# Green-Synthesized TiO2 Nanoparticles Improve Mechanical Performance of Glass Ionomer Cements

## TL;DR

This study shows that adding green-synthesized TiO2 nanoparticles from hemp improves the strength of dental cements.

## Contribution

The novel use of hemp-derived TiO2 nanoparticles to enhance the mechanical properties of glass ionomer cements is introduced.

## Key findings

- Low concentrations of TiO2 nanoparticles significantly improved the flexural strength and microhardness of restorative GICs.
- Higher nanoparticle concentrations caused agglomeration and reduced performance in some GIC formulations.
- Green-synthesized TiO2 nanoparticles offer a sustainable method for reinforcing dental biomaterials.

## Abstract

Glass ionomer cements (GICs) are widely used in restorative and luting dentistry due to their fluoride release and chemical adhesion to dental tissues; however, their limited mechanical strength necessitates reinforcement strategies. The objective of this study was to investigate the effects of hemp-derived, green-synthesized titanium dioxide (TiO2) nanoparticles on the surface and mechanical properties of two commercially available GICs with different clinical indications. TiO2 nanoparticles were synthesized using Cannabis sativa leaf extract via a biogenic reduction method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX), confirming anatase-phase crystallinity, spherical morphology, and nanoscale particle size (28–49 nm). The nanoparticles were incorporated into Ketac™ Molar Easymix (restorative) and Ketac™ Cem Radiopaque (luting) GICs at 1%, 3%, and 5% (w/w), with nanoparticle-free formulations serving as controls (n = 10). Surface roughness, Vickers microhardness, and flexural strength were evaluated. Surface roughness increased in a concentration-dependent manner in both materials, with the highest values observed at 5% TiO2 incorporation. In Ketac™ Molar Easymix, 1% and 3% TiO2 significantly enhanced flexural strength and microhardness, whereas 5% resulted in reduced performance, consistent with SEM-observed nanoparticle agglomeration. In contrast, Ketac™ Cem Radiopaque exhibited no significant changes in flexural strength, although maximum microhardness values were recorded at 1% TiO2 concentration. These findings demonstrate that low concentrations of hemp-derived TiO2 nanoparticles can effectively reinforce restorative GICs and highlight the potential of green nanotechnology as a sustainable approach for improving dental biomaterials.