavior and tissue evolution law at high temperatures were studied by means of EBSD, TEM, etc. Secondly, two high-temperature damage models of 04Cr13Ni5Mo, namely Normalized Cockcroft and Latham (NCL) and Oyane, were established by combining optimization algorithm and finite element simulation. Then, the two high-temperature damage models were integrated into the Forge^®NxT 3.2 finite element software. Simulated thermal tensile tests were conducted on 04Cr13Ni5Mo at temperatures from 950 to 1200 °C, strain rates from 0.001 to 1 s⁻¹. A comparison was made between the predicted and experimentally measured fracture displacements of the tensile specimens. The calculated correlation coefficients (R) were 0.995 and 0.991, respectively. It was determined that the NCL model has better simulation accuracy for predicting the forging cracks of 04Cr13Ni5Mo. The reliability of the finite element method for predicting forging crack defects in 04Cr13Ni5Mo forgings was established. Full article