فهرست مطالب golbarg kolahi ahari

Different chelators may be used during root canal treatment, offering various advantages including lubricant effect inside the canal and smear layer removal. However, chelator residues in narrow root canals can lead to apical microleakage. The aim of this in-vitro study was to compare apical microleakage following the use of three root canal chelators via fluid filtration method in root canals instrumented with ProTaper rotary system.
Sixty-eight distobuccal canals of maxillary first molars were randomly divided into six groups of four experimental (n=15) and a positive and a negative control group (n=4). In groups one to three, RC-Prep, 17% EDTA and Glyde File Prep were used as chelators, respectively and sodium hypochlorite (NaOCl) was used as irrigant in all groups except for group four. In group four, root canals were instrumented without chelators and only saline was used for irrigation. Root canals in all groups were prepared using ProTaper rotary system up to F2 file and filled using cold lateral condensation technique with gutta-percha and AH26 sealer. Apical microleakage was assessed by fluid filtration method. The data were subjected to Kruskal-Wallis test.
No significant differences were noted among the experimental groups regarding apical microleakage (p>0.05). However, preparations with RC Prep NaOCl and Glyde File Prep NaOCl yielded the highest and the lowest values of apical microleakage, respectively.
Use of different chelators did not cause statistically significant difference in apical microleakage of root canals.

The term “Conjugated linoleic acid (CLA)” refers to a class of linoleic acid isomers. During the recent years, scientists have particularly regarded this fatty acid as a functional food. However, the findings of the studies in health benefits of CLA are inconsistent. The purpose of this study was to review the articles that investigated the effects of CLA on different aspects of health.
Controlled clinical trials including human, animal and in vitro studies having been published since 2000 till 2016 in English were searched in PubMed, ISI Web of Science, Scopus and Science Direct databases. Sixty four articles were finally selected to review the results.
Findings of the researche indicated that CLA has an anticarcinogenic function. In some studies CLA had beneficial effects on bone metabolism and it is suggested that CLA may be useful in prevention and treatment of osteoporosis. In addition supplementation with CLA in animal and human models leaded to reduction in body fat mass and improvement in insulin resistance and lipid profile. However, some studies reported adverse effects of CLA intake including accumulation of fat in tissues, elevation of lipid peroxidation and inflammation markers.
Although benefits of CLA intake are shown in several studies, side effects of this fatty acid are reported in other researche. It is necessary to design further studies to more precise investigation of the benefits and risks of CLA.

Food insecurity refers to the limited or unreliable access to sufficient quantity and quality of food or the restricted opportunities to obtain food through socially approved ways which turning into the major health concern , has been the cause of so many chronic diseases such as obesity.
To achieve the present study’s objectives certain data bases as google scholar, Science Direct, PubMed , Scopus, Ovid, Eric, CINAHL, EMBASE, Cochrane Library and PsychInfo concurrent with the key words "food insecurity", "food hardship", , "hunger", " food security ", "obesity", "race","minority",poverty " ," food assistance " and also various other related words and phrases have comprehensively been searched since 1995 till 2016. The main criterions for the articles to be enlisted in the study were availability of the full text, English standing as the source language of the article, and the publication date being between 1995 and 2016.
Food insecurity and the obesity prevalence among the members of the families strongly depend on certain factors as the age, sex, marital status, stressors, income levels, ethnicity and race. After reviewing the articles enlisted in the current study regarding the risk of obesity among various age and sex groups, diverse results were obtained.
Due to similar affecting agents on the emerge of food insecurity and the obesity prevalence, there seems to exist direct associations between food insecurity and the obesity which could be obviously recognized among most of the age and gender groups.

