Detection of efflux pump genes in multiresistant Acinetobacter baumannii ST2 in Iran.

Acinetobacter baumannii, as a nosocomial pathogen has become a worldwide concern in recent years. In the current study, the resistance to tetracyclines and colistin were assessed in the isolates from different provinces of Iran.During the timeline of this study, a number of 270 isolates of A. baumannii were collected from tracheal aspirates, wounds, urine and blood cultures. The minimum inhibitory concentration (MIC) for tetracycline, doxycycline, minocycline, tigecycline and colistin were evaluated. Tetracycline resistance genes were assessed by PCR. The mean expression level of adeB, adeJ and adeG were assessed using semi quantitative Real-Time PCR. The clonal relationship of the isolates was evaluated by the repetitive extragenic palindromic PCR (REP-PCR), International Clonal (IC) Lineage Multiplex PCR and multilocus sequence typing (MLST) (Pasteur scheme) methods.The MIC by microdilution method showed that 87.5, 51.4, 28, 0.74 and 0% of the isolates were resistant to tetracycline, doxycycline, minocycline, tigecycline and colistin respectively. The prevalence of tetracycline resistance genes was 99.2, 99.2, 98, 86.7, 10, 3.33, 0.37, 0% for adeB, adeJ, adeG, tetB, tetA(39), tetA, tetM and tetH in tetracycline-resistant isolates. Moreover, the expression level of adeB, adeJ, adeG genes in tigecycline-nonsusceptible A. baumannii (TNAB) strain was higher compared to the tigecycline-susceptible A. baumannii (TSAB). A broad genomic diversity was revealed, but ST2 was the most prevalent ST. Our results indicated that tetracycline resistance in Iran is mediated by resistance-nodulation-cell division (RND) and tetB efflux pumps.

The Comparison of Different Irrigation Systems to Remove Calcium Hydroxide from the Root Canal: A Systematic Review and Meta-Analysis

Abstract Objective: To examine the effect of a variety of irrigation systems on the removal of root canal Ca (OH)2 residues through meta-analysis and systematic review. Material and Methods: A search of relevant articles was systematically performed on databases of Medline, PubMed, Cochrane Library, Embase, ISI, and Google Scholar published from 2013 to 2019. Electronic title management was carried out by EndNote X9 software. Searches were based on the main keywords of "Irrigation Systems", "Calcium Hydroxide"," Root Canal", "Self-adjusting File OR SAF", "Conventional Irrigation", "EndoVac System", "Ultrasonic Irrigation" and "YAG Laser". Results: The studies investigated were found to lack any standardization concerning the irrigation method used or the measurement of outcomes; for instance, different studies used 5 or 10 mL of 2.5% NaOCl, or 5 mL of 5.25% NaOCl, or 0.5 mL, 3 mL and 10 mL of 17% EDTA. Conclusion: The effective techniques for the removal of root canal Ca(OH)2 were PUI, and SAF approaches.

Efficacy of Lasers Treatment of Exposed Pulps to Stimulate Healing: A Systematic Review and Meta-Analysis

Abstract Objective: The present systematic review and meta-analysis aimed at evaluating the efficacy of laser's treatment of exposed pulps to stimulate healing. Material and Methods: MEDLINE, PubMed, Cochrane Library, Embase, ISI, Google Scholar have been searched as the electronic databases for performing systematic literature between 2005 to 2019. Searches were performed with MESH terms. The quality of the studies included was assessed using the Critical Appraisal Skills Program checklist. For Data extraction, two reviewers blind and independently extracted data from the abstract and full text of the studies included. Moreover, the fixed-effect model's odds ratio for a 95% confidence interval (CI) was calculated. Random effects were used to deal with potential heterogeneity, and I2 showed heterogeneity. The meta-analysis and forest plots have been evaluated using the Comprehensive Meta-Analysis Stata. Results: Five studies (3 RCTs and 2 animal studies) were included in this study. The Odds Ratio was 1.90 (95% CI 1.39-2.42; p=0.00); there was a statistically significant difference between the laser and the control groups (p=0.00). Conclusion: The success rate of laser treatment for exposed pulps is higher than mineral trioxide aggregate, resin, calcium hydroxide and resin-modified glass-ionomer cement. The exact mechanism of this effect has not yet been determined; further research on lasers' impact on exposed pulps treatment is required.

Comparison of the effect of root canal preparation by using WaveOne and ProTaper on postoperative pain: a randomized clinical trial.

INTRODUCTION: WaveOne is a single-file reciprocating instrumentation system with the benefits of M-Wire alloy that has increased flexibility and improved resistance to cyclic fatigue over the conventional alloy. Root canal preparation techniques may cause postoperative pain. The goal of the present study was to compare the intensity and duration of postoperative pain when using WaveOne or ProTaper Universal systems for instrumentation of root canals. METHODS: Forty-two patients who fulfilled specific inclusion criteria were assigned to 2 groups according to the root canal instrumentation technique used, WaveOne or ProTaper Universal. Root canal treatment was carried out in 2 appointments, and the severity of postoperative pain was assessed by numerical rating scale (NRS) score after each session until complete pain relief was achieved. Analgesic consumption, duration of pain, and root canal preparation time were also recorded. RESULTS: The mean NRS score and duration of pain after both appointments were significantly higher in the WaveOne group (P < .05); however, the mean analgesic consumption was only significantly higher in the WaveOne group after the first appointment (P < .05). In all groups the highest mean NRS score was seen 6 hours after each therapeutic appointment. Canal preparation time was significantly shorter in the WaveOne group (P < .001). CONCLUSIONS: Postoperative pain was significantly lower in patients undergoing canal instrumentation with ProTaper Universal rotary instruments compared with the WaveOne reciprocating single-file technique.