Effect of smear clear and some other commonly used irrigants on dislodgement resistance of mineral trioxide aggregate to root dentin

This study aimed to assess the push-out bond strength of mineral trioxide aggregate (MTA) to root canal dentin after irrigation with Smear Clear in comparison with 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) and saline as commonly used root canal irrigants. The coronal and mid-root areas of maxillary anterior teeth were horizontally sectioned into one-millimeter thick slices. The root canal lumen of dentinal slices was dilated using a diamond bur with 1.3 mm diameter. After the application of MTA, the samples were incubated in 100% humidity for 10 minutes and were then randomly divided into four groups (n=20) and immersed in Smear Clear, 2.5% NaOCl, 2% CHX and saline for 30 minutes. No irrigant was used for the control group (n=20). A wet cotton pellet was placed on the samples and after 48 hours of incubation, push-out bond strength was measured using a universal testing machine. The samples were evaluated under a stereomicroscope to determine the mode of failure. One-way ANOVA was used to assess statistical differences among the groups. The control group showed the highest bond strength with significant differences with other groups (P0.05). Other pairwise comparisons showed no significant difference (P>0.05). Irrigation with Smear Clear, CHX and NaOCl did not cause a significant change in bond strength of MTA to dentin

Effect of Smear Clear and Conventional Root Canal Irrigants on Push-Out Bond Strength of Resilon/Epiphany System

Introduction: The aim of the present study is to compare the effect of SmearClear and sodiumhypochlorite (NaOCl), chlorhexidine (CHX) and normal saline (NS) on the push-out bond strength of Resilon/Epiphany system to dentine. Methods and Materials: In this in vitro study; 48 single-rooted teeth were selected and decoronated from the CEJ. Then the specimens were divided into four groups (n=12). The roots were prepared by single length technique using MTwo rotary system. The final irrigations of the canals were done using 2% CHX, normal saline, 5.25% NaOCl or SmearClear. The canals were obturated by Resilon/Epiphany system. The teeth were cut perpendicular to their longitudinal axis and four 1-mm-thick sections were obtained from coronal and mid root regions. The push-out bond strength of Resilon/Epiphany system to dentin were calculated and bond failure patterns were assessed. The data were subjected to two-way analysis of variance and Tukey’s tests. Results: The highest bond strength values were reported for SmearClear and the lowest values for the NS solutions. The effects of irrigant type (P<0.05) and canal area (P<0.0001) on the bond strength of Resilon to dentin were significant (P<0.05). Higher bond strength values were obtained in the mid root areas compared to the coronal regions. In two-by-two comparisons, significant differences in bond strength were found between SmearClear and normal saline (P<0.05) while the other irrigants showed no significant differences (P>0.05). Conclusion: SmearClear solution was able to increase the push-out bond strength of Resilon to the dentin similar to other irrigants (NaOCl and CHX). Therefore, it can be used for the root canal irrigation and smear layer removal in the clinical situations.Keywords: Push-But Bond Strength; Resilon; Root Canal Irrigation; SmearClear; Smear Laye

Chronic myeloid leukemia as a stem cell-derived malignancy

Chronic myeloid leukemia (CML) is a myeloproliferative disease of the hematopoietic stem cells, characterized by the presence of the Philadelphia (Ph) chromosome. Although imatinib inhibits the BCR-ABL kinase activity, clinical experiences confirm that imatinib may not target CML stem cells in vivo. The identification of signaling pathways responsible for the self-renewal properties of leukemic stem cells in CML will help in the discovery of novel therapeutic targets. Here we review signaling pathways including Wnt/β-catenin, Hedgehog, Alox5, and Foxo which play crucial roles in the maintenance of stem cell functions in CML. It is thought that inhibition of key genes that are part of self-renewal associated signaling pathways may provide an effective way to reduce aberrant stem cell renewal in CML

Comparison of Apical Transportation with the Use of Rotary System and Reciprocating Handpiece with Precurved Hand Files: An In Vitro Study

