Cell Biocompatibility, Antimicrobial, Antibiofilm, and Mechanical Properties of Dental Glass Ionomer Cement Containing Silver-loaded Silica Nanoparticles

Reducing the risk of bacterial colonization of dental materials can potentially decrease the need for systemic antibiotic therapies, thus minimizing the risks of antibiotic resistance and adverse drug reactions. Furthermore, the antimicrobial and anti-biofilm properties of these materials contribute to enhanced patient safety by lowering the likelihood of post-operative infections. The aim of this in vitro study was to investigate the effect of adding mesoporous silica nanoparticles containing silver on the safety, antimicrobial, and mechanical properties of glass ionomer cement.

Glass ionomer cement was mixed with mesoporous silica nanoparticles containing silver until completely blended. The MTT method was used to assess the safety of the material. The microbroth dilution method was used to investigate the antibacterial effect of the nanoparticles and determine the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). The disk diffusion method was also used to evaluate the microbial activity of the nanoparticle-containing cements. For the solubility test, materials were prepared according to ISO 4049, and the dissolution test was performed. The Shapiro-Wilk test was used to assess the normality of the data. The t-test was used to compare the results between groups. GraphPad software was used to analyze the data. A probability value of less than 0.05 was considered significant.

Significant differences were observed in the growth inhibition zones among the groups (P=0.001), with the cement containing 5% Nanoparticles Showing Superior Results Compared To Those With 3% (P=0.03) And 1% (P=0.01). Similarly, the Minimum Inhibitory Concentration (MIC) analysis revealed a notable difference between groups (P=0.0001), where the 5% nanoparticle cement outperformed the 3% (P=0.001) and 1% (P=0.02) formulations. For Minimum Bactericidal Concentration (MBC), the 5% nanoparticle group again demonstrated significantly better results (P=0.0001) compared to the 3% (P=0.001) and 1% (P=0.0001) groups. The Minimum Biofilm Inhibitory Concentration (MBIC) followed a similar trend (P=0.0001), with the 5% nanoparticle cement yielding better outcomes than the 3% (P=0.001) and 1% (P=0.0001) formulations. Solubility tests indicated no significant difference between cements with and without nanoparticles (P=0.4). However, water absorption measurements showed a significant increase in the nanoparticle-containing cement compared to the control (P=0.02). Lastly, flexural strength assessments found no statistically significant difference between nanoparticle-containing and nanoparticle-free cements (P=0.7).

The findings of this study demonstrate that incorporating 5% nanoparticles into cement formulations significantly enhances their antimicrobial properties, as evidenced by improved growth inhibition zones, MIC, MBC, and MBIC values compared to lower nanoparticle concentrations (3% and 1%). While the inclusion of nanoparticles increases water absorption, it does not negatively affect the solubility or flexural strength of the cement. These results suggest that nanoparticle-enriched cement, particularly at a 5% concentration, holds potential for applications requiring enhanced antimicrobial activity without compromising structural integrity.