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This study aimed to evaluate two methods of the incorporation of nanostructured silver vanadate decorated with silver nanoparticles (AgVO 3 ) into acrylic resin and characterize the profile of early and late microbial communities in class and family taxonomic level by pyrosequencing. The specimens were made by adding different concentrations of AgVO 3 (1, 2.5, and 5%) to the heat-activated acrylic resin by two methods: vacuum spatulation (VS) and polymeric film (PF). A control group (0%) without AgVO 3 was also obtained for both methods. After 24 h and 7 days of incubation in human saliva, biofilm samples were collected, DNA was extracted, and 16S rRNA genes were sequenced by the 454-Roche sequencing platform. Seventeen classes and 51 families of bacteria were identified. The abundance of Bacteroidia, Bacilli, Negativicutes, Fusobacteria and Betaproteobacteria classes decreased after 7 days of incubation, and Clostridia, Gammaproteobacteria, and unclassified bacteria increased. The Negativicutes and Betaproteobacteria classes were more abundant when the PF method was used, and Gammaproteobacteria was more abundant when VS was used. The incorporation of 5% AgVO 3 promoted a reduction in the prevalence of Bacilli, Clostridia, Negativicutes, Betaproteobacteria, and unclassified bacteria, and increased Gammaproteobacteria. The addition of AgVO 3 to acrylic resin altered the early and mature microbiome formed on the specimen surface, and the PF method presented a more favorable microbial profile than the VS method.

The modification of endodontic sealers with nanoparticles to confer antimicrobial activity allow greater effect, with interaction at a molecular level. The nanostructured silver vanadate decorated with silver nanoparticles (AgVO 3 ) is a nanomaterial unprecedented in dentistry for this application. This study incorporated the AgVO 3 into three endodontic sealers of different compositions and evaluate the cytotoxicity and release of compounds. The groups of commercially available AH Plus, Sealer 26, and Endomethasone N and groups of the same sealers with incorporated AgVO 3 (at concentrations 2.5, 5, 10%) were prepared, and extracts of the specimens were obtained for 24 h. The cell viability (cytotoxicity) of human gingival fibroblasts (HGF) was assessed after 24 h, 7 and 14 days. Silver (Ag + ) and vanadium (V 4+ /V 5+ ) ion release was quantified after 24 h by ICP-MS. Data were analyzed by Kruskal-Wallis and Dunn's post-hoc (α = 0.05). The cell viability was inversely proportional to treatment time. The Sealer 26 and Endomethasone N groups were cytotoxic for HGF cells, regardless of the incorporation of the AgVO 3 (p > 0.05), and the incorporation reduced cell viability of AH Plus (p < 0.05). The release of ions was proportional to the concentration of AgVO 3 . AH Plus released more Ag + ions, and Sealer 26 and Endomethasone N releases more V 4+ /V 5+ ions. In conclusion, it was not possible to confirm the influence of AgVO 3 on HGF cell viability to Sealer 26 and Endomethasone N, however, nanomaterial influenced cell-viability to AH Plus, so the commercial sealers can be cytotoxic in synergy with the nanomaterial. The release of Ag + and V 4+ /V 5+ was proportional to the AgVO 3 incorporated.

Purpose: To evaluate the antimicrobial activity and physico-mechanical properties of an irreversible hydrocolloid in which nanostructured silver vanadate decorated with silver nanoparticles (AgVO 3 ) was added at various concentrations (0% - control, 2.5%, 5%, and 10% by weight)., Materials and Methods: The agar diffusion method (n = 10) was used to evaluate the inhibitory effect on the following species: Streptococcus mutans, Staphyloccocus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. The gelation time, flow capacity and plastic deformation were verified (n = 10). The data were analyzed using the Kruskal-Wallis test followed by the Dunn post-test, or via one-way ANOVA with multiple comparisons with a Bonferroni adjustment depending on the distribution (α = 0.05)., Results: All percentages of the nanomaterial were able to promote the antimicrobial activity of a hydrocolloid, with the formation of an inhibition zone (p < 0.05). In general, there was a dose-dependent effect on antimicrobial activity: higher concentrations of the nanomaterial promoted greater action except in the cases of P. aeruginosa (p < 0.001; F = 51.74) and S. aureus (p < 0.001), where the highest inhibition was for the 2.5% group. No difference was found in the gelation time when the control was compared with the groups with AgVO 3 (p > 0.05). The difference was between the 5% and 10% groups (p = 0.007), and the latter promoted an increase in time. The flow capacity of the hydrocolloid with 5% of AgVO 3 was significantly lower when compared with the control (p = 0.034). The AgVO 3 influenced the plastic deformation (p < 0.001) in such a way that concentrations of 5% (p = 0.010) and 10% (p < 0.001) promoted an increase in this property when compared with the control., Conclusions: AgVO 3 can be incorporated into an irreversible hydrocolloid as an antimicrobial agent without promoting adverse effects on physical-mechanical properties when used in concentrations of 2.5%., (© 2019 by the American College of Prosthodontists.)

