Search Results (466)

This article examines how hybrid polypropylene fibers of three different lengths affect the mechanical and fracture properties of lightweight structural concrete with lightweight ceramic aggregate. Four mixtures were produced: a reference lightweight concrete and three fiber-reinforced variants with total dosages of 3, 6, and 9 kg/m³ in a fixed length ratio of 4:1:1. Standard tests determined the bulk density, cube compressive strength, splitting tensile strength, modulus of elasticity, and fracture parameters using a three-point bend test. Compared to the reference concrete, the fibers did not significantly change the compressive strength but consistently increased the tensile strength and energy absorption after cracking. The highest fracture energy and toughness were obtained at the highest dosage, while excessive fiber content reduced the static compressive modulus. Full article

The long-term esthetic performance of indirect restorations is closely related to the color stability and surface integrity of the restorative materials used. With the increasing use of CAD/CAM technologies, a wide range of ceramic- and resin-based materials have been developed for indirect restorative applications. These include feldspathic ceramics (VITA Mark II, VITA Zahnfabrik), hybrid ceramics (VITA Enamic, VITA Zahnfabrik), resin nanoceramic CAD/CAM blocks (Lava Ultimate, 3M), and indirect microhybrid resin composites (GC Posterior, GC Corporation). However, these materials are continuously exposed to chemical and mechanical challenges in the oral environment, such as staining from beverages and daily toothbrushing, which may compromise their optical and surface properties over time. The purpose of this in vitro study was to evaluate and compare the color change (ΔE) and surface roughness (Ra) of these materials after repeated coffee immersion and simulated toothbrushing. A total of 240 disk-shaped specimens were fabricated and subjected to three aging cycles consisting of storage in coffee or distilled water, followed by simulated toothbrushing with or without toothpaste. The color parameters were measured using a spectrophotometer according to the CIE Lab* system, surface roughness was assessed using a contact profilometer, and surface topography was qualitatively analyzed by atomic force microscopy. The results demonstrated that coffee immersion significantly increased both color change and surface roughness for all tested materials, with more pronounced effects observed in resin-based materials. Ceramic-based CAD/CAM materials (VITA Mark II and VITA Enamic) showed greater resistance to discoloration and surface degradation, whereas the resin nanoceramic material (Lava Ultimate) and the microhybrid resin composite (GC Posterior) exhibited clinically perceptible color changes and higher roughness values, particularly after toothbrushing with toothpaste. Full article

The traditional ultrasonic bonding technique for IGBT T2 copper terminals often causes physical damage to ceramic substrates, severely compromising the reliability of power modules. Meanwhile, T2 copper laser welding faces inherent challenges including low laser absorption efficiency and unstable molten pool dynamics. To address these issues, this study targets the high-quality connection of IGBT T2 copper terminals and proposes a welding solution integrating a Fiber-Diode Hybrid Laser system with galvo-scanning technology. Comparative experiments between galvo-scanning and traditional oscillation methods CNC scanning were conducted under sinusoidal and circular trajectories to explore the regulation mechanism of welding quality. The results demonstrate that CNC scanning lacks precision in thermal input control, resulting in inconsistent welding quality. Galvo-scanning enables precise modulation of laser energy distribution and molten pool behavior, effectively reducing spatter and porosity defects. It also promotes the transition from columnar grains to equiaxed grains, significantly refining the weld microstructure. Under the sinusoidal trajectory with a welding speed of 20 mm/s, the Lap-shear strength of the galvo-scanned joint reaches 277 N/mm², outperforming all CNC-scanned joints. This research proposes a non-contact welding strategy targeted at eliminating the mechanical failure mechanism associated with conventional ultrasonic bonding of ceramic substrates. It establishes the superiority of galvo-scanning for precision welding of high-reflectivity materials and lays a foundation for its potential application in new energy vehicle power modules and microelectronic packaging. Full article

