anahita lotfizadeh

Regenerative treatments in endodontics are biological treatments to manage immature teeth, remove inflamed and necrotic tissue, and create a suitable environment for tissue repair. In these treatments, substances with reparative properties of dental pulp and dentin are placed on the pulpal tissue. Interleukin-6 is one of the cytokines secreted in response to various immune activities of the body and studies have demonstrated its vital role in mineralization induction and hard tissue formation. Recently, calcium silicate-based materials have been widely implemented in dentistry due to their great biocompatibility and hard tissue formation induction. Considering the role of IL-6 in the regulation of stem cells, the purpose of this study is to compare the effect of CEM cement, Biodentine, TheraCal LC, and MTA on the level of IL-6 secretion by dental pulp stem cells.

In this laboratory study, 4 types of cement were used as the main groups, and 1 control group contained culture medium without cement. Discs were prepared under sterile conditions in six-well plates with a diameter of 35 mm and a height of 2 mm and they were given time to set for 48 hours. Human pulp stem cells were obtained from Iran's Center for Biological Resources and cultured in a culture medium containing DMEM with 15% FBS and 1% penicillin-streptomycin (10,000 units/ml) as antibiotics. Pulp stem cells at passages 3-5 were used for experiments. Discs of each cement were prepared under sterile conditions and according to the manufacturer's instructions. To prepare the extract of each cement, the DMEM cell culture medium was placed near these discs for 24 hours. Then, human dental pulp stem cells (hDPSCs) were cultured in the vicinity of the disc extract for 72 hours. After that, this extract was collected and the level of IL-6 secretion in it was measured by the ELISA method. The experiments were repeated 3 times. Then the obtained data were entered into SPSS 16 software and analyzed using analysis of variance and the Kruskal-Wallis test.

The results showed that the highest level of IL-6 secretion by cells was in the presence of TheraCal LC, Biodentine, and CEM, respectively; But there was no significant difference between the groups. The average level of IL-6 secretion in the presence of MTA was lower than in other groups and this difference was significant (P<0.01).

The results of the present study showed a lower level of IL-6 cytokine secretion by pulpal stem cells in the presence of MTA compared to TheraCal, CEM, and Biodentine types of cement. Considering the role that IL-6 can have in osteogenic and odontogenic activities, the results of this study can be useful in establishing information in the field of introducing the most suitable cements for clinical procedures.

Successful root canal treatment depends on correct cleaning, widening, and shaping of the root canal system. Root canal preparation using rotary files can cause dentin cracks. This study aimed to evaluate the number of dentin cracks created after the preparation of the mesiobuccal root canal of the first maxillary molars by ProTaper Gold and Edge taper platinum rotary files using a stereomicroscope.

In this laboratory study, 72 maxillary first molars were collected and randomly divided into three groups (n=24): control group, ProTaper Gold group, and Edge taper platinum group. Mesiobuccal canal preparation was performed in Edge taper platinum and ProTaper Gold groups up to file size F2. All roots were cut horizontally at distances of 3, 6, and 9 mm from the apex with a disc. The sections were examined under a stereomicroscope at 40x magnification. Fisher’s exact test and Chi-square test were used in SPSS version 22.0 for analyzing data. A significant level of 5% was considered.

In the control group, no cracks were observed in any of the sections. At 3 and 9 mm from the apex, the ProTaper Gold group had the highest frequency of cracks and at 6 mm from the apex, the Edge taper platinum group had the highest frequency of cracks. There was no significant difference in the frequency of dentin cracks between ProTaper Gold and Edge taper platinum groups in any of the sections.

Both ProTaper Gold and Edge taper platinum systems caused the formation of dentin cracks. Preparation of root canals by Edge taper platinum and ProTaper Gold rotary files causes the formation of dentin cracks to the same extent.

A thorough understanding of tooth and root canal morphology is required for successful root canal treatment. The current study aimed to assess the canal and root morphology of maxillary first molars (MFMs) and maxillary second molars (MSMs) using cone-beam computed tomography (CBCT).  

In this cross-sectional study, CBCT scans of 400 patients were used. The number of roots and canals, as well as the morphology of the root canal system of MFMs and MSMs were assessed according to the Vertucci’s classification, separately sorted by gender and by using OnDemand3D dental software. To compare the variables, the Chi-square test was used with a significance level of 0.05.

All the MFMs and MSMs had three roots. The most common morphologies according to the Vertucci’s classification in mesiobuccal (MB) roots of MFMs were type II (43.1%), followed by types I (28.7%), and IV (19.8%); while, types I (63.5%) and II (18.7%) were more commonly found in the MB roots of MSMs. All distobuccal (DB) and palatal roots were type I. The frequency of the second mesiobuccal (MB2) canal in MFMs and MSMs was 71.3% and 36.6%, respectively. Gender had no significant correlation with presence of MB2 canal (P>0.05).

Three roots with four canals were the most common in MFMs while three roots with three canals were the most frequent in MSMs. Variations in MB roots were greater than in other roots. The frequency of MB2 in MFMs was greater than that in MSMs.

 Ectodermal dysplasia is a genetic condition that affects ectodermal derivatives such as skin, hair, nails, teeth and sweat glands. The disease is diagnosed at birth or in early childhood. Tooth developmental disorders are observed in different forms in these children. These disorders expose children to ridicule, which can lead to psychological problems; Therefore, the physical treatment of these children is very important, especially in the oral area. This report describes the appearance and dental treatments performed on a 6-year-old girl with ectodermal dysplasia.

