Phase Formation, Mechanical Strength, and Bioactive Properties of Lithium Disilicate Glass–Ceramics with Different Al₂O₃ Contents

Owing to its excellent mechanical properties and aesthetic tooth-like appearance, lithium disilicate glass–ceramic is more attractive as a crown for dental restorations. In this study, lithium disilicate glass–ceramics were prepared from SiO2–Li2O–K2O–P2O5–CeO2 glass systems with various Al2O3 contents. The mixed glass was then heat-treated at 600 °C and 800 °C for 2 h to form glass–ceramic samples. Phase formation, microstructure, mechanical properties and bioactivity were investigated. The phase formation analysis confirmed the presence of Li2Si2O5 in all the samples. The glass–ceramic sample with an Al2O3 content of 1 wt% showed rod-like Li2Si2O5 crystals that could contribute to the delay in crack propagation and demonstrated the highest mechanical properties. Surface treatment with hydrofluoric acid followed by a silane-coupling agent provided the highest micro-shear bond strength for all ceramic conditions, with no significant difference between ceramic samples. The biocompatibility tests of the material showed that Al2O3-added lithium disilicate glass–ceramic sample was bioactive, thus activating protein production and stimulating the alkaline phosphatase (ALP) activity of osteoblast-like cells

Engineering antibacterial tannic acid/polyethyleneimine coatings on lithium disilicate glass-ceramics for dental applications

This study introduces an innovative approach to enhance the antibacterial properties of lithium disilicate glass ceramics, widely used in dental restorations. We explored the efficacy of tannic acid (TA) and polyethyleneimine (PEI) as coating agents, capitalizing on a robust defense against microbial colonization and biofilm formation. We employed various analytical techniques, including differential thermal analysis (DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), to characterize the physical, chemical, and antibacterial properties of the TA/PEI coated glass-ceramics. Results indicated a notable improvement in the mechanical properties, such as Weibull modulus, elastic modulus, and fracture toughness of the coated samples. Moreover, the TA/PEI coatings displayed superior thermal stability and effective leaching behavior in different pH, pertinent to dental applications. Significantly, the TA/PEI coatings exhibited high antibacterial activity against Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria, making them promising candidates for enhancing the bioactivity of dental restorative materials. This study lays the foundation for developing advanced antibacterial coatings for dental applications, aiming to improve patient outcomes in dental care