The effect of zeolite incorporation on the physical properties of silver-reinforced glass ionomer cement

Abstract

Zeolite can impart antibacterial properties to dental materials in the long-term when incorporated with inorganic cations. However, due to its porosity, it may jeopardize the mechanical integrity of the dental material. The aim of this project was to determine the effect on physical properties when zeolite is added to commercially available Ag-reinforced Glass Ionomer Cement (GIC). Sample groups were prepared according to the percentage of zeolite-clinoptilolite (0% - control, 0.5%, 1%, 2%, and 4% wt) added to Ag-GIC. Water sorption, solubility, Vickers hardness, and flexural strength were determined. Specifically, 10 × 2 mm circular disks were fabricated for the Vickers hardness, water sorption, and water solubility tests and 25 × 5 × 2 mm bars were created for the flexural strength test. The results from the surface hardness, water sorption, and flexural strength tests suggested that adding 0.5–4% wt of zeolite to Ag-reinforced GIC did not diminish its physical properties. However, the water solubility results showed that higher concentrations (2–4% wt) of zeolite had a statistically significant increase in water solubility compared to the control. Up to 4% wt zeolite can be incorporated into Ag-reinforced GIC without compromising mechanical properties. Incorporation of 0.5–1% wt zeolite to Ag-reinforced GIC will maintain an adequate surface hardness, water sorption, and flexural strength without compromising water solubility. Further research is needed to determine the effects of higher water solubility on clinical efficacy of zeolite modified Ag-GIC.

Effect of Zeolite Incorporation on the Ion Release Properties of Silver-Reinforced Glass Ionomer Cement

“…The amount of silver ion release from silver-reinforced GIC was significantly higher for all concentrations of added silver–zeolite compared to the control. All tested concentrations (0.5–4% wt) were shown to maintain the physical properties of GIC in a previous study conducted in our laboratory [ 38 ]. In this study, higher concentrations of incorporated zeolite resulted in increased silver ion release.…”

“…A previous study by our lab group tested the effect of adding zeolite to silver-reinforced GIC due to determine whether the porous nature of zeolite would compromise the physical properties of the material [ 38 ]. The addition of zeolite up to 4% by weight was found to have little detrimental effect on the physical properties of silver-reinforced GIC, allowing the material to retain its original surface hardness and flexural strength [ 38 ]. In addition, low concentrations of zeolite appear to have a negligible effect on the optical properties and light gray color of silver-reinforced GIC.…”

Evaluation of Antibacterial Activity of a Bioactive Restorative Material Versus a Glass-Ionomer Cement on Streptococcus Mutans: In-Vitro Study

“…Ketac™ Silver was chosen over a conventional GIC as the most appropriate material for the purpose of this study thanks to its improved antibacterial activity against cariogenic biofilm, provided by the addition of silver [ 33 , 37 , 38 ]…”

“…Ketac™ Silver was chosen over a conventional GIC as the most appropriate material for the purpose of this study thanks to its improved antibacterial activity against cariogenic biofilm, provided by the addition of silver [33,37,38] Silver ions exert effective antimicrobial activity through three major mechanisms: inhibition of cellular respiration and disruption of metabolic pathways by generating reactive oxygen species, disruption of DNA replication, and direct damage of the bacterial cell wall through reactions with peptidoglycan [39]. Additionally, the addition of silver particles to GICs does not negatively affect their mechanical and physical properties [40,41] As a side note, according to the manufacturer's instructions, the setting time for Ketac™ Silver is generally 5 min from the beginning of mixing at room temperature within 23 • C, while it is accelerated at higher room temperatures.…”