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This article discusses the biomaterial properties of computer-aided design/computer-assisted manufacture(CAD/CAM) high-strength glass-ceramics. It includes the advantages of high-strength glass-ceramic restoration, the manufacture of glass-ceramics, classification of CAD/CAM high-strength glass-ceramics, and its mechanical properties.

The present work was oriented to develop a high-performance film for LTCC application through using a kind of silane coupling agent (SCA) to modify the CBS (CaO-B 2 O 3 -SiO 2 ) glass-ceramic powders in tape casting process. The coupling mechanism of the silane coupling agent interacting with the powders was illustrated in detail, and the optimum amount of additions was determined by the infrared transmittance and contact angle experiment. The rheological properties of suspensions, the compactness and tensile breaking strength of the green tape were texted by using a number of quantitative and qualitative instruments. Furthermore, when the green tapes sintered at 820 °C, the sintering characteristics and microwave properties of sintered body with different SCA additions was also analyzed. Based on the experimental results, it revealed that the powders modified by SCA with 1.5 wt% additions could induce the most excellent performance of film, with the density at 1.57 g/cm 3 and the tensile strength at 2.57 MPa, possessing the highest density and best microwave properties of sintered body: the density of sintered body was 2.48 g/cm 3 , the dielectric constant and dielectric loss was ε r = 5.93, tan δ =8 × 10 −4 at 12 Hz. [ABSTRACT FROM AUTHOR]

Implant therapy and CAD/CAM technologies are advancing quickly, providing predictable esthetic and functional treatment options. A recent development involves the use of zirconia-reinforced lithium-silicate ceramic for fabrication of implant-supported restorations. Suitable for monolithic crowns, the material provides the optical advantages of a silicate ceramic with improved physical strength. Several prerequisites, however, are necessary to fabricate screw-retained monolithic restorations in the anterior maxilla. This case report demonstrates the clinical steps to fabricate a monolithic ceramic CAD/CAM crown on an immediately placed dental implant in the esthetic zone. [ABSTRACT FROM AUTHOR]

In this study fabrication of rod-like bioactive glass-ceramics (BGCs) using hydrothermal treatment based on a sol-gel precursor is reported for the first time. BGCs with composition 58 wt% SiO 2 , 33 wt% CaO and 9 wt% P 2 O 5 were synthesized in different thermal conditions (200 and 220 °C) and characterised with regard to morphology, chemical composition and crystallinity. The bioactivity of the materials was assessed by immersion in simulated body fluid for up to 7 days. The results revealed that as the reaction temperature increased from 200 to 220 °C, the diameter of rods was reduced from microscale to nanoscale and the crystallinity was enhanced. It was also found that the BGC nanorods have higher surface area and consequently enhanced bioactivity than BGC microrods. This technique provides a facile method for rapid production of BGC nanorods at relatively low temperature which may have the potential to be used as bioactive composite reinforcement or for bone grafting applications. [ABSTRACT FROM AUTHOR]

Au-Cu tailings (ACTs) are gold mining industry by-products that require further treatment before disposal to alleviate polluting the environment such as landfill, plant cover or using material production. This study focuses on the preparation and properties of a material called glass-ceramics that was prepared by a melting method with ACT, as raw materials, and without additional nucleating agents. The nucleation and crystallization temperature of the base glasses were determined by differential scanning calorimetry (DSC). The microstructure and properties of the glass-ceramics were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), a bending strength test, a microhardness test, linear thermal expansion coefficient, and a wear-and-tear test, thereby obtaining the best optimum formula composition and the process parameters. The results show that the utilization of ACT can be up to 77.56 wt.%, which can make good use of ACT and develop decorated glass-ceramics with perfect properties. Two crystalline phases are diopside ((Mg0.6Fe0.2Al0.2) Ca(Si1.5Al0.5)O6) and hedenbergite (Ca(Fe0.821Al0.179) (SiAl0.822Fe0.178O6)) which are formed in the glass-ceramic samples. The obtained glass-ceramics show the properties of maximum bending strength of 209.6 MPa, density of 3.23 g/cm³, hardness of 1008.7 kgf/mm² and wear resistance of 0.039 mg/g. [ABSTRACT FROM AUTHOR]