Objectives: This study characterized the microbial diversity of formed biofilm on the surface of acrylic resins modified with nanostructured silver vanadate decorated with silver nanoparticles (AgVO 3 ) after incubation in human saliva., Design: Resin specimens prepared with AgVO 3 at concentrations 0%, 1%, 2.5%, and 5% by either vacuum mixing or polymer solubilization were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). After 24 h and 7 days of saliva incubation, biofilm samples were collected from the surface of the specimens. The 16S rDNA genes were amplified, sequenced with the 454-Roche next-generation sequencing platform and analyzed to identify the Operational Taxonomic Units at the genus or higher level., Results: Significant differences in the dispersion pattern of the nanoparticles were observed among the two different methods of AgVO 3 incorporation. In the microbiological analysis, a total of 103 genera and 7 more inclusive taxa, representing the phyla Bacteroidetes, Firmicutes and Proteobacteria were identified colonizing resin surfaces. The incorporation method of the AgVO 3 had little to no significant effect on the microbiota of samples. Significant time and concentration-dependent responses to AgVO 3 caused changes in the taxonomic profile at the phylum and genus level., Conclusions: The results show differences in relation to the microbial diversity of modified resins during the initial phase of biofilm maturation. The incorporation of AgVO 3 seems to significantly affect the colonizing microbiota., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

This study analyzed nanostructured silver vanadate (AgVO3) films on certain substrate surfaces found in dental implant devices in order to see if these films promote antimicrobial activity. Enamel and glaze vehicles were used to apply the nanomaterial (0.0% [control], 2.5%, 5.0%, and 10.0% concentrations) on 3 substrates (280 specimens per substrate): polytetrafluoroethylene (PTFE), polyacetal, and acrylic resin. An agar diffusion method was performed in triplicate to determine the antimicrobial activity against 8 microorganisms. Physical behavior and morphologic properties were also analyzed. The growth of Pseudomonas aeruginosa, Escherichia coli, Streptococcus mutans, Enterococcus faecalis, and Staphylococcus aureus was inhibited with the application of AgVO3. For Candida albicans, Porphyromonas gingivalis, and Prevotella intermedia, no antimicrobial activity was observed. Except for S mutans, the type of substrate did not influence the microbiologic results. The glaze showed greater antimicrobial efficacy against S aureus, E faecalis, and S mutans than did the enamel vehicle (P < 0.05). Films with 10% AgVO3 showed greater antimicrobial activity (P < 0.05). The choice of substrate or vehicle did not influence the surface roughness (P > 0.05); however, the application of 10% AgVO3 caused greater surface change (P < 0.05). The application of the nanomaterial did not influence the surface hardness of substrates when compared with the control group (P > 0.05). The use of the glaze as a vehicle provided higher hardness values (P < 0.05).

Objectives: This study evaluated the release of ions and the cytotoxicity of acrylic resins incorporated with silver vanadate decorated with silver nanoparticles (AgVO 3 )., Background: The inhibition of the accumulation of microorganisms on the resins is critical in preventing diseases. However, the hypothesis is that the release of ions from the incorporation of AgVO 3 may be important in biocompatibility., Materials and Methods: Specimens of autopolymerising (AP) and heat-polymerising resin (HP) with AgVO 3 were prepared and immersed in culture medium. The release of silver ions (Ag) and vanadium (V) was evaluated by mass spectrometry with inductively coupled plasma (ICP-MS) (n=9) and the cell viability of fibroblasts L929 by MTT (3-[4,5-dimethylthiazol- 2yl]-2,5-diphenyltetrazolium bromide) (n=12). The results were evaluated with analysis of variance (ANOVA), Tukey and Pearson correlation test (α=.05)., Results: The groups containing AgVO 3 presented a difference in relation to the control (0%) regarding the release of Ag and V (P<.0001). All groups showed a reduction in L929 viability when compared with the cellular control (100%) (P<.0001). In comparison with the control resins for HP, a reduction in the metabolism of cells occurred starting at 2.5% and for AP at 5% (P<.0001). A positive correlation was found between the concentration of AgVO 3 and the ion release, and a negative between the ion release and the cell viability., Conclusions: Significant numbers of Ag and V ions were released from resins with higher concentrations of AgVO 3 , presenting cytotoxicity for cells, suggesting that the use of low concentrations is indicated to avoid risks to patients., (© 2017 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.)