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Objectives: The study aimed to develop and evaluate in vitro a varnish containing fluoride-doped glass ceramics capable of inhibiting oral microorganisms, releasing hydroxyapatite-forming ions, and ensuring biocompatibility. Materials and methods: For the production of the experimental varnish (VE), composed of hydrogenated rosin, 10% and 20% by weight of glass ceramics with composition S53P4 (CF0) and doped with Fˉ ions (CF5 and CF10) were incorporated. The EVs were characterized by Rheology, Scanning Electron Microscopy (SEM), FTIR, ion release (fluoride and calcium ions), cytotoxicity on VERO cells, and antimicrobial effect on S. mutans, S. aureus and C. albicans and anti-biofilm effect on S. mutans. The data were analyzed by One-Way ANOVA and Kruskal–Wallis test (P = 0.05). Results: Homogeneous varnishes with good viscosity were obtained. Varnishes with 20% CF demonstrated biocompatibility and minimum inhibitory concentration (MIC) at concentrations lower than 10 mg/mL and 3.12 mg/mL, respectively, except for C. albicans. An anti-biofilm effect on S. mutans was observed for the varnishes with 20% CF. All varnishes with CF released more Fˉ than the commercial varnish, with V20CF10 standing out, which released 4 times more Fˉ ions in a quarter of the time. Conclusions: The V20CF10 varnish is a promising material for dental use in the treatment of early caries lesions, due to its biocompatibility, antimicrobial properties, and release of hydroxyapatite-forming ions. Clinical relevance. The use of a new varnish that combines antimicrobial properties with hydroxyapatite-forming ion release may prevent or halt the progression of dental caries lesions, offering greater efficacy than currently available varnishes. [ABSTRACT FROM AUTHOR]

The present work reports on the results of the synthesis and study of complex cesium lead bromide glass ceramics using classical heating and thermal plasma. The role of the substrate in the thermal plasma-assisted processes of growth has been disclosed. For reference, powder samples of these bromides were also synthesized. X-ray diffraction (XRD) revealed the presence of many material phases in all the samples except for the glass ceramics grown in a furnace using classical methods. The dominant phase was Cs4PbBr6 in most cases. However, CsPbBr3 was also present in some samples. Exotic phases such as solid Br2, metallic Cs (which dominates in one of the glass ceramic samples), and Cs4Pb9 were also observed. This indicates cesium segregation during the samples' growth and excess cesium in metallic form within the samples. The existence of CsPbBr3 quantum dots within or among the Cs4PbBr6 nanocrystals has been confirmed by photoluminescence (PL) measurements. Electron paramagnetic resonance (EPR) revealed the existence of Cs0–Cs0 dimers in a type of quantum dot undergoing a phase transition at 10 K. [ABSTRACT FROM AUTHOR]

We prepared a 1Eu2O3-13Bi2O3-12ZnO-74TeO2 glass (PG) and its glass ceramics (GC340, GC350, and GC360) and evaluated their luminescence properties for scintillators. GC340, GC350, and GC360 were obtained by heat treatment of PG for 24 h at 340, 350, and 360 ℃, respectively. Distinct luminescence peaks derived from the radiative transition between 4f levels of Eu3+ appeared in PG, GC340, GC350, and GC360 when excited by X-rays or visible light. The scintillation intensity was enhanced by increasing the heat treatment temperature of PG, whereas the quantum yield in photoluminescence was decreased by heat treatment. The results suggest that the energy transfer efficiency in the host material might be increased by heat treatment. [ABSTRACT FROM AUTHOR]

