مجله تحقیق در علوم دندانپزشکی
سال بیستم شماره 4 (پیاپی 78، زمستان 1402)

 PGE2 plays a very important role in the mediation of orthodontic therapies and dental reactions. Laser therapy in dentistry can be used to reduce pain, increase genetic bone, stimulate teeth, and reduce localized pain in time periods. The purpose of this study was to determine the effect of low-power laser therapy on the surface of PGE2  gingival fluid during orthodontic treatment.

 In this double blind clinical trial study, 15 patients with crowning or protrusion of teeth requiring constant orthodontic treatment, along with pulling of the first two right and left prime mules, and then retracting the anterior teeth, were selected. After the first periodontal period examinations was performed in patients undergoing orthodontic treatment. One quadrant was selected as the experimental group and the opposite quadrant was selected as the control group. In the experimental group, low power diode laser irradiation was performed along the entire length of the gingival groove on days 0 (start of treatment), 2, 18 and 30 (total 4 days) after orthodontic treatment and sampling. The samples were transferred to the laboratory and determined at PGE2 level using an ELISAR device. Data were analyzed by Repeated Measure test, Friedman test and paired t-test.

 The mean the PGE2 fluid in the orthodontic treated teeth, In the days of treatment, 30,18,2 laser radiation was significantly different between the experimental and control groups (P <0.001). In laser therapy, with significant increase in time, there was a significant reduction in PGE2 (p<0.05).

 Regarding the effect of reducing the pain of using and not using the laser in orthodontic movement, adjuvant treatment with low power laser reduces PGE2 as a mediator causing pain

Nowadays, color matching is one of the most challenging issues in dental restorations and cosmetic dentistry. As natural teeth have a wide range of colors, the proportionality of restoration or prosthesis to the remaining teeth, especially in the anterior region, is important. This study was conducted with the aim of comparing two digital devices in determining the color of ceramic samples based on the reference system of spectroradiometry.

 This laboratory experimental study was performed on 48 ceramic samples of A1, B1, C1, and D2 feldspathic ceramics, with six disks of each color, according to the Vita classic shade guide with a diameter of 0.12±0.5 mm and a thickness of 2±0.5 mm. Each of the three digital devices, Vita Easyshade, 3Shape TRIOS3, and CS2000, were calibrated according to the manufacturer's instructions before starting work. In this color evaluation, each ceramic sample was matched with the reference system of CS2000 based on l, a, and b values. Then, ceramic samples were color matched with Vita Easyshade and 3Shape TRIOS3 devices based on CIE lab and Vita classic. The difference in color determination by the three digital devices compared to the reference system was evaluated by SPSS version 26 software and chi-square test (p<0.05).

 The 3Shape TRIOS3 group had a 66.7% error rate, while the VITA Easyshade V group had a 25% error rate. The difference in the false measurement rate between the two methods was significant (p<0.005), and using the 3Shape TRIOS3 device increased the chance of error by 2.667 times (O.R=2.667).

 Determining color with the VITA Easyshade V device is better and more accurate than determining color with the 3Shape TRIOS3 device.

  Recurrent Aphthous Stomatitis (RAS) is a disorder characterized by recurrent ulcers limited to oral mucosa in patients who have no other symptoms of systemic disease. The main factors currently associated with RAS include genetic factors, hematological defects, immunological problems and local conditions such as trauma and smoking. The aim of this study was to evaluated serum vitamin D levels, neutrophil to lymphocyte ratio and mean platelet volume in patients with RAS.

 In this case control study, 30 patients with RAS and 30 healthy individuals were compared as controls, serum samples were evaluated for vitamin D, neutrophil to lymphocyte ratio and mean platelet volume. Findings were analyzed by Mann- Whitney and sample-t-test.

 Serum vitamin D levels in patients with RAS were 21.44±12.09 ng/ml  and in healthy individuals were 24.87 ±18.65 ng/ml . Also neutrophil to lymphocyte ratio in patients with RAS were 1.89± 1.23  and in healthy individuals were 2.03± 1.79. Mean platelet volume in patients with RAS were 10.36± 0.93 fl and in healthy individuals were 10.65 ±1.12 fl . There was no significant difference between the two groups. All three markers were not significantly different between the two groups. respectively (P=0.4), (P=0.8) and (P=0.27)

It seems that serum vitamin D levels and neutrophil to lymphocyte ratio and mean platelet volume not statistically significant in patients with RAS and healthy individuals.

Teaching and learning through peers during education can encourage students towards this type of teaching and learning and improve their practical and theoretical skills. The determination of the attitude of oral and maxillofacial surgery residents about the quality of efficacy of peer learning.

This qualitative study was conducted on 8 oral, maxillofacial surgery residents from the first to the fifth year studying at the Faculty of Dentistry of Tehran Islamic Azad University of Medical Sciences in the academic year of 2022-2023. A semi-structured questionnaire including areas of practical skills, theoretical knowledge, communication skills, mastery of college rules and regulations, and job skills was designed by the researcher. Assistants' attitudes were measured through interviews and their answers to questionnaire questions were reported.

