فهرست مطالب kiomars nazari moghadam

Cleaning and shaping is one of the most important stages in endodontic treatment. Single-file systems save time and reduce the risk of transmission of pathogens. This in vitro study was aimed to compare the rate of canal transportation after the preparation of the stimulated resin root canal with two single-file systems, namely Waveone and Reciproc.
Thirty stimulated resin root canal blocks with size 8/0. 02 K file were randomly divided into two study groups. The preparation in Group A and Group B was performed using Reciproc and Waveone files, respectively. Pre and post- preparation photographs were taken and the images were superimposed to evaluate the inner and outer wall’s curvature tendency at three points (apical, middle and coronal) using AutoCad pragram. Data were analyzed using T-test.
Based on the results, the degree of transportation in the inner and outer walls of the canal was less at the level of 3 millimeters (P0.05).
Waveone showed better performance in the middle third of canal and this system maybe recommended.

Dental materials that are used for fixation in deciduous pulpotomy have adverse reactions such as toxicity and carcinogenic and mutaginic effects. Severe efforts are focused on substitution of these materials with safer ones. It has been reported that herbal medicines have useful clinical effects. It has been shown that the SUAB1 and SUAB2 had a lower cytotoxicity than formocresol.To compare the in vivo histocompatibility of SUAB1 and SUAB2 in subcutaneous tissue of rat. The study design was descriptive- analytical. Twenty-one rats with an average weight of 350 grams were used. SUAB1 and SUAB2 were separately placed in polyethylene tubes and implanted in the dorsal subdermal tissue. After intervals of one, two, and four weeks, animals were sacrificed. The implant materials with surrounding tissue were removed and collected in 10% buffered formalin solution for histopathologic evaluation. Capsule thickness, inflammation intensity, angiogenesis, necrosis and calcification were studied on paraffin-embedded sections. Data were analyzed by SPSS software (version 11.5). The Friedman and kruskall-wallis statistical tests were used. Statistically significant difference in capsule thickness, intensity and extent of inflammation, angiogenesis, necrosis and calcification was observed between SUAB1 and SUAB2 groups. Capsule thickness, intensity of inflammation and calcification was higher in SUAB1 group than SUAB2.

Silver nanoparticles, the new generation of antimicrobial agents, have been employed in different applications. Eradication of bacterial strains such as Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa by nanosilver is considerable. In the other hands, macrophages, the most important immune cells in nanoparticles clearance in semi-open human body interfaces determine nanosilver fate.In this study, colloidal nanosilver toxicity on macrophages and three bacterial strains was assessed so as to determine effective antibacterial concentrations without toxic effect on macrophages for harmless usage of nanosilver.

The bactericidal effect of silver nanoparticles was assessed based on minimum inhibitory concentration (MIC) of nanoparticles. The effect of silver nanoparticles on macrophages measured based on MTT assay in vitro.

The MIC of colloidal nanosilver was equal to 1/56 part per million (ppm) for E. coli strain and S. aureus strain but the MIC of colloidal nanosilver was equal to 3/125 ppm for P. Aeruginosa. Both of these MICs and the corresponding MBCs were the same. Maximum concentration of colloidal nanosiver which did not kill macrophage cells completely after 24 h was 2 ppm but non-toxic maximum concentration of nanosilver for macrophage cells compared to the control group was 0.5 ppm.

Accordingly, concentrations of nanosilver higher than 2 ppm are toxic for macrophages and lower than 0.5 ppm concentration has not any antimicrobial effect. Therefore, precaution must be taken for the usage of large concentrations of nanosilver. Approaches to truths pertaining to complex nanosystems necessitate accomplishment of in vivo experiments and comparison of their result with that of in vitro.