Antibacterial Effect of Silver Nanoparticles Versus Chlorhexidine Against Streptococcus mutans and Lactobacillus casei

Abstract

The porpoise of the study was to evaluate the antibacterial effect of silver nanoparticles (Ag-NPs) versus chlorhexidine (CHX) against Streptococcus mutans and Lactobacillus casei. Three different reducing agents were used for the synthesis and characterization of Ag-NPs: sodium borohydride (NaBH 4), a chemical method, and Heterotheca inuloides (Hi) and Camellia sinensis (Cs), two eco-friendly methods. The synthesized substance was deposited on deciduous teeth. Its behavior in dental tissues was evaluated through an energy dispersive X-ray spectroscopy (EDS) analysis, using a scanning electron microscope (SEM). The characterization of Ag-NPs in terms of shape, size, and polydispersity was performed through spectrophotometry of ultraviolet-visible light analysis (UV-vis), as well as by transmission electron microscopy. Isolation and culture of strains S. mutans and L. casei were done to perform the microbiological analysis. In Petri dishes, paper discs containing different concentrations of Ag-NPs (synthesized by Hi, and by Cs) were deposited and tested along with paper discs containing CHX. Their antibacterial effect against both bacteria was evaluated by the inhibition zones test. By means of UV-Vis and TEM analysis, it was possible to observe that Heterotheca inuloides produced smaller and more stable nanoparticles, also in greater quantities (17.5 nm), when compared to Camellia sinensis. EDS analysis through SEM showed a 6.25 average absorption of silver in dental tissues. The microbiological analysis revealed a greater zone of inhibition when the test bacteria were in contact with 20 μl of Ag-NPs, synthesized by Hi, being statistically significant (p < 0.05), compared to the growth inhibition zones produced by Cs, and CHX against both strains. We can conclude that eco-friendly methods produced Ag-NPs with an important antibacterial effect in both strains.

Cytotoxicity of novel plant-based silver nanoparticles on fibroblasts for use in dental and medical applications

“…It is evident from recent reports that Chlorhexidine is being used less post-surgically due to interruption of fibroblast, and osteoblast activity which may delay wound healing activity at surgical sites [15]. Recent studies on silver nanoparticles have shown that they are comparable to Chlorhexidine's antimicrobial action even at lower concentrations than their quaternary ammonium counterparts [16]. Certain studies have even shown that silver nanoparticles can reduce inflammation around surgical sites leading to reduced healing time [17].…”

Plant Extract-Synthesized Silver Nanoparticles for Application in Dental Therapy

“…One study showed that the biogenic AgNPs have improved activities compared to the chemically synthesized AgNPs and CHX. The chemical AgNPs were reduced by sodium borohydride (NaBH 4 ), and two green AgNPs were produced using extracts of Heterotheca inuloides (Hi) and Camellia sinensis (Cs) [124]. Hi produced smaller and more stable NPs when compared to Cs-AgNPs.…”

“…The green AgNPs inhibited the growth of S. mutans and L. casei better than 2% CHX, while the smaller Hi-AgNPs had enhanced antibacterial activity compared to the Cs-AgNPs. [124].…”

Usos de las nanopartículas de plata (AgNPs) en odontología

“…22201/ceiich.24485691e.2024.33.69816 Verónica Gasga Tapia, Aída Hamdan-Partida, Teresa Leonor Sánchez Pérez, Francisco Javier Martínez Ruiz, Jaime Bustos-Martínez Recientes investigaciones indican que soluciones antimicrobianas de AgNPs evitan la formación de biopelícula y actúan contra las principales bacterias cariogénicas. Se han evaluado formulaciones de AgNPs contra S. mutans con efectos antibacterianos (Misba et al, 2016;Schwass et al, 2018;Morales et al, 2018;Elgamily et al, 2018). Pérez-Díaz et al (2015) probaron la actividad antimicrobiana de las AgNPs contra un aislado clínico de S. mutans, encontrando una actividad antibiopelícula, contra S. mutans y presentaron compatibilidad con fibroblastos humanos.…”