# Evaluation of the antibacterial activity, surface microhardness, and color change of glass ionomer cement containing green synthesized Ag@MoS2 nanocomposite after thermal aging

## TL;DR

This study tests how adding green-synthesized silver and Ag@MoS2 nanoparticles to dental cement affects its antibacterial properties, hardness, and color after heat exposure.

## Contribution

The study introduces green-synthesized Ag@MoS2 nanocomposites as an effective antibacterial additive for glass ionomer cement without compromising material properties.

## Key findings

- Ag@MoS2 nanocomposites showed the highest antibacterial efficacy against S. mutans.
- Nanoparticle addition did not significantly affect microhardness or color of the cement.
- Thermal aging did not reduce the antibacterial or physical properties of the modified cements.

## Abstract

The aim of our study is to compare the antibacterial activity, surface microhardness, and color change of glass ionomer cement (GIC) with the addition of green-synthesized silver nanoparticles (Ag NP) and silver molybdenum disulfide (Ag@MoS2) nanocomposites (NC) after thermal aging conditions.

Our study consisted of five groups (n = 7): only GIC (control); GIC + Green-synthesized Ag NP; GIC + Green-synthesized Ag@MoS2 NC; GIC + Chemically synthesized Ag NP, and GIC + Chemically synthesized Ag@MoS2 NC. The nanoparticles were synthesized, characterized using the required protocols, and added to the liquid part of the GIC. Disk-shaped samples with a diameter of 10 mm and a thickness of 2 mm were prepared with the nanoparticle-mixed GIC and used to determine the S. mutans live/dead assay analysis, MTT metabolic activity test, agar disk diffusion test, lactic acid production, and CFUs values. The microhardness and color change of the samples were evaluated, and statistical analysis was performed (α = 0.05).

Statistically significant differences were observed between the experimental and the control groups regarding live bacteria ratio, lactic acid production, inhibition zone, CFUs, and S. mutans metabolic activity (p < 0.05). The highest antibacterial efficacy in the experimental groups was observed in the Ag@MoS2 NC groups. The addition of Ag NP and Ag@MoS2 NC synthesized by green and chemical methods did not adversely affect the microhardness or cause clinically significant changes in the color of the experimental GICs (p > 0.05). Thermal aging did not adversely affect the obtained results.

Adding Ag NP and Ag@MoS2 NC to GICs may provide sufficient antibacterial efficacy without adversely affecting color or microhardness values even after thermal aging.