Background: Conservative dentistry introduced modern restoration designs, contributing to the greater use of partial-coverage ceramic restorations. New strong bondable ceramic materials made fabricating partial coverage ceramic restorations easier to restore the badly destructed teeth. Aim of the study: This study investigated the impact of three distinct overlay preparation designs on the marginal fit (both before and after thermal aging) and the fracture resistance of overlay restorations fabricated using advanced zirconia-reinforced lithium disilicate (ALD) CAD/CAM glass-ceramic blocks. Materials and methods: Using a standardized preparation protocol, three typodont molars were prepared to receive three different indirect overlay ceramic restoration designs. The typodont teeth were duplicated to get 27 resin dies that were randomly allocated into three groups (n = 9) based on the preparation design; group (O): a traditional overlay preparation with anatomical occlusal reduction, group (OS): anatomical occlusal reduction with circumferential shoulder finish line, and group (OG): anatomical occlusal reduction with a central groove preparation at the mid-occlusal surface. After standardized restorations fabricated following the manufacturer's guidelines, the restorations were cemented to their corresponding dies and exposed to thermal aging corresponding to 6-month clinical service. Marginal gap was measured before and after thermal aging procedure using an optical microscope. To measure fracture resistance, specimens were loaded till failure using the universal testing machine. The Kruskal Wallis test was utilized to assess data among the groups, followed by Dunn's post hoc test with Bonferroni correction. Differences in the marginal fit before and after thermal aging were evaluated using Wilcoxon Sign Rank test. Results: A statistically significant difference in marginal fit was observed between the studied groups, with a p-value of 0.032 where group OS has the lowest micro gap compared to group OG and group O. The fracture resistance group (O) recorded the highest fracture resistance with a statistically significant difference between the studied groups at p value = 0.043. Conclusions: Adjusting the tooth preparation significantly influenced both the fracture resistance load and the marginal fit observed for advanced zirconia-reinforced lithium disilicate glass-ceramic (ALD) overlays. [ABSTRACT FROM AUTHOR]

Future alternatives for an electrode lithium borate-based glass–ceramic (GC) has been developed for rechargeable lithium-ion batteries. The composition of the GC is xNiO-(0.20-x)MnO2-0.80(Li2S:B2O3), where x varies from 0.10, 0.13, 0.15, and 0.16. The GC were fabricated using the melt-quenching technique. The nature of the GC was determined using XRD examinations. The SEM-EDS analysis indicates the presence along with the distribution of components in the plate glasses. The battery charge/discharge tests showed that the 0.16NiO-0.04MnO2-0.8(Li2S:B2O3) (0.16Ni-0.04Mn) glass-ceramics exhibited a potential range of 0.8–1.1 V and a discharge capacity of 70 mAh.g−1 during the first cycle. Additionally, these GC demonstrated excellent cycling stability for over 100 cycles. As the same time, electrical impedance spectroscopy (EIS) measurements showed that the Li diffusion coefficient in 0.16Ni-0.04Mn GC was found to be 0.34 × 10−10 and 0.75 × 10−11 cm2.s−1 for before and after cycling, which is smaller than 0.10Ni-0.10Mn. Synchrotron-based XANES highlighted the oxidation state of Ni2+, as well as the mixing of Mn2+/3+ and S−1. The addition of Ni and Mn into the lithium-sulfur borate glass system has improved its electrochemical characteristics, making it a very interesting and economically viable option for energy storage technology electrodes.

Abstract Background Lithium disilicate occlusal veneers are popular for minimally invasive posterior teeth restoration. The aim of this study was to compare the fatigue resistance and crack pattern of lithium disilicate occlusal veneers fabricated using pressing and milling techniques with varying thicknesses. Methods Sixty lithium disilicate discs, representing occlusal veneers, were divided into four groups (n = 15) based on processing technique (IPS e.max Press or IPS e.max CAD) and thickness (0.5 or 0.8 mm). A step-stress fatigue test was applied with axial loading, consisting of 10,000 cycles/step with a step size of 50 N until failure. Fractographic analysis was performed using SEM. Statistical analysis was performed using the Kaplan–Meier test, Mantel–Cox test, and Weibull analysis. Results Both processing techniques resulted in similar fatigue resistances at 0.5 mm and 0.8 mm thicknesses. However, the 0.8 mm lithium disilicate restorations showed a significantly higher survival rate than the 0.5 mm lithium disilicate restorations (log-rank tests, χ2 = 58.6; df = 3; P