Archaeological research on Santiago Island (Cape Verde) offers a strategic framework for investigating ceramic material culture shaped by Iberian and African interactions during the early modern period. This study presents first-stage results from a non-destructive archaeometric analysis of pottery fragments recovered from early colonial sites and curated at the Museu de Arqueologia in Praia. Using portable X-ray fluorescence spectroscopy (pXRF), low-fired, handmade vessels associated with African technological traditions were analysed to determine their elemental composition and potential provenance. The work also focused on sugar moulds, containers used in the refining of this product, one of the most important in Atlantic colonisation. The resulting geochemical data is compared with established reference groups from the Iberian Peninsula, Atlantic Africa, and Macaronesia. Elemental variability indicates the use of diverse clay sources and production techniques, reflecting hybrid technological practices shaped by cultural interaction and provisioning constraints. These results contribute to ongoing research within the CERIBAM (Iberian Atlantic Expansion in North Africa and Macaronesia) and Palarq-funded projects, which aim to reconstruct early colonial ceramic networks and sociotechnical dynamics. By integrating archaeometric data with archaeological and historical perspectives, this study aims to demonstrate the utility of non-invasive analytical protocols for understanding ceramic technology, intercultural exchange, and Atlantic material connectivity in early Creole formations while preserving the integrity of the collections. Full article

Powder bed fusion (PBF) is a widely adopted additive manufacturing (AM) process category that enables high-resolution fabrication across metals, polymers, ceramics, and composites. However, its inherent process complexity demands robust modeling to ensure quality, reliability, and scalability. This review provides a critical synthesis of advances in physics-based simulations, machine learning, and digital twin frameworks for PBF. We analyze progress across scales—from micro-scale melt pool dynamics and mesoscale track stability to part-scale residual stress predictions—while highlighting the growing role of hybrid physics–data-driven approaches in capturing process–structure–property (PSP) relationships. Special emphasis is given to the integration of real-time sensing, multi-scale modeling, and AI-enhanced optimization, which together form the foundation of emerging PBF digital twins. Key challenges—including computational cost, data scarcity, and model interoperability—are critically examined, alongside opportunities for scalable, interpretable, and industry-ready digital twin platforms. By outlining both the current state-of-the-art and future research priorities, this review positions digital twins as a transformative paradigm for advancing PBF toward reliable, high-quality, and industrially scalable manufacturing. Full article

The growing demand for portable and wireless electronic devices, along with the necessity to reduce reliance on non-renewable energy sources, has driven the need for energy harvesting materials. Nanocomposites, combining a polymeric matrix and a high-performance dielectric ceramic phase, are a promising solution. In such systems, the design of a hybrid matrix–filler interface is critical for achieving desired properties. Here, nanocomposites (NCs) were prepared by adding various amounts of hydrothermally synthesized BaTiO₃ (BT) nanoparticles (NPs) to polydimethysiloxane (PDMS). To investigate hybrid interfaces, NPs were used either bare or surface-functionalized with two silanes, 3-glycidyloxypropyltrimethoxysilane (GPTMS) or 2-[acetoxy(polyethyleneoxy)propyl]triethoxysilane (APEOPTES). NC films (80–100 μm thick) were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXS), and thermogravimetric analysis (TGA). Dielectric properties and breakdown strength (E_BD) were measured, and the theoretical volumetric energy density was calculated as a function of the filler loading and functionalization. The results demonstrate that hybrid interface design is pivotal for enhancing dielectric performance in NCs. APEOPTES-functionalized NPs significantly improved the dielectric response at a low filler loading (3.5%vol.), increasing permittivity from 2.8 to 7.5, E_BD from 33.8 to 42.1 kV/mm and energy density from 30 to >100 mJ/cm³. These findings underscore that designing hybrid interfaces through NP functionalization provides an effective strategy to achieve superior dielectric performance in PDMS-based NCs, retaining the advantages of the elastomeric matrix by reducing the amount of ceramic fillers. Full article

In the present study, glass/ceramic hybrid fibers were chosen as a paper matrix, which effectively balance toughness and high-temperature resistance for soot combustion applications. In order to address the issue of unevenness in the performance of paper-type catalysts caused by the differences in the dispersion behavior of glass fibers and ceramic fibers in water, a facile foam-forming technology was proposed. The obtained glass fiber/mullite composite paper with various mass ratios (1:1, 2:1, 3:1, 4:1, and 5:1) exhibit high evenness, and better high-temperature resistance than the pure glass fibers. After impregnating K-Mn active ingredients, 15K5Mn-GFF-3G1C (GF/CF = 3:1) demonstrates high tensile strength, excellent catalytic activity (T50 = 388 °C), reusability (five cycles), and high-temperature stability (800 °C, 12 h). Full article