Themajor objective of root canal treatment is to disinfect the entire root canal system, which requires that all contents of the root canal system be eliminated as possible sources of infection. This goal may be accomplished using mechanical instrumentation and chemical irrigation. To reduce or eliminate bacteria various irrigation solutions have been applied during the treatment. This research aimed to determine thecytotoxicity of calcium hydroxide powder as compared with calcium hydroxide reinforced with chlorhexidine. This study was carried out using on experimental-laboratory method on L929 fibroblasts based on cell culture and the direct effect of materials on cell line culture. The material to be tested were evaluated every 1,12,24,48and 72 hours by MTT(Metheyltetrazilium bromide) test.In this study L929 cells which not treated with any materials were used as negative control.The data related to the given materials were read by Elias(enzyme-linked immunosorbent assay) instrument. And then were analyzed with SPSS software and one-way ANOVA. Both materials in 0.016 up to 0.00025 concentrations suppressed proliferation. There was a significant difference in various dilutions and different time periods (1,12,24,48,72 hours)(p<0.05).Calcium hydroxide reinforced with chlorhexidineand calcium hydroxide powderin 0.016 concentration and 72 hour showed 75% and 45% cell cytotoxicity,respectively. Cell cytotoxicity of calcium hydroxide reinforced with chlorhexidine is more than that of other materials. Since calcium hydroxide reinforced with chlorhexidine have a higher antimicrobial effect,it is cautiously recommended as a sealing material between treatment(provided that it slightly penetrate to periapical tissues)

The aim of this study was to compare the changes that occur in the danger zone (DZ) after preparation of curved mesiobuccal (MB) canals of mandibular first molars with WaveOne instruments in two different movements [reciprocation (RCP) and counter-clockwise rotation (CCWR)] by means of cone-beam computed tomography (CBCT). Methods and Materials: MB canals of 30 mandibular molars were randomly divided into 2 groups (n=15); WaveOne/RCP and WaveOne/CCWR. Pre- and post-instrumentation CBCT images were assessed for changes in the dentin thickness in DZ (2 and 4 mm below the highest point of the root furcation) in both groups. Data was analyzed using the repeated measures ANOVA test. There was no statistically significant difference between two experimental groups in terms of remaining dentin thickness at 2 and 4 mm levels below the highest point of the furcation (P>0.05). The efficacy of WaveOne instrument on changes of the dentin thickness in the DZ was not affected by different file movements.

The aim of this in vitro study was to evaluate the effect(s) of three canal lubricants i.e. sodium hypochlorite, RC-Prep as the paste form of ethylenediaminetetraacetic acid (EDTA) and aqueous EDTA, on the occurrence/incidence of fracture, deformity and metal slivering of ProTaper rotary instruments. A total of 120 mesial canals (i.e. mesiobuccal and mesiolingual) of first mandibular molars or buccal canals (i.e. mesiobuccal and distobuccal) of first maxillary molars, with curvatures of 10-20 degrees were selected and randomly divided into three groups of forty samples each. These selected canals all had approximate 19-21 mm working length and apical diameter equal to a #15 K-file. In each group, the root canals were prepared using ProTaper rotary instruments with an electric motor using one of the three aforementioned irrigants. Subsequently, samples were compared to each other at different magnifications (16×, 20×, 40× and 57×) for any fracture, deformity or metal slivering, by the Cox regression analysis. The fractures rate of samples in RC-Prep group was significantly higher compared to other groups (P=0.01). No evidence of instrument deformity was detected in any groups. A statistically significant reverse relation between metal slivering and instrument fracture was observed. Application of aqueous EDTA and/or sodium hypochlorite as intracanal lubricants caused less fracture of ProTaper instruments compared to canal lubrication with RC-Prep.

Antibacterial activity is one of the desirable properties of an ideal sealer. This study aimed to compare the antimicrobial effect of three different sealers, i.e. resin (AH26), calcium hydroxide (Apexit) and zinc oxide eugenol (ZOE) based sealers. Direct contact test with agar diffusion was used in this in vitro study. The freshly mixed sealers were AH26, Apexit and pure ZOE. They were prepared according to manufacturer’s instruction and placed in prepared wells of 30 agar plates inoculated with Streptococcus (S) mutans and Prevotella (P) melaninogenicus (15 samples for each microorganism). All plates were incubated for 7 days (196 hours) at 37˚C under anaerobic conditions, and zones of inhibition were measured after 3 days, 5 days and 7 days. The data were analyzed using Kruskal-Wallis and Friedman tests. In all determined intervals, the antibacterial activity of AH26 was significantly greater than other test materials (P<0.001). ZOE sealer had moderate effect on test microorganisms, whilst Apexit showed the lowest antibacterial activity on S. Mutans and no antibacterial activity on P. melaninogenicus. The ascending sequence of bacterial growth inhibition zones was as AH26>Pure ZOE>Apexit.