Background: Lithium disilicate occlusal veneers are popular for minimally invasive posterior teeth restoration. The aim of this study was to compare the fatigue resistance and crack pattern of lithium disilicate occlusal veneers fabricated using pressing and milling techniques with varying thicknesses. Methods: Sixty lithium disilicate discs, representing occlusal veneers, were divided into four groups (n = 15) based on processing technique (IPS e.max Press or IPS e.max CAD) and thickness (0.5 or 0.8 mm). A step-stress fatigue test was applied with axial loading, consisting of 10,000 cycles/step with a step size of 50 N until failure. Fractographic analysis was performed using SEM. Statistical analysis was performed using the Kaplan–Meier test, Mantel–Cox test, and Weibull analysis. Results: Both processing techniques resulted in similar fatigue resistances at 0.5 mm and 0.8 mm thicknesses. However, the 0.8 mm lithium disilicate restorations showed a significantly higher survival rate than the 0.5 mm lithium disilicate restorations (log-rank tests, χ2 = 58.6; df = 3; P < 0.001). Fractographic analysis revealed radial cracks originating from defects on the ceramic surface at the cementing interface, extending towards the occlusal surface. Conclusions: At 0.5 mm or 0.8 mm material thickness, the processing technique did not affect the fatigue resistance or crack patterns of the lithium disilicate occlusal veneers. However, the lithium disilicate with a thickness of 0.8 mm exhibited a superior survival probability compared to that with a thickness of 0.5 mm. [ABSTRACT FROM AUTHOR]

The light waveguiding effect of transparent glass ceramics (GCs) on mechanoluminescence (ML) signals is highly attractive for remote stress sensing and structural health monitoring applications. However, a prerequisite for generating ML in GCs is pre-irradiation with high-energy rays, which not only increases application costs but also poses a risk of GCs devitrification. Herein, we propose a safe, non-destructive, and convenient charging method for the ML of KMgF 3 : Tb3+ GCs, namely ultraviolet (UV) light charging. By effectively filling the intrinsic defects in KMgF 3 : Tb3+ nanocrystal using UV light, we achieved trap-controlled ML in rigid GCs. Moreover, this ML is attributed to thermoluminescence (TL) induced by frictional heating during mechanical stimulation. Additionally, when the GCs powder is combined with flexible polydimethylsiloxane (PDMS), a self-powered (without any pre-charging) ML induced by interfacial triboelectricity can also be achieved, which is similar to the results observed in most flexible ML systems. This work proposes a more straightforward and safer approach for applications such as mechanical sensing based on the ML of transparent GCs. [ABSTRACT FROM AUTHOR]

"Boro-mullite" is the name for mullites produced through the synthesis of boron-rich material and playing a critical role in producing high-performance materials. Also, the stability of the anatase phase in the glaze and against temperature has been addressed and improved by many studies. In situ boro-mullite crystals generated using various glass-ceramic glaze compositions that contain TiO 2 and their impact on the transformation of anatase into a rutile phase were examined in this study. Additionally, the samples' water absorption, bulk density, apparent porosity and shrinkage, Vickers hardness, and optical properties were evaluated at various Al 2 O 3 and B 2 O 3 amounts at 700 °C, 800 °C, 900 °C, 1000 °C and 1100 °C. X-ray diffraction analysis revealed that as the temperature and Al 2 O 3 ratio rose, it triggered the boro-mullite phase formation. On the other hand, increasing the Al 2 O 3 ratio led to a rise in the samples' sintering temperature and delayed the anatase to rutile phase transformation. Furthermore, the presence of corundum crystals retarded the anatase crystal size growth during the remodelling process of the conversion of anatase to rutile. While the increase in the B 2 O 3 ratio sharpened the peaks of albite crystals, the formation of rutile crystals accelerated with the increase in temperature and caused inhibition of albite formation. The albite phase's presence facilitated the creation of the liquid phase and achieved the 0.010 % water absorption and 0 % apparent porosity values as well the highest bulk density and microhardness with 2.476 g/cm3 and 550 H V. The yellowness (+b∗) values were found to be the highest at 1100 °C where the rutile crystals reached their maximum size. The anatase-rutile conversion is postponed and the increase in the yellowness value is prevented by the glaze's formation of boro-mullite. FESEM-EDS analysis showed that the temperature was the driving force in the transformation of acicular boro-mullite crystal into highly acicular prismatic needle crystal and spherical anatase crystals into the rod shape rutile. [ABSTRACT FROM AUTHOR]

