Efeito antibacteriano do cimento de ionômero de vidro modificado por nanopartículas de quitosana

Abstract

Introduction: Glass ionomer cements (CIVs) have several clinical indications due mainly to the properties of chemical bonding to dental structure, cariostatic activity and reduction of acidogenicity of the Streptococcus mutans biofilm. However, the incorporation of new compounds into the cement can improve its antibacterial properties. Objective: To investigate the antibacterial effect against S. mutans of an anhydrous glass ionomer cement modified by the incorporation of a suspension of chitosan nanoparticles, added to the liquid of the material in different percentages. Methodology: Chitosan nanoparticles (ChNPs) were synthesized by ionic gelation (3.85 mg / mL) and incorporated into the VIC liquid at the time of spatulation in different percentages by volume (v / v%), forming 5 groups: G1 with 0% suspension of chitosan nanoparticles (ChNps) (control), G2 with 20% suspension of ChNPs, G3 with 50% suspension of ChNPs, G4 with 80% suspension of ChNPs and G5 with 100% suspension of ChNPs. Petri dishes containing Mitis Salivarius agar were seeded with inoculum of S. mutans (UA 159) and 6 wells (6 mm diameter) were prepared in each plate for insertion of the cements, according to each group, with the aid of the Centrix syringe. The plates were held for 1 h at room temperature for diffusion of the substances and incubated for 48 h at 37oC under microaerophilia using the candle flame method. Afterwards, the inhibition halos around the cements were measured using a digital caliper. Data were analyzed by ANOVA and Tukey ( = 0.05). Results: The group G5 had the highest inhibition halo values against S. mutans, with a statistically significant difference between the other groups (p = 0.04). There was no significant difference for the values of inhibition halos between the other groups. Conclusion: The 100% substitution of glass ionomer cement liquid by a nanoparticle suspension of chitosan, group G5, increased the antibacterial activity of the material against S. mutans.