The synthesis of nano silver-graphene oxide system and its efficacy against endodontic biofilms using a novel tooth model

• Published in: Dental materials 2019-11, Vol.35 (11), p.1614-1629
• Main Authors: Ioannidis, Konstantinos, Niazi, Sadia, Mylonas, Petros, Mannocci, Francesco, Deb, Sanjukta
• Format: Article
• Language: English
• Subjects: Antiinfectives and antibacterials; Biofilm; Biofilms; Chlorhexidine; Confocal microscopy; Data analysis; Dental Pulp Cavity; Dentistry; Diameters; Disinfection; Disruption; Edetic acid; Endodontics; Energy transmission; Enterococcus faecalis; Ethylenediaminetetraacetic acids; Graphene; Graphene oxide; Graphite; Irrigation; Mathematical models; Metal Nanoparticles; Microorganisms; Morphology; Nanoparticles; Root canal; Root canals; Scanning electron microscopy; Scanning microscopy; Scanning transmission electron microscopy; Sheets; Silver; Silver nanoparticles; Sodium; Sodium hypochlorite; Teeth; Transmission electron microscopy; Ultrasonics; Variance analysis; Viability; X-ray spectroscopy
• ISSN: 0109-5641; 1879-0097
• DOI: 10.1016/j.dental.2019.08.105

•Word count was performed for all highlights. They did not exceed 125 characters (with added space).•Non-contacting surface profilometry is important for the standardisation of artificial lateral canals in tooth models.•Silver nanoparticles were successfully synthesized on an aqueous graphene oxide matrix.•The antimicrobial efficacy of Ag-GO was comparable to 2% CHX and 1% NaOCl.•Ultrasonic activation selectively improved the antimicrobial efficacy of the Ag-Go in lateral canals. The deleterious caustic effects of sodium hypochlorite (NaOCl) as a root canal irrigant makes it imperative that alternative methods are developed for root canal disinfection. The purpose of this study was to examine the antimicrobial efficacy of silver nanoparticles (AgNPs) synthesized on an aqueous graphene oxide (GO) matrix (Ag-GO), with different irrigant delivery methods to enhance the disinfection regimen, using a novel ex vivo infected tooth model. AgNPs were prepared by reducing AgNO3 with 0.01M NaBH4 in presence of GO. Elemental analysis was performed with scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) and scanning transmission electron microscopy (STEM) was used for size and morphology analysis of GO and Ag-GO. Nutrient stressed, multi-species biofilms were grown in prepared root canals of single-rooted teeth. The irrigants used were sterile saline, 1% and 2.5% NaOCl, 2% chlorhexidine gluconate (CHX), 17% EDTA and an aqueous suspension of 0.25% Ag-GO. The antimicrobial efficacy of the irrigants were performed with paper point sampling and measurement of microbial counts. The biofilm disruption in dentine tubule surfaces was analysed with confocal laser scanning microscopy (CLSM). The acquisition of total biovolume (μm3/μm2) and biofilm viability was performed using software BioImage_L. Two-way analysis of variance (ANOVA) with post hoc Tukey tests was used for data analysis with level of statistical significance set at P