The commonly used automotive head‐up display (HUD) technology is confronted with the problems of poor stability in organic resin counterpart and the unsatisfactory display effect of projection lighting source. To solve these issues, developing state‐of‐the‐art materials and designing new HUD schemes with a wide color gamut is of necessity. Herein, a series of pure red/green/blue (R/G/B) upconverting (UC) nano‐glass‐ceramics (GCs) containing lanthanide‐doped NaLuF4 nanocrystals (NCs) are synthesized in a cost‐effective, environment‐friendly, and scalable manner, simultaneously achieving high crystallinity (≈45.44%) and high transparency (>80%). Yb3+ is chosen as the sensitizer to Tm3+ (blue UC)/Ho3+ (green UC), due to its large absorption cross section from ground state 2F7/2 to excited state 2F5/2; meanwhile Er3+, Tm3+ co‐doped into NCs can obtain pure red UC emission via promoting the population of Er3+ red‐emitting 4F9/2 state. Consequently, the as‐prepared materials exhibit high R/G/B color purity of > 80% owing to the energy transfer between different lanthanide ions (Yb3+, Tm3+, Ho3+, and Er3+) upon 980 nm near‐infrared (NIR) laser excitation, and possess superior thermal reversibility/water resistivity. Remarkably, two unprecedented HUD prototypes are constructed to demonstrate the application feasibility of developed pure R/G/B UC GCs. [ABSTRACT FROM AUTHOR]

This research addresses the significant challenges of waste disposal and the need for sustainable production in the ceramics industry by introducing an approach to fabricating calcium-alumino-silicate-fluoride (CASF) based glass ceramics. Using recyclable materials such as waste soda-lime-silicate (SLS) glass and clam shells (CS) as primary precursors, a controlled melt-quenching process was employed to investigate how varying the CaO/CaF2 ratios influences the physical and structural properties of CASF glass ceramics. The waste materials and CASF glass ceramics were analyzed using X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transforms infrared (FTIR), Scanning electron microscopy (SEM), and Energy dispersive X-ray (EDX) spectroscopy. XRD indicated the crystalline structure in all CASF glass ceramics samples while FTIR spectroscopy detected several linkages, including PO43−, Si-OH, Si-O-Si, CO2, and O-H indicating the development of CASF glass ceramics. SEM analysis showed a non-uniform distribution of particles and EDX analysis, shows the calcium-to-phosphate molar ratio (Ca/P) of CASF glass ceramics. The glass ceramics labeled as G6 possessed better properties, with a minor crystalline phase identified as fluorapatite (Ca5(PO4)3F), which is compatible with the commercial bioglass. These results demonstrate a cost-effective waste-derived bioglass system used in biomedical fields. [ABSTRACT FROM AUTHOR]

The technology for the resourceful utilization of electrolytic manganese residue (EMR) in the production of superior performance glass-ceramics has garnered significant interest for its potential to maximize the consumption of waste residues in the Mn metal industry. In this study, utilizing the unique chemical composition of high-Mn EMR, superior performance glass-ceramics were prepared via a melting method, with TiO 2 utilized as a nucleating agent. The influence of the TiO 2 doping amount on the crystalline characteristics, microstructure and properties of the glass-ceramics were systematically evaluated. Additionally, the curing mechanism of Mn in glass-ceramics was scrutinized. The results show that TiO 2 enhances the precipitation of Ca(Ti,Mg,Al) (Si,Al) 2 O 6 predominant crystalline phase in the glass-ceramics. This phase transitions from a spherical to an interlocking and dense dendritic morphology. The glass-ceramics containing 10 wt% TiO 2 , which was heat-treated by nucleation at 750 °C for 2 h followed by crystallization at 900 °C for 3 h, exhibits enhanced mechanical properties and chemical stability. Its bending strength exceeds 40 MPa, with a water absorption of 0.11 %. Additionally, the acid resistance of glass-ceramics is rated at higher than 97 %, while the alkali resistance is over 99.7 %. Notably, the superior performance in Mn leaching toxicity is achieved in T10 (1.39 mg/L), which is attributable to the fact that Mn is physically coating between the crystalline and glassy phases. This technology has the potential to address the issue of heavy metal release from EMR, and provides a theoretical foundation for the industrial production path of glass-ceramics from high-Mn EMR. [ABSTRACT FROM AUTHOR]

