Molecular Identification of Candida albicans in Endodontic Retreatment Cases by SYBR Green I Real-time Polymerase Chain Reaction and its Association with Endodontic Symptoms.

Statement of the Problem: Recent microbiological studies have expressed ever-increasing concerns about Candida albicans as a causal factor in the failure of endodontic treatments. Real-time quantitative polymerase chain reaction (qPCR), including the SYBR Green I system, is a technique in which a fluorescent dye is incorporated into the double-stranded DNA that is produced during DNA polymerase activity. Purpose: This study aimed to determine the relative prevalence of Candida albicans in root canals of retreatment cases and its association with endodontic symptoms. Materials and Method: In the present cross-sectional/analytical study fifty subjects were selected. Clinical features and radiographic status of the teeth were also evaluated. After access cavity preparation, the retrieved material and dentinal chips removed from the root canal were transferred into 1.5-mL microtubes, followed by storage at -20ºC until used for DNA extraction. A DNeasy Tissue Kit was used to extract DNA using the DNeasy protocol for animal tissues. Master Plus SYBR Green I (Jena Bioscience, Germany) was used in a Rotor-gene Real-time PCR System for real-time PCR. The relationship between the presence of Candida albicans and the clinical and radiographic features were analyzed using McNemar's test. Results: There was a significant relationship between the radiographic findings in endodontically treated teeth and the presence of Candida albicans. However, there was no significant relationship between the presence of Candida albicans and any of the clinical symptoms. Conclusion: In spite of the limitations of this study, we concluded that Candida albicans was associated with root canal infections in endodontic retreatment cases, but there was no relationship between root canal infections and the clinical symptoms.

Revealing seed color variation and their possible association with yield and quality traits in a diversity panel of flax (Linum Usitatissimum L.).

Seed color is a vital quality determinant of flax, significant for consumers' acceptability, and determines the commercial values of seeds. Also, seed color as a phenotypic marker may be a convenient way to select the plants with desired traits. This study assessed a diversity panel representing 144 flax genotypes from diverse geographical origins for the existence of genetic variability for luminosity (L*) and chromaticity (a* and b*) seed color parameters, seed yield, and quality traits over two years. The genetic variance was significant for seed color parameters, demonstrating the presence of significant genetic variability, which provides a resource to objectively evaluate and select flax genotypes based on seed color according to the market demand. High heritability combined with the high genotypic coefficient of variation observed for seed yield, oil, and protein content suggested a better genetic gain upon selecting these traits. Seed yield, seed quality traits, and phenological traits showed significant negative correlation with L* and b* parameters and positive correlation with a* suggesting that the seeds' dark background and brown color can serve as marker characters to prescreen early-flowering, high-yielding and oil and protein-rich genotypes. Interestingly 48 brown-seeded genotypes were identified as early-flowering with short height, large seeds, high thousand seed weight, and capsule diameter. In addition, 34 genotypes were characterized by light-colored yellow seeds, large seeds, late-flowering with shorter height, and high branch numbers. Our results highlighted that North America and Australia-belonged genotypes were lighter yellow-seeded than the ones from other continents. Flax genotypes from South America and Asia were high-yielding, while genotypes from North America were low-yielding genotypes. Moreover, darker brown-seeded genotypes have prevailed in the South American continent.

Abdominal aortic aneurysm screening during transthoracic echocardiography in asymptomatic patients in Guilan province.

Background: The prevalence of detected abdominal aortic aneurysm (AAA) during transthoracic echocardiography (TTE) has been different in previous studies based on the study population, and no data are available on AAA in the population of north of Iran. The aim of this study was to investigate the prevalence of AAA in individuals aged 50 and over in the north of Iran who were a candidate for TTE. Methods: This cross sectional study was conducted on all individuals aged 50 and over who referred to our cardiovascular center for TTE evaluation from October 2016 to October 2017. The maximum diameter of the whole abdominal aorta was accepted as abdominal aortic size and a diameter ≥ 30 mm as AAA. All statistical analyses were conducted using SPSS Version 22.0. Also, Mann-Whitney and chi-squared tests were used to compare variables. A p<0.05 was considered significant. Results: In total, 1411 patients underwent TTE in this study and abdominal aorta was visualized in 1329 patients (93.9%) successfully. The prevalence of AAA was 0.5% (7 patients, 95% CI: 0.496-0.503) during the study period. Patients with AAA were significantly older (p=0.002), with a mean age of 74.4±7.7 years, and 85.7% (6 patients) had hypertension, which was significantly higher (p=0.022) than patients without AAA. Conclusion: This study showed that the AAA prevalence during standard TTE in the northern population of Iran aged 50 and over was 0.5%, which was lower than a previous study in Tehran that found AAA on 3.8% of screened patients. Patients with AAA in this population were significantly older and more hypertensive.

Comparison of Flexural Strength of Mineral Trioxide Aggregate, Calcium-enriched Mixture and BioAggregate.

Introduction: The aim of this study was to compare the flexural strength of mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM), and BioAggregate (BA). Methods and Materials: In this study, the flexural strength of materials was measured using a 3-point bend test. After being prepared, MTA, CEM, and BA were inserted into the intra-putty molds using amalgam plugger. The specimens were covered with a sponge wetted with synthetic tissue fluid (STF) and incubated for 96 h. They were then subjected to a 3-point bend test using Universal Testing Machine. The Kruskal-Wallis and Mann-Whitney U tests were used to compare flexural strength in groups. In this study, P<0.05 was considered as the significant level. Results: There were significant differences between the three groups in terms of the flexural strength (P<0.001). The mean flexural strength in the BA, CEM, and MTA groups were 27.32±2, 9.09±1.16, and 10.25±1.6, respectively. Pairwise comparison showed significant differences between the three groups. Conclusion: This in vitro study showed that BA has the highest and CEM has the lowest flexural strength.

Effect of Duration of Irrigation with Sodium Hypochlorite in Clinical Protocol of MTAD on Removal of Smear Layer and Creating Dentinal Erosion.

BACKGROUND AND AIMS: The aim of the present study was to compare 1.3% sodium hypochlorite (NaOCl) in MTAD (mixture of tetracycline isomer, acid, and detergent) for the removal of the smear layer and induction of canal erosion. MATERIALS AND METHODS: 38 maxillary incisors were divided in three experimental groups of 10 and two positive and negative control groups of each 4 teeth, and prepared using rotary files. In test groups, 1.3% NaOCl was used for 5, 10 and 20 minutes during preparation followed by MTAD as the final rinse. In negative control group, 5.25% NaOCl was used for 10 minutes followed by 17% Ethylenediamine Tetra-Acetic Acid (EDTA) as the final rinse. In positive control group, dis-tilled water was used for 10 minutes during preparation and then as the final rinse. The samples were examined under scan-ning electron microscope, and the smear layer and dentinal erosion scores were recorded. RESULTS: Five and 10 min groups had significant differences with 20 min group (p < 0.05). In apical third, 5 and 10 min groups had also significant differences with 20 min (p < 0.05). In the coronal thirds, when the time of irrigation with 1.3% NaOCl increased from 5 min to 20 min, erosion also increased significantly. However, 5 and 10 min groups had no signifi-cant differences with negative control group. CONCLUSION: The use of 1.3% sodium hypochlorite for 5 and 10 minutes in the MTAD protocol removes the smear layer in the coronal and middle thirds but does not induce erosion.