Recent advances in pre-conditioned mesenchymal stem/stromal cell (MSCs) therapy in organ failure; a comprehensive review of preclinical studies.

Mesenchymal stem/stromal cells (MSCs)-based therapy brings the reassuring capability to regenerative medicine through their self-renewal and multilineage potency. Also, they secret a diversity of mediators, which are complicated in moderation of deregulated immune responses, and yielding angiogenesis in vivo. Nonetheless, MSCs may lose biological performance after procurement and prolonged expansion in vitro. Also, following transplantation and migration to target tissue, they encounter a harsh milieu accompanied by death signals because of the lack of proper tensegrity structure between the cells and matrix. Accordingly, pre-conditioning of MSCs is strongly suggested to upgrade their performances in vivo, leading to more favored transplantation efficacy in regenerative medicine. Indeed, MSCs ex vivo pre-conditioning by hypoxia, inflammatory stimulus, or other factors/conditions may stimulate their survival, proliferation, migration, exosome secretion, and pro-angiogenic and anti-inflammatory characteristics in vivo. In this review, we deliver an overview of the pre-conditioning methods that are considered a strategy for improving the therapeutic efficacy of MSCs in organ failures, in particular, renal, heart, lung, and liver.

Comparing knowledge and opinions of medical and dental students in the field of pediatric anesthesia.

Background and Purpose: Dental treatment under general anesthesia (GA) is one of the common treatment methods today for dental treatment in children, so dentists' point of view in this field is very important. Therefore, the purpose of this study was evaluation the awareness and attitude of pediatric dentists and final-year dental students about dental treatment for children under GA. Methods: To conduct this study, 150 people, including 75 general dentists (GD) and 75 final-year dental students (FYDS), were randomly selected in Tehran. In this study, a researcher-made questionnaire containing 15 questions (7 awareness questions and 8 attitude questions) was used to evaluate the awareness and attitude of the participants. After extracting the raw results, statistical analysis of the results was done using SPSS-Ver. 22 software. Results: 60% of the participants (90 people) were men and the remaining 40% (60 people) were women. The results showed that the level of awareness of male dentists was significantly higher than that of female dentists (P = 0.015). In addition, although the awareness level of FYDS was lower than GD, this difference was not statistically significant (P = 0.130). The average level of awareness among different age groups had a significant difference (P = 0.009), so the age group of 36-45 years compared to the younger age groups (25-35 years) and the older age groups (36-45 and 55 -46 years), had a higher level of awareness. Conclusion: According to the findings, it can be concluded that it is necessary to use appropriate educational methods to improve the level of awareness and attitude of children's dentists.

Exosomes derived from mesenchymal stem cells: Heralding a new treatment for periodontitis?

Periodontitis, as a complex inflammatory disorder, is characterized by continuous destruction of the teeth-supporting components, like alveolar bone and periodontal ligament, and affects a great percentage of individuals over the world. Also, this oral disease is linked with multiple serious illnesses, e.g., cardiovascular disorders, diabetes, and oral cancer; thus, exerting efficient therapy for periodontitis is necessary. Unfortunately, the current therapies for the disease (e.g., surgical and nonsurgical methods) have not reflected enough effectiveness against periodontitis. At present, mesenchymal stem cell (MSC)-based remedy has created new hope for curating different diseases; however, MSCs have no capability to engraft into the chosen tissue, and the tumorigenic influences of MSCs are still the main concern. Interestingly, documents have revealed that MSC-derived mediators, like exosomes, which their exploitation is more feasible than intact MSCs, can be an effective therapeutic candidate for periodontitis. Therefore, in this study, we will review evidence in conjunction with their possible curative impacts on periodontitis cases.

SARS-CoV-2-associated gut microbiome alteration; A new contributor to colorectal cancer pathogenesis.

The emergence of a novel coronavirus, COVID-19, in December 2019 led to a global pandemic with more than 170 million confirmed infections and more than 6 million deaths (by July 2022). Studies have shown that infection with SARS-CoV-2 in cancer patients has a higher mortality rate than in people without cancer. Here, we have reviewed the evidence showing that gut microbiota plays an important role in health and is linked to colorectal cancer development. Studies have shown that SARS-CoV-2 infection leads to a change in gut microbiota, which modify intestinal inflammation and barrier permeability and affects tumor-suppressor or oncogene genes, proposing SARS-CoV-2 as a potential contributor to CRC pathogenesis.

Biosynthesis of Zn-doped CuFe2O4 nanoparticles and their cytotoxic activity.