The co-sintering behavior of a ceramic-metal bilayer is carefully investigated. This bilayer is composed of a gold film deposited by screen-printing on a silica-based low-temperature cofired ceramic (LTCC) layer. First, behaviors of both materials in free sintering are finely characterized. LTCC exhibits a viscous flow sintering mechanism, whereas the densification mechanism of gold is controlled by grain boundary diffusion (with an identified apparent activation energy of 101 ± 15 kJ mol−1). Free sintering of gold is also marked by a two-step densification process due to its large bimodal particle size distribution. A methodology is proposed to estimate gold viscosity at high temperatures directly from raw experimental data in free sintering, without performing dedicated mechanical characterizations. Based on the constitutive laws identified for LTCC and gold materials, analytical and numerical models of the bilayer co-sintering process are built. During co-sintering, stresses generated by densification kinetic mismatch between gold and LTCC are progressively relaxed by camber phenomenon. Calculated evolutions of camber in co-sintering are compared to curvature monitoring by ombroscopy. Finite element simulation in 3D fits well with the experimental data, whereas the analytical solution strongly underestimates camber rates. This shows that the simplified numerical approach suggested here leads to a robust numerical model, faithfully describing thermomechanical interactions occurring in co-sintering within the ceramic-metal bilayer. [ABSTRACT FROM AUTHOR]

Lead halide perovskite quantum dots (PeQDs) have garnered increasing attention due to their extraordinary optoelectronic properties. In recent years, femtosecond (fs) laser direct writing shows to be an effective way of inducing localized crystallization of PeQDs inside glass matrix while remaining their structural stability and optical performance. This article reviews the research progress on fs laser irradiation‐induced nucleation/growth of PeQDs in glass and discusses the latest advancements in the use of the technology for optical data storage, micrometer‐scale light‐emitting diode (LED), information security protection, and other related fields. It offers novel insights and perspectives for exploring new functionality and device application of fs laser‐printed PeQDs glass composite structures. [ABSTRACT FROM AUTHOR]

Industrial boilers operate in extreme environments and are prone to degradation caused by high temperature oxidation, corrosion, and erosion. Protective coatings provide boiler components with protection to prolong their operation lifetime. Thus, a glass-ceramic coating has been developed using a slurry spray technique on carbon steel AS/NZS 3678 substrates. Microstructure, mechanical characteristics, and high temperature performance of the coating were investigated. The coating composed of chemically inert oxide ceramics dispersed in a glassy silicate binder matrix. The adhesion strength of the coating was 10.79 ± 0.86 MPa. Coating mass loss after abrasion test was 0.013 % of the tested specimen. The coating withstood at least 75 air quenched thermal shock cycles from 800 °C to the room temperature without any visible spallation and cracks. The coating mostly remained undamaged after cyclic oxidation at 800 °C for 10 cycles. However, minor iron oxide formation was observed, specifically, in relatively thin sections of the coating. The oxidation resistance of the boiler steel has been improved with the developed coating. The linear oxidation rate constant of the boiler steel has been statistically reduced from 6.90 × 10−4 mg cm−2 s−1 to 1.95 × 10−4 mg cm−2 s−1 for coated steel (p = 0.007). The developed slurry spray glass-ceramic coating is a potential candidate for boiler environments. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to evaluate and compare the fracture resistance of MOD inlay preparations restored with two different lithium disilicate glass ceramics. Materials and Methods: Standardized MOD inlay cavities were prepared on 64 human permanent premolar teeth and divided into two groups to be restored with lithium disilicate glass-ceramic materials, i.e. Group I with IPS e.max Press HT and Group II with Shofu Vintage LD Press T. The fracture resistance was assessed using a universal testing machine and recorded in Newtons (N). Statistical analysis was done using SPSS software (Version 17.0, IBM, USA). P <0.05 was set as a statistically significant level. Unpaired Student's t -test was used to compare the fracture resistance values of both groups. Results: The mean fracture resistance value obtained for Group I (IPS e.max Press HT) was 565.04 N while that obtained for Group II was 732.75 N. Statistically significant difference was found in this intergroup comparison (P = 0.002). Conclusion: The fracture resistance of MOD inlay preparations restored with Vintage LD Press T (Shofu) was significantly higher than those restored with IPS e.max Press HT (Ivoclar Vivadent). [ABSTRACT FROM AUTHOR]

