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Background: Based on biochemical properties, Enterobacter cloacae represents a large complex of at least 13 variant species, subspecies, and genotypes that progressively identified as the most species causing hospital-acquired infections. The aim of this study was to determine the relevance between phylogenetically related strains within the E. cloacae complex and the frequency of urinary tract infection caused by them
Methods: A 268-bp fragment was obtained from hsp60 gene for 50 clinical E. cloacae isolates from urine cultures of inpatients that admitted to six hospitals in Tehran, Iran during December 2012 to November 2013. The 107 nucleo de sequences were analyzed and the evolutionary distances of sequences were computed and neighbor-joining tree was calculated
Results: It showed that all of the genetic clusters have not an equal involvement in pathogenesis of urinary tract infections. Three superior clusters were found, together representing more than two third [80%] of the isolates [cluster VI with 25 members; clusters III and VIII with 9 and 6 members, respec vely] andsome genetic clusters were absent [IV, X, XII, and xiii], some of which are supposed to be associated with plants and no human infection has been reported
Conclusions: This study, for the first time, reports the unequal contribution of E. cloacae complex subspecies and clusters in urinary tract infections in Iran and together with studies from other countries suggest that the subspecies of E.hormaechei subsp. Oharae is the most prevalent E. cloacae complex subspecies regardless of country under study
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Objective: Fiber-reinforced composite [FRC] posts have recently become more popular for restoring endodontically treated teeth because of providing esthetics, better stress distribution and lower risk of root fracture. Resistance against tensile forces dislodging the post from the root canal is a prerequisite for these posts. This study aimed to evaluate the tensile retention [strength] of intracanal glass fiber posts produced by three manufacturers
Methods: In this interventional study, the crowns of 30 sound human maxillary central incisors were cut at the cementoenamel junction and the roots were endodontically treated. Post space was prepared to a length of 10mm and the specimens were divided into three groups of 10. HtCo, Anthogyr and Svenskposts were used in groups 1, 2 and 3, respectively. The posts were cemented with Panavia F2 resin cement according to the manufacturer's instructions. Specimens were then immersed in water at 37[degree sign]C for 30 days and were then subjected to 7500 thermal cycles between 5- 55[degree sign]. Intracanal tensile retention [strength] was measured at a crosshead speed of 0.5 mm/min. Data were analyzed using one-way ANOVA at p<0.05 level of significance
Results: The mean retention was 188.53 [15.43], 183.81 [16.37] and 192.19 [17.50] N in Htco, Anthogyr and Svensk posts, respectively. Statistical analyses showed no significant difference in this regard among groups [p=0.111]
Conclusion: Within the limitations of this study, retention of HtCo glass fiber posts in the root canals was similar to that of two other posts
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Objective: Different educational tools are now commonly used in universities worldwide such as illustrations, audio and videotapes, etc. This study aimed to compare the efficacy of educational film and clinical demonstration for instruction of Fiber-Reinforced Composite [FRC] post restorations to dental students in Department of Restorative Dentistry
Methods: This interventional study was conducted on 70 fifth year dental students in Mashhad University. Students were divided into two groups. Group 1 students watched live demonstration of a treatment procedure [FRC post restoration] while group 2 watched the educational film of the same procedure. Both groups participated in a post-test. Also, students' perspectives were sought via a questionnaire. Data were analyzed using SPSS, Student's t-test and Chi-square test
Results: The mean post-test score of group 2 students [educational film] was greater than that of group 1 students [clinical demonstration] and the difference in this respect between the two groups was statistically significant [p=0.008]. Considering the score of 7 as an acceptable score, 44 students gained scores 7 or higher; out of which, 16 were in group 1 [clinical demonstration] and 28 were in group 2 [educational film]. The difference in this regard between the two groups was statistically significant [p=0.003]. Most students preferred watching the educational film to the crowded clinical demonstration sessions
Conclusion: Watching the educational film yielded greater test scores than the clinical demonstration
ABSTRACT
The aim of this study was to evaluate the fracture strength of restored teeth with three different types of E glass-fiber posts after thermo-mechanical loading. Sixty extracted upper central incisor human teeth, with similar size, were selected and divided into three groups [n=20]. Endodontic treatment was done in all groups and crowns were sectioned from 2 mm above CEJ. Then one type of posts in each group [Anthogyr, Svensk, Hetco] cemented using Panavia cement and the crowns were restored with a composite. The specimens in each group were thermocycled for 6000 cycles [5-55°C] and subjected to 1200000 cycles of mechanical loadiong in an artificial mouth machine. Then the fracture strength was measured and data were analyzed using ANOVA and T-student test [alpha=0.05]. The mean fracture strengths in Hetco group before and after thermomechnical loading were 581.098 +/- 192.742 N and 564.74 +/- 213.59 N, in Anthogyr group were 664.358 +/- 135.878 N and 629.12 +/- 390.3 N and, in Svensk group were 780.258 +/- 379.133 N and 779.84 +/- 282.59 N, respectively. There was no significant difference between groups and also there was no significant difference in each group before and after thermo-mechanical loading [P>0.05]. Restored teeth with Hetco fiber glass post were similar in terms of the fracture strength with that of two other posts after thermo-mechnical loading
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Extended-spectrum beta-lactamase [ESBLs] producing bacteria are issued as a serious problem considering their ability to hydrolyze most of beta-lactam antibiotics. The outbreak of infections derived by ESBL-producing enterobacteriaceae is increasing throughout the world. Therefore, this study aims to determine a pattern of antibiotic resistance and investigate the extended-spectrum beta-lactamases production of enterobacteriaceae isolates separated from clinical specimens. In this study, 170 various strains of enterobacteriaceae isolated from clinical specimens in teaching hospitals of Arak cultured and identified applying standard methods during one year [2010-2011]. The antibiotic resistance of isolates was investigated through disk Agar diffusion according to CLSI criteria. The resistant isolates against ceftazidime and cefotaxime antibiotics were studied through the combined disk test for the final confirmation of ESBL-production. The minimum inhibitory concentration was determined through micro broth dilution. In this study, the resistance rate of various strains of enterobacteriaceae against amoxiclav, cefotaxime, ceftriaxone, ceftazidime, cefoxitin, cefotetan, meropenem and imipenem were respectively, 91.1%, 70%, 68.8%, 62.9%, 28.2%, 11.1%, 11.1% and 1.7%. Among 125 resistant enterobacteriaceae isolates against ceftazidime or cefotaxime, 108 isolates [86.4%] had ESBL-positive phenotype and 17 isolates [13.6%] had ESBLnegative phenotype. The MICs of the resistant isolates were indicated within a range of 16 to 512 micro g/ml for ceftazidime and 64 to 512 micro g/ml for cefotaxime. According to the results of this study, imipenem is the most effective antimicrobial antibiotic. On the other hand, the present study indicates that the bacteria within the family of ESBL producing enterobacteriaceae are highly prevalent among the patients. The increase in rate of such cases is often resulted by irrational antibiotic prescription. Application of new antimicrobials, limitation of the use of antimicrobial factors and increasing the utilization of infection control tools are all required in order to solve this problem.