This study aims to compare the surface roughness and fracture resistance of implant-supported permanent crowns additively manufactured using composite resins (Crowntec, VarseoSmile) versus subtractively manufactured polymer-infiltrated hybrid ceramic (VITA Enamic) at various wall thicknesses using an experimental setup as close to clinical as possible. 180 crowns were fabricated in three thicknesses (1.0, 1.5, and 2.0 mm) and cemented onto titanium abutments. Experimental groups underwent thermal aging (10,000 cycles) to simulate one year of clinical service. Surface roughness was measured via profilometry, and fracture resistance was assessed using a universal testing machine. Composite resin crowns exhibited lower surface roughness and lower fracture resistance than subtractively manufactured crowns. No significant difference in fracture resistance was found between materials at 1.0 mm (p > 0.05). However, at 1.5 and 2.0 mm, hybrid ceramic network crowns showed significantly higher resistance (p < 0.01). It was concluded that, within the limitations of this 1-year simulated study, both material-method combinations met the biological threshold for surface roughness. Regarding fracture resistance, composite resins and hybrid ceramics satisfied clinical requirements for molar bite forces only at thicknesses of 1.5 mm and above. 1.0 mm thickness may pose a risk under high occlusal loads. Full article

Using multifunctional dual-cure smart bioactive resin luting agents (DRLs) offers benefits in adhesive dentistry, but their optical stability remains a concern. Their pre-cured form is a shear-thinning structure with thixotropic gel-like behavior. The effect of their hydrophilicity and different thicknesses of nanoceramic hybrid on the final shade of milled esthetic restorations needs further investigation. This study examined how the optical function deterioration of dual-cure smart bioactive resin luting agents used to bond a CAD/CAM nano-ceramic hybrid composite would influence the restoration’s final shade at three different thicknesses. A nanoceramic hybrid composite (GD) was cut into blocks and grouped by thickness (0.8, 1.0, 1.5 mm). Ten blocks from each group were assigned to subgroups based on the DRL type: Panavia SA Universal (PN), Predicta Bioactive (PR), and ACTIVA BioACTIVE (AC). Color and whiteness changes after a 24 h/day (24 days) coffee immersion were analyzed using statistical methods (ANOVA and Tukey’s HSD for ΔE₀₀; Welch’s ANOVA and Games-Howell for ΔWI_D and ΔL*). DRL type significantly affected ΔE₀₀, ΔWI_D, and ΔL* (p < 0.001). All materials showed the least color change and optical function deterioration at a restoration thickness of 1.5 mm, which was below the acceptability threshold (AT). Despite PR’s bioactive functionality, it maintained its primary optical function with the least color change at GD thicknesses of 1.0 and 1.5 mm (p < 0.001). AC exhibited the greatest ΔE₀₀ above AT, especially at a thickness of 0.8 mm (p < 0.001). ΔL*, ΔE₀₀, and ΔWI_D varied significantly based on DRL type, GD thickness, and the interaction between DRL and thickness (p < 0.05). This suggests that although dual-cure smart DRLs containing bioactive glasses are advantageous, their optical function shifts may become more noticeable in thin, translucent restorations. Increasing the restoration thickness can help mitigate this by altering the optical pathway. Full article

Recent advances in biomaterials, immunomodulation, stem cell therapy, and biofabrication are reshaping maxillofacial surgery, shifting reconstruction paradigms toward biologically integrated and patient-specific tissue regeneration. This review provides a comprehensive synthesis of current and emerging strategies for bone and soft-tissue regeneration in the craniofacial region, with particular emphasis on bioactive ceramics, biodegradable polymers, hybrid composites, and stimuli-responsive smart materials. We further examine translational technologies such as extracellular vesicles, decellularized extracellular matrices, organoids, and 3D bioprinting, highlighting key challenges such as bioink standardization, perfusion limitations, and regulatory classification. Maxillofacial surgery is positioned for a paradigm shift toward personalized, biologically active, and clinically scalable regenerative solutions. Full article