In this study, the preparation, physical characteristics, microstructural attributes, and fast neutron (FN) removal parameters of apatite-wollastonite (AW)-containing GCs doped with 10 % SiO 2 , Fe 2 O 3 , and TiO 2 were reported. Glass-ceramics containing the AW crystal structure within the SiO 2 –CaO–Al 2 O 3 –MgO–P 2 O 5 –CaF 2 glass system were prepared and doped with 10 % SiO 2 , Fe 2 O 3 , and TiO 2 by weight. The microstructural and chemical evolution of the glass-ceramics were studied using SEM/EDS. The density and Vicker hardness of the samples were experimentally evaluated, while the fast neutron removal cross-sections (Σ R) were computed using standard equations. The SEM micrograph showed densely crystallised and crack-free surface surfaces. Silicon and titanium additions did not cause a significant increase in density. However, Fe doping had a higher effect on density. The values of Σ R for pristine, SiO 2 , TiO 2 , and Fe 2 O 3 -doped AW were found to be 0.0796 cm−1, 0.0832 cm−1, 0.0869 cm−1, and 0.0904 cm−1, respectively. Compared to some other materials, such as polymers, AW-10Fe showed better attenuation for fast neutrons. The investigated ceramics could be used in tissue engineering and fast neutron moderation functions. [ABSTRACT FROM AUTHOR]

Glass and glass ceramics are very functional materials, albeit their structural complexity. Their relevance ranges from fundamental science problems in the fields of physics, chemistry, and geoscience, to applications in health areas, engineering, or technological matters that require high performance. Enhancing our understanding of these materials' performance and refining sample preparation methods remains paramount in this field. Synchrotron facilities offer a suite of powerful techniques for the detailed characterization of glasses and glass ceramics. These methods provide valuable insights into their atomic and molecular structure, phase transformations, mechanical behavior, and thermal properties, ultimately contributing to the development of improved materials for a wide range of applications. In‐depth investigations conducted under extreme conditions of pressure and temperature have yielded pivotal insights into densification mechanisms, phase transitions, crystallization kinetics, and their consequential macroscopic properties. The emergence of fourth‐generation synchrotrons brings in a wave of novel experimental possibilities that may exert a profound influence on this field in the coming decade. In this study, we unveil a selection of the remarkable capabilities now accessible to researchers at the Brazilian Synchrotron Light Source—Sirius, within the realm of extreme methods of analysis (EMA) beamline for investigating vitreous systems under extreme conditions. [ABSTRACT FROM AUTHOR]

The lack of red light components in solid-state lighting technology urgently requires the development of new efficient red-emitting bulk phosphors. Herein, we successfully prepared a kind of red-emitting glass ceramics (GCs) (λ ex = 392 nm, λ em = 613 nm) containing Eu-doped strontium fluorophosphates (Sr 5 (PO 4) 3 F:Eu) nanocrystals via a melt-quenching method in SrF 2 –K 2 CO 3 –P 2 O 5 –H 3 BO 3 glass. The heat treatment temperature was found to significantly affect the grain size of the Sr 5 (PO 4) 3 F:Eu nanocrystals as well as the transmittance of the prepared GCs. After heat treatment at 600 °C for 2 h, the Sr 5 (PO 4) 3 F:Eu nanocrystals with grain size of about 18 nm were precipitated inside the GCs (GC600), which exhibited a high transmittance of 58–70 % in the range of 500–800 nm, with a stronger luminescence intensity than that of PG. Under excitation of 392 and 464 nm wavelengths, the CIE 1931 color coordinates of GC600 were around (0.626, 0.373) and (0.638, 0.362), respectively, both falling in red region. The present Sr 5 (PO 4) 3 F:Eu GCs are promising as red phosphors for UV-pumped white-light LEDs. [ABSTRACT FROM AUTHOR]

Background. Zirconia-reinforced lithium disilicate (ZLD) is a promising material for esthetic dental restorations due to its strength, translucency, and color stability. However, its durability under accelerated aging conditions needs further investigation. The present in vitro study evaluated the effect of UV accelerated aging on the translucency and color stability of ZLD at varying thicknesses, using IPS e.max Press (LD) as a reference. Methods. Seventy-two samples were divided into two groups: high translucent (HT) Vita Ambria (ZLD) and IPS e.max Press (LD) (n=36, each). Each group was further subdivided into four thicknesses: 0.5, 1.0, 1.5, and 2.0 mm (n=9). The samples were fabricated, polished, and subjected to UV weathering for 384 hours, simulating one year of clinical service. Translucency and color changes were assessed using a spectrophotometer. Data were analyzed using SPSS 20, with independent t-test, paired t-test, and one-way ANOVA at a significance level of P≤0.05. Results. Vita Ambria exhibited significantly higher translucency before and after aging compared to IPS e.max press at all thicknesses (P=0.000). In both materials, translucency decreased when the thickness increased (P=0.000), observed before and after UV aging. Vita Ambria also displayed a greater color change (ΔE=2000) compared to IPS e.max press across all thicknesses (P=0.000). Conclusion. ZLD exhibited higher translucency than LD before and after accelerated artificial aging, indicating that the accelerated aging process adversely impacted the optical properties of the tested material. However, LD demonstrated superior color stability. [ABSTRACT FROM AUTHOR]

