Incorporating Antimicrobial Nanomaterial and its Effect on the Antimicrobial Activity, Flow and Radiopacity of Endodontic Sealers

OBJECTIVE: This preliminary study aimed to evaluate the antimicrobial activity, flow and radiopacity of endodontic sealers with nanostructured silver vanadate decorated with silver nanoparticles (AgVO3). METHODS: The minimum inhibitory concentration (MIC) of AgVO3 was evaluated against Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli. Specimens were prepared from the following endodontic sealers: AH Plus (DENTSPLY DeTrey GmbH, Konstanz, Germany), Sealapex (Sybron Endo, Orange, CA, USA), Sealer 26 (DENTSPLY, Petrópolis, Brazil) and Endofill (DENTSPLY, Petrópolis, Brazil), with concentrations of 0%, 2.5%, 5% and 10% of AgVO3. Agar diffusion was used to evaluate the materials after 48 hours and 7 days (n=6). Flow (n=6) and radiopacity (n=9) were evaluated. The data were analysed by analysis of variance (ANOVA) and the Tukey honestly significant difference (HSD) (α=0.05). RESULTS: The MIC of AgVO3 was 500 μg/mL for E. faecalis and 31.25 μg/mL for P. aeruginosa and E. coli. The AgVO3 did not influence the antimicrobial activity of AH Plus against E. faecalis (P>0.05) but did promote this activity for Sealapex (P<0.01). Moreover, this activity increased for Endofill from 2.5% and for Sealer 26 from 5% (P<0.05). Against P. aeruginosa, only AH Plus and Endofill 10% inhibited zone formation (P<0.01). The antimicrobial activity of Endofill increased from 2.5% against E. coli (P<0.01). Sealapex 5% and 10% (P<0.01), Sealer 26 10% and AH Plus promoted antimicrobial activity against E. coli. An increase in the zone of inhibition occurred between 48 hours and 7 days in the Sealapex 10% and Endofill 5% groups against E. coli. The flow of AH Plus and Endofill decreased with the increase of AgVO3 (P<0.05), and the flow of Sealer 26 and Sealapex was not affected (P>0.05). The radiopacity of AH Plus increased with AgVO3 (P<0.05). Endofill 5% and 10% did not differ from the control Endofill (P>0.05). The incorporation of AgVO3 did not influence the radiopacity of Sealer 26 (P>0.05). The incorporation of 2.5% and 5% AgVO3 reduced the radiopacity of Sealapex (P<0.05). CONCLUSION: Adding AgVO3 may increase the antimicrobial effect of endodontic sealers without major changes in their physicochemical properties.