This study examines the longitudinal shortening of clay blanks during extrusion and introduces a hybrid soft sensor framework for early prediction of ceramic roof tile performance. Targeted properties include shrinkage, water absorption, and saturation. The models integrate real-time process data collected after vacuum extrusion and pressing with clay-specific descriptors such as carbonate content and granulometry, alongside additional variables including moisture, firing temperature, and length reduction. Partial Least Squares (PLS) regression was adopted as the core method due to robustness against multicollinearity and ease of industrial integration. In contrast to complex machine learning pipelines, PLS-based soft sensors enable lightweight edge deployment without reliance on IoT infrastructure. Complementary regression and machine learning models were used to benchmark predictive accuracy and explore nonlinear effects. The results confirm reliable prediction of key performance indicators and reveal mechanistic links between extrusion-induced deformation and downstream behavior. Although developed for clay systems, the framework is generalizable and can be adapted to other traditional ceramic processes or industries seeking interpretable, locally deployable solutions for process control. Full article

This study proposes a cylindrical high-temperature-resistant fiber-optic composite sensor based on the EFPI-FBG hybrid structure for simultaneous temperature and pressure measurement, addressing the demand for high-performance monitoring in harsh environments. The sensor’s core consists of a cylindrical pressure chamber, a metal substrate, and an EFPI-FBG sensing structure fixed via resistance welding and high-temperature ceramic adhesive. The cylindrical pressure chamber converts pressure into axial deformation to modulate the EFPI cavity length, while the FBG with one end floating is exclusively used for temperature compensation, avoiding pressure interference. The EFPI cavity length exhibits a linear relationship with pressure, achieving a sensitivity of 0.171 μm/MPa and a linear correlation coefficient of 0.9986. Stable operation up to 600 °C and 20 MPa is demonstrated, with a decoupling matrix enabling accurate dual-parameter sensing. Full article

Additive manufacturing (AM) has emerged as a key enabling technology in contemporary dental manufacturing, driven by its capacity for customization, geometric complexity, and seamless integration with digital design workflows. This article presents a technology-oriented narrative review of additive manufacturing in dental implant production, focusing on dominant processing routes, material systems, and emerging research trends rather than a systematic or critical appraisal of the literature. An indicative descriptive analysis of publications indexed in the Web of Science and Scopus databases between 2014 and 2024 was used to contextualize the technological development of the field and identify major research directions. Emphasis was placed on metal powder bed fusion technologies, specifically Selective Laser Melting (SLM) and Direct Metal Laser Sintering (DMLS), which enable the fabrication of titanium implants with controlled porosity and enhanced osseointegration. Ceramic AM approaches, including SLA, DLP, and PBF, are discussed in relation to their potential for aesthetic dental restorations and customized prosthetic components. The publication trend overview indicates a growing interest in ceramic AM after 2020, an increasing focus on hybrid and functionally graded materials, and persistent challenges related to standardization and the availability of long-term clinical evidence. Key technological limitations—including manufacturing accuracy, material stability, validated metrology, and process reproducibility—are highlighted alongside emerging directions such as artificial intelligence-assisted workflows, nanostructured surface modifications, and concepts enabling accelerated or immediate clinical use of additively manufactured dental restorations. Full article