Ho3+-Yb3+ co-doped glass ceramics containing LiGd(WO 4) 2 were prepared by melt crystallization method. By using the methods of differential scanning calorimetry (DSC), X-ray diffraction (XRD), transmittance, and scanning electron microscopy (SEM), the optimal heat treatment condition for the samples was identified to be 580 °C/140 min. In these conditions, the transmittance of glass ceramic is about 75 % in the 380–780 nm range. In the upconversion emission spectra, strong green emission (543 nm) and red emission (650 nm) due to 5F 4 /5S 2 , 5F 5 →5I 8 transitions are observed at 980 nm excitation. Additionally, the optimum doping concentrations of Ho3+ and Yb3+ were 0.12 % and 0.4 %. The crystal field changes around dopant ions were analyzed using J-O theory and Eu3+ probe to explain the up-conversion luminescence enhancement of glass ceramics containing LiGd(WO 4) 2. The chrominance coordinates of 0.12 % Ho3+-0.4 % Yb3+ co-doped glass ceramics are located in the green light region, and the color purity is 95.6 %. In summary, Ho3+-Yb3+ co-doped transparent glass ceramics containing LiGd(WO 4) 2 have potential applications in infrared detection and green solid-state lasers. [ABSTRACT FROM AUTHOR]

Silica-based glass ceramics have been extensively used in biomedical applications due to their superior biocompatibility and controllable properties. However, their low mechanical strength limits their application. This could be addressed by optimizing the crystalline phase which determines their final properties. Silicon nitride has attracted attention due to its combination of good mechanical and biological properties. Therefore, to combine the advantage of silica-based glass and silicon nitride ceramic, this study developed a silicon nitride-silicon dioxide (Si 3 N 4 –SiO 2) glass ceramics. The effects of spark plasma sintering parameters on the structural and mechanical properties of Si 3 N 4 –SiO 2 glass ceramics were investigated. Full densification was reached at a sintering temperature of 1300 °C, a holding time of 10 min and an applied pressure of 80 MPa (relative density = 99.19 %). No silicon oxynitride (Si 2 N 2 O) crystalline phase was formed in the sintered glass ceramics, as confirmed by XRD. The interface between the β-Si 3 N 4 crystalline and amorphous SiO 2 was investigated by HRTEM, and the results indicated that an amorphous interfacial oxide was formed at the interface. The mechanical properties increased with increasing sintering temperature, as a result of the increased density. The Si 3 N 4 –SiO 2 glass ceramics sintered at 1500 °C exhibited the highest value of toughness and flexural strength, at 4.6 ± 0.28 MPa m1/2 and 360 ± 27 MPa. The indentation cracks observed by SEM showed that the large β-Si 3 N 4 grains promoted crack deflection, while the equiaxed Si 3 N 4 grains with a lower aspect ratio led to transgranular fracture. The mechanical properties of these Si 3 N 4 –SiO 2 glass ceramics are comparable to commercial glass ceramics, indicating their promising aspects in biomedical applications. [ABSTRACT FROM AUTHOR]

This paper presents a process for obtaining glass ceramics based on corundum modified by borosilicate glass with various additives. The described Al2O3 /SiO2–B2O3–CaO–MgO–Na2O–K2O system has been developed for use in LTCC technology and exhibits a sintering temperature of less than 950°C. The impact of varying the sintering additive content on the firing temperature, microstructure, ceramic, and electrophysical properties of the resulting ceramics was investigated. The developed material exhibited a dielectric constant of εr= 6.73 – 6.82 and tangent of the dielectric loss angle of tan δ = 8.0 – 8.6 × 10 –3 at a frequency of f = 1 MHz. [ABSTRACT FROM AUTHOR]

