Addition of silver nanoparticle solutions to alginate: microbiological and mechanical analysis

This study assesses the antimicrobial activity and physical alterations of alginate impression material in the presence of silver nanoparticle (AgNP) solutions. The samples were assigned to five groups according to the type of alginate and solution: (JW) Jeltrate + distilled water; (JCHX) Jeltrate + 0.2% chlorhexidine digluconate; (JAgNP_0.2%) Jeltrate + 0.2% AgNP; (JAgNP_1%) Jeltrate + 1% AgNP; and (AW) Avagel + distilled water. AgNPs were synthesized from the fungus Trichoderma reesei. Fifty impressions were made (n=10) from a matrix, from which plaster models were fabricated. Surface detail reproduction and dimensional stability were analyzed under a light microscope. Surface detail reproduction was achieved by replicating a 50µm line on the plaster model. Dimensional stability was calculated from measurements of X' and X'' in the matrix and plaster models. The antimicrobial effect was assessed independently by measuring the formation of zones of inhibition around the alginate molds (n=3) in agar medium containing Streptococcus mutans and Candida albicans. Dimensional stability values were subjected to the ANOVA and Tukey's post-hoc test (α=0.05). JCHX showed the highest dimensional stability and differed significantly from the other groups (p<0.05). A 50µm line was reproduced in the plaster for all tested groups, regardless of the impression material and antimicrobial solution. AgNPs incorporated into the alginate mixture did not produce dimensional changes in the alginate mold. AW and JCHX exhibited antimicrobial potential, as evidenced by bacterial inhibition. Jeltrate or Avagel, regardless of AgNP concentration, did not demonstrate antimicrobial activity.