Introduction: Success of root canal treatment depends on several factors; among which, maintaining the original canal path during mechanical preparation is extremely important. This in vitro study aimed to compare apical transportation using RaCe NiTi rotary system and precurved stainless steel (SS) hand files in a reciprocating handpiece. Methods and Materials: Mesiobuccal canals of 40 extracted human mandibular first and second molars with 20 to 45° curvatures and 3 to 7 mm curve radius were chosen for this study. After working length determination, the teeth were divided into two groups (n=20). Root canals were prepared with RaCe in group 1 and NSK handpiece and precurved SS hand files in group 2 up to #30 with 2% taper in both groups. Radiographs were taken of teeth before and after instrumentation from buccolingual and mesiodistal directions. The images were superimposed using Adobe Photoshop CS3 software. Degree of straightening and amount of apical transportation at 0, 0.5, 1, 2, 3, 4 and 5 mm levels short of the working length were determined using digital subtraction radiography. The student’s t test was used to compare the degree of straightening and Mann Whitney test was applied to compare apical transportation (millimeters) between the two groups. Results: No significant difference was noted between the two groups on buccolingual or mesiodistal views in degree of straightening and apical transportation on buccolingual view (P>0.05). However, on mesiodistal view, NSK reciprocating handpiece caused greater apical transportation at 0. 0.5 and 1 mm levels (P<0.05). Conclusion: The RaCe system and precurved SS files in reciprocating handpiece were highly similar in terms of degree of straightening and apical transportation. Thus, engine-driven NSK reciprocating handpiece can be used as an efficient adjunct for root canal preparation.Keywords: Canal Transportation; RaCe Instruments; Reciprocating Handpiec

What is the best laboratory method for diagnosis of Herpes Simplex Virus in genital infections?

  Genital infection caused by Herpes simplex virus (HSV) is one of the most common health problems, worldwide. Several methods such as cell culture, serological and molecular methods have been used to detect this virus. Currently, Real-Time Polymerase Chain Reaction (Real time-PCR) technique is widely used due to its high sensitivity and specificity. Besides, Real time-PCR can be employed in the follow-up of therapeutic effects in HSV-infected person who is being treated with antiretroviral drugs. We conducted a review on traditional and current diagnostic methods with a focus on their limitations in the diagnosis of HSV infection

Clinical characteristics and outcomes of COVID-19 patients with a history of cardiovascular disease

New emerging severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) primarily affects the lungs, but the virus may cause cardiovascular disease (CVD), and a history of CVD is usually associated with comorbidities, which could increase the severity of infections. In this study, we collected demographic and clinical characteristics data from 123 patients with a history of CVD, who were confirmed to have SARS-CoV-2 infection by polymerase chain reaction (PCR) test in Razi Hospital, Rasht, Iran, from March 2021 to June 2021. Chi-Square and Fisher's Exact test with a significance level of P less than 0.05 was performed. All statistical analysis was performed with SPSS software version 26.0. Among the studied patients, 99 patients were discharged and 24 of them died. 62 (50.4%) of the study population were female and 61 (49.6%) were male, and there is no significant association between gender and the outcome of patients (P = 0.159). The total mean age of patients was 68.35±12.41. Statistical analysis has represented a significant relation of death outcomes in CVD patients with age 60 years and older (P = 0.001), in comparison with patients younger than 60 years. In this present study, no significant relation between underlying disease and mortality rate was reported, but in COVID-19 patients with a history of CVD and age upper than 60 years, death outcome was more probable

A genetic variant in CDKN2A/2B locus was associated with poor prognosis in patients with 1 esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is among the leading causes of cancer related death. Despite extensive efforts in identifying valid cancer prognostic biomarkers, only a very small number of markers have been identified. Several genetic variants in the 9p21 region have been identified that are associated with the risk of multiple cancers. Here, we explored the association of two genetic variants in the 9p21 region, CDKN2A/B, rs10811661 and rs1333049 for the first time in 273 subjects with, or without ESCC. We observed that patients with ESCC had a higher frequency of a TT genotype for rs10811661 than individuals in the control group, and this polymorphism was also associated with tumor size. Moreover, a CC genotype for the rs1333049 polymorphism was associated with a reduced OS of patients with ESCC. In particular, patients with a CC (rs1333049) genotype had a significantly shorter OS (CC genotype: 34.5±8.9 months vs. CG+GG: 47.7±5.9 months; p value= 0.03). We have also shown the association of a novel genetic variant in CDKN2B gene with clinical outcome of ESCC patients. Further investigations are warranted in a larger population to explore the value of emerging markers as a risk stratification marker in ESCC. Key word: Esophageal squamous cell carcinoma, risk marker, CDKN2A/B, polymorphis