Transparent glass-ceramics containing nanorods are attractive for many applications. In this work, transparent aluminoborosilicate glass-ceramics containing aluminum borate nanorods are reported. Effects of Al 2 O 3 and SiO 2 concentrations on the thermal properties and crystallization of aluminoborosilicate glasses are studied. It is found that lithium aluminosilicate nanocrystals and Al 4 B 2 O 9 nanorods are co-precipitated in glasses with Al 2 O 3 /SiO 2 molar ratios of 0.29 and 0.33, and only Al 4 B 2 O 9 nanorods are precipitated in glasses with Al 2 O 3 /SiO 2 molar ratios of 0.375 and 0.42. Precipitation of these nanocrystalline phases leads to the enhancement in Vickers hardness. Glass-ceramics with Al 2 O 3 /SiO 2 molar ratios of 0.375 and 0.42 are highly transparent in the visible region due to the small size of the Al 4 B 2 O 9 nanorods precipitated inside. [ABSTRACT FROM AUTHOR]

Conductivity spectra of heat-treated 50B2O3·30Li2O·20ZnO glass samples for different hold times, 2 h, 4 h, 6 h, and 8 h, were investigated across a wide temperature range (413–573 K) and frequency range (0.1–106 Hz). Parameters like crossover frequency (ωH), frequency exponent (s), and direct current conductivity (σdc) have been retrieved from the Almond West model fit of the experimental data of ac conductivity. The applicability of overlapping large polaron tunneling has been observed in the examined glass ceramics system. The activation energy determined from the conductivity, electric modulus, and impedance analysis shows a consistent trend. The glass composition 50B2O3·30Li2O·20ZnO exhibits the highest value of conductivity ~ 8.3 × 10−6 Scm−1 when crystallized for 4 h at 573 K, making it an ideal choice for electrode material in energy storage devices. An enhancement in electrical conductivity was observed by converting the 50B2O3·30Li2O·20ZnO glass samples into glass ceramics. Formation of the layered structure was observed from SEM micrographs, which indicates that the studied glass ceramics are appropriate for electric double-layer capacitance fabrication (EDLC). [ABSTRACT FROM AUTHOR]

In this paper, the crystallization behavior of 50ZnO:47B2O3:3Nb2O3:0.5Eu2O3 (G-0 h) glass has been investigated in detail by DSC, XRD and TEM analysis. The luminescent properties of the resulting glass-ceramics were also investigated. By XRD and TEM analysis, crystallization of several crystalline phases has been proved (α-Zn3B2O6, β-Zn3B2O6 and ZnNb2O6). By calculating crystal parameters, it was found that europium ions are successfully incorporated in the β-Zn3B2O6. Photo-luminescent spectra showed increased emission in the resulting glass-ceramic samples compared to the parent glass sample due to higher asymmetry of Eu3+ ions in the obtained crystalline phases. It was established that the optimum emission intensity is registered for glass-ceramic samples obtained after 25 h heat treatment of the parent glass. [ABSTRACT FROM AUTHOR]

In the study, the influence of doping apatite-wollastonite (AW) glass-ceramics (GCs) with B 2 O 3 on the structural, physical, microstructural, and light and heavy particle interaction properties is presented. Using the solid-state reaction and the cold isostatic press method, pristine AW, 10 wt% (AW-B10), and 20 wt% (AW-B20) B 2 O 3 -doped AW GCs were prepared. The prepared GCs were subject to structural, chemical compositional, and surface morphological investigation through standard experimental processes. Furthermore, the neutron (fast and thermal) and charged radiation (electron, proton, alpha, and carbon ion) interactional parameters of the GCs were obtained through standard theoretical models and software. The density of AW (2.91 gcm−3) increases to about 2.957 and 2.986 gcm−3 as B 2 O 3 increases to 10 and 20 wt%, respectively. The presence of boron oxide supported the wollastonite phase to remain glass and suppressed crystallisation in the AW GCs. Doping AW with B 2 O 3 improved the interaction probabilities of the GCs with fast and thermal neutrons, electrons, protons, alpha particles, and carbon ions. B-rich AW is thus potentially useful as a target material in human tissues for boron neutron capture therapy for the management of cancer and tumours, isolating or shielding specific tissues in ion beam therapy processes, and other techniques that require the exposure of human tissues to irradiation. [ABSTRACT FROM AUTHOR]