Evaluation of endodontic sealers incorporated with nanostructured silver vanadate decorated with silver nanoparticles for genotoxic potential, antimicrobial and physicochemical properties

Author(s)

Ana Beatriz Vilela Teixeira

• Document type: Doctoral Thesis
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Ribeirão Preto (PCARP/BC)
• Defense date: 2019-12-13

Examining board members

Andréa Candido dos Reis; Rossana Pereira de Almeida; Diana Gabriela Soares dos Passos; Daisy Maria Fávero Salvadori

• Advisor: Andréa Candido dos Reis

Abstract

In this work, the nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) was incorporated into three endodontic sealers of different compositions, to promote antimicrobial activity, aiding in the reduction of microorganisms in root canals after endodontic treatment. The AgVO3 was incorporated into commercial sealers AH Plus, Sealer 26 and Endomethasone N, at concentrations of 0% (without AgVO3), 2.5%, 5% and 10% (in mass), and evaluated: (1) the antimicrobial activity of freshly mixed (n=10) and set sealers (n=9) against Enterococcus faecalis; (2) the genotoxic potential for human gingival fibroblasts (HGF) treated with extracts from the experimental groups (24h and 7 days), through cell viability assay zero hour (T0) and 24 hour (T24) after treatment, cell death assays by apoptosis or necrosis, and genotoxicity (n=3); (3) the physicochemical properties of surface topography and chemical composition, solubility (n=9), pH (n=10) and silver (Ag+) and vanadium (V4 +/V5 +) ions release (n=3). The data were evaluated by ANOVA and Tukey HSD post-hoc for the antimicrobial activity of set sealers, solubility, and genotoxic assays; Kruskal-Wallis and Dunn post-hoc for the antimicrobial activity of freshly mixed sealers and ion release; Friedman\'s two-way analysis of variance for pH (&alpha;=0.05); and descriptive analysis for surface topography and chemical composition. The results showed that the freshly mixed sealers inhibited the growth of E. faecalis (p>0.05). The set sealers Sealer 26 (5 and 10%) and Endomethasone N (2.5, 5 and 10%) presented higher antimicrobial activity (p<0.05). HGF viability soon after treatment (T0) was higher than at 24 hours after treatment (T24) (p<0.05). A synergy between the sealers and nanomaterial components was observed in reducing viability, which occurred in the highest AgVO3 concentrations and the longest extract (p<0.05). AgVO3 did not induce DNA breaks (p>0.05) and apoptosis in HGF (except AH Plus 10% - extract 7 days, p<0.05). The incorporation altered the atomic proportions of the sealer\'s components and the topographic distribution. The solubility of the AH Plus and Sealer 26 was not affected by the nanomaterial (p>0.05), and Endomethasone N 5% showed a reduction of the solubilization (p<0.05). The AH Plus groups showed acidic pH, and Sealer 26, basic pH after 30 days. Endomethasone N 5 and 10% showed a statistical difference in pH compared to 0% (p<0.05). The release of Ag+ and V4+/V5+ was higher in 24 h and proportional to the concentration of AgVO3 incorporated. The AH Plus groups released more Ag+, and Sealer 26 and Endomethasone N, more V4+/V5+. It was concluded that AgVO3 incorporated in the sealers evaluated promotes antimicrobial activity, mainly to the Sealer 26 (5 and 10%) and Endomethasone N (2.5, 5 and 10%) groups; does not induce DNA breaks and apoptosis in HGF (except AH Plus 10% - extract 7 days), and influences cytotoxicity in synergy with sealers components; promotes changes in the atomic percentage and topography of the sealers; influences the solubility and pH of Endomethasone N 5% and 10%; and promotes greater ion release within 24 h. (AU)

• FAPESP's process: 17/04667-0 - Evaluation of endodontic sealers incorporated with silver vanadate nanostructured decorated with silver nanoparticles for toxicity, antimicrobial and physicochemical properties
• Grantee: Ana Beatriz Vilela Teixeira
• Support Opportunities: Scholarships in Brazil - Doctorate