Zn-doped CuFe2O4 nanoparticles (NPs) were eco-friendly synthesized using plant extract. These nanoparticles were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy and thermal gravimetric analysis (TGA). SEM image showed spherical NPs with size range less than 30 nm. In the EDS diagram, the elements of zinc, copper, iron, and oxygen are shown. The cytotoxicity and anticancer properties of Zn-doped CuFe2O4 NPs were evaluated on macrophage normal cells and A549 lung cancer cells. The cytotoxic effects of Zn-doped CuFe2O4 and CuFe2O4 NPs on A549 cancer cell lines were analyzed. The Zn-doped CuFe2O4 and CuFe2O4 NPs demonstrated IC50 values 95.8 and 278.4 µg/mL on A549 cancer cell, respectively. Additionally, Zn-doped CuFe2O4 and CuFe2O4 NPs had IC80 values of 8.31 and 16.1 µg/mL on A549 cancer cell, respectively. Notably, doping Zn on CuFe2O4 NPs displayed better cytotoxic effects on A549 cancer cells compared with the CuFe2O4 NPs alone. Also spinel nanocrystals of Zn-doped CuFe2O4 (~ 13 nm) had a minimum toxicity (CC50 = 136.6 µg/mL) on macrophages J774 Cell Line.

Effects of Diode Low-Level Laser Therapy of 810 Nm on Pulpal Anesthesia of Maxillary Premolars: A Double-Blind Randomized Clinical Trial.

OBJECTIVE: The purpose of this study was to investigate the pulpal effect of diode low-level laser therapy (LLLT) of 810 nm on the alleviation of pain in patients requiring dental procedures. METHODS: The current study was a double-blind randomized clinical trial carried out on twenty participants. The electric pulp testing (EPT) was recorded at baseline. Patients were randomly divided into sham laser and laser group respectively receiving low-level laser with placebo and active probes. Low-level laser at 810 nm, 200 MW constant power, 30s irradiation time and energy dose of 6 J was used. The electric pulp testing (EPT) method was again adopted to assess the rate of induced anesthesia. Laser and sham laser treatments were carried out in two different sessions with a one-week interval to ensure avoiding the potential false placebo results. Data were analyzed in SSPS-24 using Chi-square test and t-test. The p-value was set at 0.05. RESULTS: A low-level laser at 810 nm significantly alleviate EPT-induced pain compared to the pain before laser irradiation (P≤0.001). While the difference of EPT-induced pain before and after sham laser irradiation was not significant in control group (P>0.05). There was no correlation between the anesthetic effects of a laser application at 810 nm and other variables including age and gender (P>0.05). CONCLUSION: An 810 nm low-level laser is a powerful device for induced anesthesia applications in patients requiring dental procedures. It also lessens the patients' fear of dental procedures.

Determine the Dentists' Practice in Compliance with General and Guidelines for Handling Coronavirus Disease 2019: A Systematic Review and Meta-analysis

ABSTRACT Objective: To determine the Dentists' practice in compliance with general and guidelines for handling Coronavirus Disease 2019. Material and Methods: PubMed, Embase, ISI, Scopus, Medicine have been used to search for articles until September 2020. EndNote X9 was used to manage electronic resources as a resource. Joanna Briggs Institute reviewer's manual (JBI) tools was used to assess the quality of studies included in the current systematic and meta-analysis review. The 95% confidence interval (CI) effect size, the random effect model, and the Restricted maximum-likelihood (REML) methods have all been calculated. I2 values of more than 50% indicated moderate-to-high heterogeneity. Stata/MP v.16 (the fastest version of Stata) statistical software was used to evaluate the Meta-analysis. Results: 39 articles were found in the initial keyword search. The full text of 16 studies was reviewed, and six studies were selected in the end. 72% of participants used a face mask during the dental procedure (72%, 95% CI; 40%-100%). 63% of participants measured fever when patients arrived during the COVID-19 pandemic (63%, 95% CI; 46%-79%). Moreover, 72% of participants used a face mask during the dental procedure (72%, 95% CI; 40%-100%). According to JBI tools, all studies had a moderate risk of bias. Conclusion: The results show that the performance of dental professionals in the conditions of the COVID-19 epidemic is not favorable. Training should be under the standards of treatment guidelines and further measures so that dental professionals can show proper practice by increasing their awareness of this virus and following up on its infection.

Comparison of Microscopic Endodontic Techniques: A Systematic Review and Meta-Analysis

ABSTRACT Objective: To evaluate the success rates of resin-based endodontic surgery (RES) and endodontic microsurgery (EMS), and compare their results. Material and Methods: A total of 19 and 34 full-text papers were reviewed, and finally, 2 and 6 studies were selected for RES and EMS, respectively. The stages of the study selection process were illustrated in Figure 1. The demographic characteristics were also described using the IBM SPSS Software, and the meta-analysis was fulfilled via Stata V.14. Results: A total number of 811 teeth were analyzed in this systematic review and meta-analysis, with a mean follow-up of 38.63 months. Besides, the results of the meta-analysis indicated that both methods not only differed in terms of implementation but also produced varying outcomes. Accordingly, EMS demonstrated a higher success rate likelihood with a significant difference from that of RES. Conclusion: An excellent proof was made available through this meta-analysis regarding the resin-based endodontic surgery success rate likelihood (79.9%) and an update for the endodontic microsurgery success rate possibility (100%).

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.

