Yazar "Felek, Rasih" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Antibacterial activity of silver nanoparticles activated by photodynamic therapy in infected root canals
    (NLM (Medline), 2020) Aydın, Hakan; Er, Kürşat; Kuştarcı, Alper; Akarsu, Murat; Gençer, Gül Merve; Er, Hakan; Felek, Rasih
    BACKGROUND: Root canal disinfection includes mechanical, chemical and biological struggle against microorganisms (MOs). Photodynamic therapy (PDT) and nanoparticle (NP) agents may be proposed as an alternative for use against intracanal infections due to their ability to disrupt biofilm and prevent bacterial adhesion to dentin. The use of NP agents in combination with light/photosensitizer (PS) agents increases the efficiency of PDT in root canal disinfection. OBJECTIVES: The aim of the study was to evaluate the effect of light application - PDT - on the antibacterial activity of the combination of a PS agent (toluidine blue O -TBO) and an NP agent (silver nanoparticles - AgNPs) for the disinfection of the root canals inoculated with Enterococcus faecalis (E. faecalis). MATERIAL AND METHODS: In this study, concentrations of 20 ppm of TBO and 10 ppm of AgNPs, which showed the highest antibacterial activity against E. faecalis in the TBO/AgNPs combination, were used according to the preliminary studies. After instrumentation, 120 human, single-rooted, straight-canal mandibular premolars of a standard length of 13 mm were contaminated with bacteria, and experimental procedures were conducted against 21-day-old mature biofilm. The teeth were randomly divided into 5 main experimental groups: TBO/light; AgNPs; TBO/AgNPs; AgNPs/light; and TBO/AgNPs/light. Then, these main groups were divided into 2 subgroups each, according to the 2 application time periods (30 s and 60 s) (n = 10). The remaining 20 teeth constituted positive and negative control groups. The data was analyzed with the Kolmogorov-Smirnov test, one-way analysis of variance (ANOVA), Tukey's honestly significant difference (HSD) test, and the Bonferroni correction. RESULTS: The NaOCl group provided a bacterial reduction that was higher than in all other groups in a statistically significant manner. Light application on the TBO/AgNPs combination was the group that provided the highest bacterial reduction after NaOCl. CONCLUSIONS: The photoactivation of the TBO/AgNPs combination led to an increase in the effect of PDT, and it has the potential to be used as an adjunct for disinfection of the root canal system.
  • [ X ]
    Öğe
    Effect of silver ion surface coating on antimicrobial and cutting efficiencies of nickel-titanium rotary files
    (Galenos Yayincilik, 2020) Cora, Sabri; Er, Kürşat; Taşdemir, Tamer; Kiraz, Nadir; Becer, Burcu; Felek, Rasih; Er, Hakan
    Objective: Silver ions are well known to have effective antimicrobial activity against many microorganisms. This study aims to evaluate the antimicrobial and cutting efficiencies of nickel-titanium rotary file surface coated with silver ions by using the dip-coating method. Materials and Methods: A pilot study was performed before the endodontic file coating. The prepared coating solutions (silan and silver-complex systems) were applied to stainless steel plates by using the spin-coating method. The antibacterial activity of the coatings was researched against Enterococcus faecalis, which resulted in the selection of the coating solution with a 20% solid ratio and 2% silver content. Subsequently, the files were assigned to three groups based on the coating speed [group 1, 50 mm/min; group 2, 25 mm/min; and group 3, non-coated files (control)]. The cutting efficiency was evaluated by calculating the weight loss of the transparent acrylic blocks. The file surface and section was evaluated using scanning electron microscopy (SEM) and SEM-energy-dispersive X-ray spectroscopy before and after preparation. Data were statistically analysed with one-way analysis of variance and post-hoc Bonferroni test (p<0.05). Results: Significantly more debris was removed from Group 1. The cutting efficiency was not significantly different between groups 2 and 3. Groups 1 and 2 showed distinctive surface irregularities. Conclusion: The application of this antimicrobial surface coating was promising for improving antibacterial effectiveness of nickel-titanium rotary files. In addition, the thin film coating did not cause any negative effects on file cutting efficiency.