Microhardness and Fluoride Release of Glass Ionomer Cement Modified with a Novel Al Complex to Enhance Its Antimicrobial Activity.

OBJECTIVES

To synthesize and characterize a novel Al complex with 2-(2-hydroxyphenyl)-1H-benzimidazole (HL) to be added to a restorative glass ionomer cement (GIC) to enhance its antimicrobial activities and to evaluate the Vickers microhardness (HV) and fluoride release (FR) of the modified GIC.

MATERIALS AND METHODS

Al complex was synthesized by the addition of 1 mmol (0.210 g) of HL to 1 mmol (0.342 g) of aluminum sulfate in ethanol. The resulting solution was then refluxed under stirring for 24 h and then collected by filtration and dried in a vacuum desiccator over an anhydrous CaCl. Characterization of Al complex was carried out by Fourier transform infrared spectroscopy (FTIR), elemental microanalysis, thermal gravimetric analysis (TGA), molar conductance, H NMR spectra, and electron impact-mass spectrometry. The antimicrobial activity of Al complex-modified GIC (Al-GIC) was studied by the "cut plug method" against Gram-negative bacteria () and Gram-positive bacteria (, , and ) and fungi (). HV was evaluated by a digital microhardness tester (Zwick/Roell, Indentec, ZHV-S, West Midlands, England). Fluoride levels in ppm were obtained using the ion-selective electrode connected to a digital meter. A one-way ANOVA and Bonferroni test were used to analyze the data with the significance level established at ≤ 0.05.

RESULTS

Synthesis of Al complex was confirmed by FTIR, elemental microanalysis TGA, molar conductance, H NMR spectra, and electron impact-mass spectrometry. Al-GICs exhibited an enhanced antibacterial activity against all studied microorganisms as confirmed by the growth of inhibition zones compared to control GIC (C-GIC). Though there was a slight reduction in HV and FR with increasing the added percent of Al complex, no significant differences were found between the studied groups.

CONCLUSIONS

Addition of Al complex to GIC powder enhanced the antimicrobial activity of GIC materials. As there was a negligible insignificant reduction in HV and FR upon the addition of Al complex, Al-GICs can be used with a guaranteed degree of clinical success.