Glasses with cation composition of M:Si:Al = 3.45:3:2 (where M = Er and Y) with varying nitrogen contents (0, 5, 8, 15 and 22 eq.%) have been prepared by ball milling in alcohol media. These Er- and Y-sialon glasses were heat-treated at temperatures in the range of 950-1200 °C for 10 h to study the crystal phase(s) obtained. Samples were characterised by SEM and XRD and obtained data from XRD were further analysed to obtain unit cell parameters of some phases. It is shown that it is possible to obtain B-phase (Y2SiAlO5N) from these glass compositions with relatively low nitrogen contents (5 and 8 eq.%N) but with different unit cell parameters (i.e. a = 3.77-3.81 Å and c = 9.83-9.97 Å) to those reported previously in the literature, suggesting that there are some compositional differences between B-phases obtained from different nitrogen content glasses as well as different modifier cations. Long-term heat treatment studies revealed that the stability range of temperature for Er-B-phase is more extensive than its Y-B-phase equivalent. [ABSTRACT FROM AUTHOR]

Gelcasting is a colloidal processing method for fabricating high-strength and complex shape ceramic green bodies. However, industry has been reluctant to use the gelcasting technique because the most commonly used gel, acrylamide ( AM), is a neurotoxin. Here, we report an attempt at the gelcasting of fused silica glass using a natural and nontoxic gel, glutinous rice flour ( GRF) as binder. The GRF-based aqueous system was found to behave excellently in the gelcasting process. Flexural strength of fused silica green bodies solidified with only 3 wt% GRF is up to 11.87 MPa. Bulk density and flexural strength of fused silica glass sintered at 1275 °C are 1.75 g/cm3 and 47.02 MPa, respectively. [ABSTRACT FROM AUTHOR]

The result of development work on the composition of batch and matching the firing temperature for the production of glass ceramic material for purposes of obtaining matched junctions with molybdenum owing to close values of the CLTE are presented. Validation is given for using cullet comprised of window sheet glass as a binder in amount 30% and firing at temperature 1000°C. [ABSTRACT FROM AUTHOR]

Mixed color waste glass extracted from municipal solid waste is either not recycled, in which case it is an environmental and financial liability, or it is used in relatively low value applications such as normal weight aggregate. Here, we report on converting it into a novel glass-ceramic lightweight aggregate (LWA), potentially suitable for high added value applications in structural concrete (upcycling). The artificial LWA particles were formed by rapidly sintering (<10 min) waste glass powder with clay mixes using sodium silicate as binder and borate salt as flux. Composition and processing were optimized using response surface methodology (RSM) modeling, and specifically (i) a combined process-mixture dual RSM, and (ii) multiobjective optimization functions. The optimization considered raw materials and energy costs. Mineralogical and physical transformations occur during sintering and a cellular vesicular glass-ceramic composite microstructure is formed, with strong correlations existing between bloating/shrinkage during sintering, density and water adsorption/absorption. The diametrical expansion could be effectively modeled via the RSM and controlled to meet a wide range of specifications; here we optimized for LWA structural concrete. The optimally designed LWA is sintered in comparatively low temperatures (825-835 °C), thus potentially saving costs and lowering emissions; it had exceptionally low water adsorption/ absorption (6.1-7.2% w/wd; optimization target: 1.5-7.5% w/wd); while remaining substantially lightweight (density: 1.24-1.28 g.cm-3; target: 0.9-1.3 g.cm-3). This is a considerable advancement for designing effective environmentally friendly lightweight concrete constructions, and boosting resource efficiency of waste glass flows. [ABSTRACT FROM AUTHOR]