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Evaluation of educational processes in different fields of medical sciences has high priority because of the important role in professional experts training. Dentistry, as an important field of medical sciences, requires scientific and professional skills. Surveying the opinions of dental students as the main actual consumers of the education is one of the most popular methods to evaluate the quality of dental clinical education. The aim of this study was to evaluate the students'perception about clinical education and examination in Mashhad dental school in 2009. All students at fourth, fifth and sixth grades of Mashhad dental school in 2009, were participated in this cross-sectional study. A questionnaire was designed in this study to assess clinical education. The validity and reliability of the questionnaire was proved. The results were presented in tables. Kruskal Wallis test was used to compare between groups [a=0.05]. The results showed that the students' perception, in most areas of education, performance of clinical faculty, clinical facilities, clinical assessment, evaluation of students' activities by professors, nurses cooperation and educational purposes was positive while there were some deficiencies particularly in course selection, and monitoring student's work in a few departments. There was no difference between clinical education and evaluation of departments in dental school in students' points of view. It can be concluded that revision of school activities and review of curriculum for possible changes, providing equipment and materials required in the clinical environment is suggested
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Dental students are exposed to clinical environmental stresses in addition to educational environmental stresses. If psychological stressors become chronic and/or remain untreated, they result in psychological and physical symptoms. There are few studies about stress and dental students in our country. The aim of this study was to assess stress level and related factors sorted according to the academic year and gender, among dental students of Mashhad University of Medical Sciences during 2008-2009.This study was a description-analytical and cross-sectional study. In this research two questionnaires were used concurrently and the information obtained was analyzed by the SPSS software. 52% of students showed abnormal levels of stress. Students of fourth academic year showed the highest level of stress. Stress levels in two genders were not significantly different. It was also characterized that university stressors played a more significant role in stress level than non-university stressors. Based on the results of this study, and the findings of, high levels of stress among dental students as well as the harmfulness of high levels of stress, greater attentions must be given to this issue by the uthorities. Furthermore, the forth year students who have recently entered the clinic, are in the greatest need of help
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Psychologists have observed that during the student career what have the most effect on academic performance status are the general study skills. One important reason that some students do not achieve desired results from their efforts is lack of study skills. It is useful for education managers to have information about student's capabilities. The purpose of this research was to evaluate study skills among students of Mash had Dental School in the academic year of 2008-2009. One hundred and ninety students from Mashhad Dental School participated in this cross sectional descriptive study. A questionnaire which proved to be valid and reliable was used for data collection. Data were analyzed with SPSS software and described with descriptive statistics. Our research findings showed that students do not have enough knowledge of study skills. The greatest shortcomings were in the fields of reminding and remembering the subjects, concentration and time management. Study resources of most students for final examination were fascicles and during the semester were textbooks. The students also do not insist on review of learned contents. 58% of students had efficient methods, but 38% did not have a good efficient method. The students' resources and techniques of studying lack the desired quality. This should be considered by education department officials. It is essential to schedule training programs for students to enhance their study skills. Teaching these skills and improving study habits by carrying out relevant workshops for first-year students can help to improve their learning
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The aim of this study was to evaluate the effects of remnant root canal medicament, calcium hydroxide on the short and long term sealing ability of mineral trioxide aggregate [MTA] apical barrier. Fifty single-rooted teeth were prepared and apical resorptions were made using sulfuric acid. The teeth were allocated into two experimental groups and two control groups. In group 1, calcium hydroxide was placed into canals for one week. In group 2, no medication was placed. In both groups, a 4-mm MTA plug was placed in the root canals. The remaining portion of the canal was filled with gutta-percha/sealer. The microleakage was evaluated after 7 days and 3 months using fluid filtration technique. Repeated measurement ANOVA was used for statistical analysis. There was no significant difference in sealing ability between the two groups in either time periods. In both groups, microleakage decreased after three months but this decrease was not statistically significant. Medication with calcium hydroxide had no adverse effect on the short and long-term sealing properties of MTA plug