جستجوی مقالات مرتبط با کلیدواژه « Imidazolium » در نشریات گروه « پزشکی »

Statement of the Problem: The endodontically treated teeth usually suffer from the discoloration induced by endodontic materials, which can adversely affect the esthetical outcome of a treatment. This study aimed to compare the discoloration caused by the silver nanoparticles coated with imidazolium as an irrigant, sodium hypochlorite (NaOCl), and chlorhexidine gluconate (CHX). The root tips of 65 single-rooted human teeth were resected and root canal systems were chemomechanically prepared from the apical aspect. The specimens were randomly divided into three experimental (n=15) and two control groups (n=10). In the experimental groups, the substance was placed in the root canal for 30 minutes, and then washed with normal saline. Saline or blood alone was used in the control groups. The discoloration was assessed spectrophotometrically right after substance placement (T1), 1 week (T2), and 1 (T3) and 3 months (T4) after and color change values were calculated. Statistical analysis was performed using multi-sample repeated measures analysis of variance, Tukey's HSD, and Sidak tests. In T1, there was no significant difference in color change between silver nano particle, blood and CHX (p> 0.05); but these three groups had significantly more ∆E value than NaOCl and Normal Saline (p< 0.05). NaOCl and normal saline had no significant difference in T1 (p> 0.05). In T2, T3 and T4 results were the same and showed blood and silver nano particle had significantly higher color change in comparison with NaOCl, CHX and normal saline (p< 0.05). There was no significant difference between NaOCl, CHX, and normal saline in tooth discoloration (p> 0.05). There was no significant difference between silver nano particle and blood in ability of tooth discoloration (p> 0.05). Within the limitation of this study, silver nano particle material could not be suggested as an intra-canal irrigant regarding its unfavourable tooth discoloration.

The bactericidal efficiency of various positively charged silver nanoparticles has been extensively evaluated in literature, but there is no report on efficacy of various positive charged silver nanoparticles. The goal of this study is to evaluate the role of different positive electrical charge at the surface of silver nanoparticles on antibacterial activity against a panel of microorganisms and their biofilm activities and their cytotoxicity. Four different silver nanoparticles were synthesized by different methods, providing four different electrical surface charges (two ionic liquids (imidazolium and pyridinium) with 12 and 18 alkyl chain length) namely C12Im, C12Py, C18Im and C18Py, respectively. The antibacterial activity of these nanoparticles was tested against gram-positive (i.e., Staphylococcus aureus, Bacillus subtilis), gram-negative (i.e., Escherichia coli and Salmonella typhi) bacteria and Candida albicans as fungi. Disc diffusion and micro-dilution tests were used to evaluate the bactericidal activity of the nanoparticles according to CLSI methods. Also primary cytotoxicity assay of nanosilvers was assessed by MTT test.According to the obtained results, C12Py showed the highest bactericidal activity against all microorganisms tested. C18Im had the least and the C12Im had intermediate antibacterial activity. The most resistant bacteria were Escherichia coli. Different positive surface charge of silver nanoparticles was a significant factor affecting their bactericidal activity. Although the nanoparticles capped with pyridinium and 12 alkyl chains showed the highest level of effectiveness against the organisms tested, the silver nanoparticles capped with imidazolium and 12 alkyl chains were also potent against most bacterial species. Cytotoxicity of the silver nanoparticles was negligible.

The aim of this study is to evaluate the effect of a newly introduced nanosilver based irrigant on dentin roughness in comparison with three commonly used root canal irrigants.
Material and Irrigants tested were: NaOCl 5.25%, EDTA 17%, CHX 2% and newly introduced imidazolium-based silver nanoparticle (Im AgNP) irrigant at 5.8×10 -8 mol/L. Distilled water was used as control. Roots of 25 human anterior teeth were sectioned longitudinally to obtain 50 dentin samples. Roughness values were evaluated by Atomic Force Microscopy analysis on 5 groups of 10 samples after each group were treated in one of the tested irrigant solutions for 10 minutes.
Dentin roughness significantly increased from 95.82 nm (control) to 136.02 nm, 187.07 nm, 142.29 nm and 150.92 nm by NaOCl, CHX, Im AgNP irrigant and EDTA respectively. CHX demonstrated a significantly higher roughness value compared to the other irrigants tested while no significant differences were seen in NaOCl, Im AgNP irrigant and EDTA groups. (P>0.05)
Im AgNP irrigant affect physicochemical property of dentin and raised its surface roughness, thus, this irrigant could impact bacterial and restorative material adhesion to root canal dentin walls.