Background/Objectives: The clinical application of CAD/CAM restorative materials continues to evolve due to increasing demand for aesthetic, durable, and minimally invasive indirect restorations. Hybrid nanoceramics, such as Grandio disc (VOCO GmbH, Cuxhaven, Germany), are increasingly used in indirect restorative dentistry due to their favourable combination of mechanical strength, polishability, wear resistance, and bonding potential. One challenge associated with adhesive protocols for CAD/CAM materials lies in achieving durable bonds with resin cements. Extensive post-polymerization during fabrication reduces the number of unreacted monomers available for chemical interaction, thereby limiting the effectiveness of traditional adhesive strategies and necessitating specific surface conditioning approaches. This study aimed to evaluate, in a preliminary, non-inferential manner, the influence of several combined conditioning protocols on surface micromorphology, elemental composition, and descriptive SBS trends of a CAD/CAM hybrid nanoceramic. This work was designed as a preliminary pilot feasibility study. Due to the limited number of specimens (two discs per protocol, each providing two independent enamel bonding measurements), all bond strength outcomes were interpreted descriptively, without inferential statistical testing. This in vitro study investigated the effects of various surface conditioning protocols on the adhesive performance of CAD/CAM hybrid nanoceramics (Grandio disc, VOCO GmbH, Cuxhaven, Germany) to dental enamel. Hydrofluoric acid (HF) etching was performed to improve adhesion to indirect resin-based materials using two commercially available gels: 9.5% Porcelain Etchant (Bisco, Inc., Schaumburg, IL, USA) and 4.5% IPS Ceramic Etching Gel (Ivoclar Vivadent, Schaan, Liechtenstein), in combination with airborne-particle abrasion (APA), silanization, and universal adhesive application. HF may selectively dissolve the inorganic phase, while APA increases surface texture and micromechanical retention. However, existing literature reports inconsistent results regarding the optimal conditioning method for hybrid composites and nanoceramics, and the relationship between micromorphology, elemental surface changes, and adhesion remains insufficiently clarified. Methods: A total of ten composite specimens were subjected to five conditioning protocols combining airborne-particle abrasion with varying hydrofluoric acid (HF) concentrations and etching times. Bonding was performed using a dual-cure resin cement (BiFix QM) and evaluated by shear bond strength (SBS) testing. Surface morphology was examined through environmental scanning electron microscopy (ESEM), and elemental composition was analyzed via energy-dispersive X-ray spectroscopy (EDS). Results: indicated that dual treatment with HF and sandblasting showed descriptively higher SBS, with values ranging from 5.01 to 6.14 MPa, compared to 1.85 MPa in the sandblasting-only group. ESEM revealed that higher HF concentrations (10%) created more porous and irregular surfaces, while EDS indicated an increased fluorine presence trend and silicon reduction, indicating deeper chemical activation. However, extending HF exposure beyond 20 s did not further improve bonding, suggesting the importance of protocol optimization. Conclusions: The preliminary observations suggest a synergistic effect of mechanical and chemical conditioning on hybrid ceramic adhesion, but values should be interpreted qualitatively due to the pilot nature of the study. Manufacturer-recommended air abrasion alone may provide limited adhesion under high-stress conditions, although this requires confirmation in studies with larger sample sizes and ageing simulations. Future studies should address long-term durability and extend the comparison to other hybrid CAD/CAM materials and to other etching protocols. Full article

The consumption of energy and sports drinks is on the rise globally, exposing dental restorations to more frequent low-pH challenges, which affect degradation. This in vitro study simulated the combined effect of energy drink exposure and cyclic fatigue loading on the fatigue survival rate and flexural strength of three direct dental resin restorative materials with distinct chemistries: a bioactive ionic resin (Activa Presto), a giomer (Beautifil Flow Plus F00) and a conventional nano-hybrid composite (Tetric Ceram). Bar-shaped specimens (25 × 2 × 2 mm) were fabricated according to ISO 4049 and stored for 24 h in either distilled water or 0.2 M citric acid (pH ≈ 2.5), simulating an energy drink (n = 10/group). The samples then underwent chewing simulation (40 N, 100,000 cycles, 1.6 Hz) using a steel antagonist; surviving specimens were tested via three-point bending to determine their flexural strength. All the materials were affected by storage conditions: Activa Presto showed the lowest fatigue survival (20% in water; 0% in citric acid), Tetric N-Ceram moderate survival (40% in both solutions) and Beautifil Flow Plus F00 the highest and most stable survival (90% in water; 40% in citric acid). Among the surviving specimens, Tetric Ceram exhibited the highest flexural strength, followed by Beautifil Flow Plus F00 and then Activa Presto. Citric acid exposure and cyclic loading adversely affected the mechanical performance of all the materials within the limitations of this study. Full article