Case Report:

 A 6-year-old girl with no systemic disease complained of a history of being ridiculed by her peers. Lack of deciduous and permanent teeth and conical teeth were visible in this child. The child had reduced, thin hair, hypotonic lips, and a dry mouth. The bridge of the nose also seemed concaved. The baby's teeth had no caries or periodontal disease. The treatment plan for this child included a composite build-up of the conical anterior teeth and then the design of a removable partial denture to preserve the space of the missing teeth as well as their replacement.

 Removable prostheses are a suitable treatment option for children with ectodermal dysplasia. After the age of 18, surgical treatments for implant placement and then placement of implant-based prostheses can be considered.

Critical thinking is a skill on which learner can achieve teaching goal during an  active  mental process only after receiving key point from teacher . This valuable skill is not considered as it should be in dental students, especially during the Covid-19 pandemic, when theoretical courses are held online therefore, the present study was conducted to evaluate the critical thinking skill of dental students of Mazandaran University of Medical Sciences during virtual education.

This descriptive cross-sectional study was performed on dental students of Mazandaran University of Medical Sciences in 1399-1400. Data collection tool was The California Form Critical Thinking Questionnaire consisted of 34 questions that were distributed online among 127 dental students. Collected data were entered into SPSS-21 statistical software and descriptive statistics, independent T-test and One-way analysis of variance were used to analyze the data.

117 people participated in this study. The mean score of critical thinking in the present study population is 12.48±4.06 Therefore, the critical thinking skills of dental students are poor. The mean score of critical thinking and each of its dimensions is not significantly different between male and female students.

It is thought that this skill has become weaker in students during the days of virtual education;

Obstructive sleep apnea (OSA) is a sleep-related respiratory disorder that has a relatively high prevalence among children and adults. OSA has several anatomical and pathophysiological etiologies and is characterized by recurrent periods of narrowing of the pharynx and airway, increased resistance to airflow, and decreased or interrupted airflow during sleep. This disease has several complications which lead to decreased quality of life. Once diagnosed, orthodontists are able to prescribe various methods to treat the disease. The aim of the present study was to review effective orthodontic treatments and their advantages and disadvantages in treatment of OSA. PubMed, Scopus, Web of Science, and Cochrane Library databases were searched for relevant articles published in English until April 30, 2022. Articles on orthodontic treatments in patients with OSA were included. After assessment of studies, 60 articles were included in current review. Findings showed that treatment with oral appliances is effective in OSA patients. Due to the unwanted dental and skeletal side effects of oral appliances in long-term use, it seems better to have this treatment performed by an orthodontist to regularly monitor the occlusion of the teeth and, if necessary, to change the settings of the appliances. In patients with severe OSA, it is better to evaluate the effectiveness of appliance therapy and, if needed, perform surgical treatments.

 Orthodontics is defined as a branch of dentistry that concerns the correction of malocclusion. In this regard, determining the most appropriate time for orthodontic treatment is of utmost importance. General dental practitioners (GDPs) are normally the first link of the treatment chain for patients requiring orthodontic treatment.

 The present study aimed to determine the GDPs’ knowledge of the appropriate timing of orthodontic treatment in Sari, Iran.

 This descriptive, analytical and cross-sectional study was performed on GDPs working in Sari in 2019. The statistical population included 380 GDPs, 186 of whom were selected. Data was collected using a 24-item questionnaire aimed to evaluate the GDPs’ knowledge level of the appropriate timing of orthodontic treatment. Data analysis was performed using SPSS version 19.

 In total, 142 out of 186 GDPs participated in the study with a mean age of 36.12 ± 10.15 years. 86 subjects (59.9%) had less than 10 years of work experience. Total mean (± SD) knowledge level of the GDPs was estimated at a moderate level (14.13 ± 3.79). Percentage of the knowledge levels considered as poor, moderate and good was 12, 70, and 18, respectively. There was a significant relationship between knowledge level and gender (P = 0.013). Meanwhile, no association was observed between the work experience of the participants and their level of knowledge (P = 0.393).

 According to the results of the present study, the total mean score of GDPs’ knowledge about the appropriate timing for orthodontic treatment in Sari was moderate, and only 12% of the participants had a poor knowledge level in this regard. It is notable that male subjects had a significantly higher knowledge level, and another analysis demonstrated the lack of effectiveness of work experience on the knowledge level of individuals.

In many universities, the physical presence of dental students is required to learn the theoretical sciences and clinical skills. These students are at a high risk to get infected with Coronavirus disease 2019 (COVID-19) because aerosol production and close contact with patients is inevitable. In this review study, the challenges in educating dental students during the COVID-19 pandemic and related solutions are discussed.

MEDLINE, Scopus, Ovid, and Google scholar databases were searched for relevant articles published in English until September 7, 2020. Articles with the target population of specialty/general dentistry students were included and studies associated with graduate dentists or other pandemics were excluded. After quality assessment, 49 studies were included in current review.

The COVID-19 pandemic caused disruption in traditional face-to-face dental education which was replaced by synchronous learning. This type of learning is faced with some challenges, including lack of sufficient facilities and lack of familiarity of involved people. In this situation, teaching and assessment of theoretical modules should continue virtually with high quality. Clinical units should also be organized by grouping students in smaller numbers and more shifts while adhering to new infection control protocols. Research can also be continued on animal models and COVID-19-related subjects.

Improving the structure of theoretical and clinical education in dentistry is recommended to deal with similar crises in the future.