Dental Pulpal Tissue Regeneration, Pulpal Vitality Testing, and Healing of Apical Lesions Following Stem Cell Transplant: A Systematic Review and Meta-Analysis

Abstract Objective: To analyze data obtained from animal and human studies using stem cells. Material and Methods: Medical Literature Analysis and Retrieval System Online (MEDLINE), PubMed, Cochrane Library, Embase, Information Sciences Institute (ISI), as well as Google Scholar were utilized and searched as available electronic databases to perform a systematic literature review of articles published between 2010 and 2019. The Endnote X9 for Windows was also employed to manage electronic titles and abstracts of the selected studies. Searches were conducted using keywords of "pulpal OR pulpal tissue OR pulpal vitality", "regeneration", "apical healing", "stem cells OR progenitor cells", and "mediated pulpal tissue". Consequently, 189 titles and abstracts endowed with potential relevance were discovered based on searches into manual and electronic sources. Ultimately, a total of six articles met the inclusion criteria in the present systematic review and meta-analysis. Results: Out of the six articles identified and selected, five studies were categorized as animal experiments and one article was nominated as a human clinical trial. The greatest bias risks were accordingly observed in the majority of animal examinations, but articles related to humans revealed decreased risks of bias, while the human clinical trial showed some concerns. Conclusion: Promising parameters testing functional pulp regeneration could be represented through stem cell transplants.

Evaluation of the relationship between crown size and root canal morphology of mandibular incisors by cone beam computed tomography (CBCT).

BACKGROUND: The main reason for the failure of endodontic therapy is the incomplete knowledge about the anatomical variation of root canals. One of the most important factors that leads to the failure of root canal treatment, is missed and untreated major root canals. OBJECTIVE: with respect to the complexity of mandibular incisors treatment and high prevalence of the second canal, and the possibility of the relationship between the crown size and the extra canal in these teeth, the aim of this study was to determine the relationship between crown size and root canal morphology in mandibular incisors with CBCT. METHODS: In this cross-sectional study, mandibular permanent incisors were randomly collected in Qazvin City, Iran, and were mounted in eight ternary groups on a plastic slot, using putty molding material. After preparation of Scot view, the samples were scanned by CBCT NewTom 5G. Afterward, the mesiodistal and buccolingual dimensions were measured by the software's measurement tool with a precision within tenths of a millimeter. In the next stage, a multi-planar option and 400% magnification tool of the software were utilized to study axial and cross sectional views of each tooth to determine canal type. Data were analyzed employing one-sample Kolmogorov-Smirnov, Levene, independent- samples t-test and Roc curve by SPSS version 20. RESULTS: The majority of mandibular incisors have a single canal (63.9% of them had type I canal system). In addition, 36.1% of the roots had two canals, among which, type III was the most common. The mean of maximum mesiodistal and buccolingual diameters in type III was significantly bigger than that in type I (p<0.05), but the means of crown size in the two canal types were not significantly different. CONCLUSION: Despite increase in mesiodistal and buccolingual dimension in two canal mandibular incisors with type III canal system, their crown sizes (M-D/F-L index) were not significantly different, in comparison to single canal incisors.

Evaluation of the effect of tooth type and canal configuration on crown size in mandibular premolars by cone-beam computed tomography.

INTRODUCTION: To achieve success in treatment, one cannot ignore the knowledge of pulp anatomy. Mandibular premolars are considered to be the most difficult teeth for endodontic therapy due to high variability in their canal morphology. It is possible that a relation exists between the crown size and the number of extra canals in these teeth, so this in vitro study aims to investigate the relationship between the crown size and the uncommon morphology of mandibular premolars using Cone-Beam Computed Tomography (CBCT). MATERIALS AND METHODS: Eighty three extracted mandibular human premolars were exposed to radiation using the CBCT device. Root canal configuration was categorized according to the Vertucci's classification. The crown size was measured in three axial, coronal and sagittal sections. Finally, the relation between these two factors was evaluated with variance analysis (two-way ANOVA) and chi-square. RESULTS: The most common canal type in the mandibular first and second premolars are type I (71% and 76%, respectively), followed by type V (29% and 22%, respectively). No significant relationship was found between the crown size and extra canals in mandibular premolars (P>0.05). CONCLUSION: In this in vitro study, the average crown size in two-canalled second premolars was less than that in first premolars with a single canal; although the difference was not statistically significant. The research hypothesis was therefore rejected in both first and second mandibular premolars.

Fracture strength of mesiobuccal roots following canal preparation with hand and rotary instrumentation: an in vitro study.

INTRODUCTION: The aim of this in vitro study was to compare the effect of hand and rotary instruments on fracture strength of tooth roots. MATERIALS AND METHODS: Thirty two teeth were randomly divided into two experimental groups of 15 each and one negative control group with two samples. In group 1, step-back technique with conventional stainless steel K-files was used, and in group 2, instrumentation was performed using rotary Ni-Ti Hero642. Samples in control group did not receive cleaning or shaping after access cavity preparation. After obturating each canal, tip of the spreader was locked within canal. The required force for root fracture was measured using Instron testing machine. Recorded data was statistically analyzed using t-test. RESULTS: The mean and standard deviation force required for vertical root fracture were 50.33±19.1 and 63.1±25.46 N for hand and rotary groups respectively. However, no significant difference was found between experimental groups. CONCLUSION: The results indicate that the manual technique did not lower fracture strength of obturated roots in comparison with the rotary preparation technique.