  The results showed that in all topics of basic science group education, Ground Round meetings, and in Minor surgery teaching was done by professors to residents. In some cases, if professors are assigned to perform surgery, the training process takes place under the supervision of the senior year. Senior assistants believed that at the beginning of their training in the hospital, due to the lack of access to professors, their training was done through assistants. In most cases, training was done by observation and peer teaching process did not happen. In the discussion of integrating peer learning into the educational curriculum, the residents' opinions were that despite the usefulness of this teaching method, forcing to use it, especially tying certain topics for teaching in this way, cannot be useful.

The results of this research indicate the need for educational institutions and universities to pay more attention to student-centered educational methods such as peer learning, because the use of these methods can complement the teacher's teaching by providing a positive experience and lasting and deep learning.

 Enterococcus faecalis, play a significant role in plaque formation and tooth decay. Mouthwashes are one of the tools used to reduce decay..the aim of study was comparision of fluorine total with chlorhexidine on Enterococcus faecalis.

 In this in-vitro study a total of 24 samples (18 samples in each groups and 6 control samples) were examined, the diameter of the growth inhibition zone of Enterococcus faecalis was compared between two mouthwashes of fluorine total and chlorhexidine 0.2% Enterococcus faecalis was first cultured on a blood agar plate and incubated for 24 hours at 37 ° C. The bacteria were then cultured on 18 plates of blood agar (9 plates for chlorhexidine mouthwash and 9 plates for fluorine total mouthwash). To evaluate the absence of bacterial inside the mouthwashes, 2 plates containing fluorine total and chlorhexidine mouthwash were cultured separately. The plates were prepared by well method, then the growth inhibition zone in the two study groups was measured and analyzed by Repeated Measure ANOVA test of 25th version of SPSS software.

 The growth inhibition zone in the chlorhexidine and fluorine total group was 15/94±0.8 mm and 18/61±1.4 mm, respectively, which was in the chlorhexidine group, which is statistically significant (P<0/0001).

 Fluorine total mouthwash is more effective than chlorhexidine mouthwash on enterococcus faecalis.

Many Afghans prefer Iran for migration due to the similarity of language and neighborhood. This study was conducted in order to evaluate the oral health status of the Afghan population living in Iran and the barriers to their access to dental services.

By using a researcher-made questionnaire and with the help of 4 calibrated researchers (Iranian and Afghan); referred to dental centers. The selfmade questionnaire included 14 questions about oral health status, as well as questions about barriers to accessing to dental services.

Out of 742 participants in the study, 461 people preferred the clinic to the dental office for economic reasons. 483 people found dentist based on their compatriots' opinion and 545 people were deprived of government dental services because they did not have Iranian citizenship. 691 people had problems in paying dental fees and 588 people said that they had their teeth extracted due to economic problems. 594 people felt that they were discriminated in receiving services, and 588 people stated that the reason for the visit was an emergency.35 people went to the dentist for a check-up and 87 people stated that it was difficult for them to find a dentist. 238 people were inclined to use supplementary insurance. The average DMFT in the Afghan population was 6.22. No significant relationship was found between the DMFT and gender and residence history.

The level of oral health of immigrants is low and it is difficult for them to access dental services and insurance. The possibility of tooth extraction instead of keeping it is high in immigrants due to economic problems.

 Knowing study and learning strategies is a basic step for educational interventions, especially in the field of medical sciences. This study was conducted with the aim of determining the study and learning strategies in the dental clinical course students of Islamic Azad University of Tehran in the academic year of 2021-2022.

 This cross-sectional descriptive study was conducted on all students from the 5th to 12th semesters of the faculty of dentistry of the Islamic Azad University of Tehran (n=141). The Third English edition of the study and learning strategies Instruments(LASSI) questionnier was completed by the students after  cross- culture adaptation and confirming its face validity, quantitative content validity and construct validity and reliability was observed by test – retest. Data analysis was done using SPSS software and descriptive statistics, regression and Pearson correlation coefficient.

 The average score of study and learning strategies in dental students was 123.05±9.00 out of 240 scores with a minimum of 104 and a maximum of 148. The highest average score of study and learning strategies was related to the areas of concentration, selection of the main idea, and processing, respectively. The lowest average score of study and learning strategies was related to the fields of attitude, motivation and anxiety, respectively. The average score of study and learning strategies in dental students had no significant relationship with gender and marriage of students (p<0.05). But there was a direct and significant relationship between the average score of study and learning strategies with age (p<0.05). Also, there was a direct and significant relationship between the average score of study and learning strategies and academic performance (p=0.048, r=0.350).

 The average score of study and learning strategies in dental students indicated moderate scores  revision. It seems that dental students need counseling and guidance in some areas of study and learning strategies, especially in the areas of anxiety, attitude and motivation

  Vesiculobullous diseases (VBDs) are a category of disorders resulting from the production of antibodies against the connection of epithelial cells to each other and the underlying connective tissues. The prevalence of these diseases in individuals under 18 years old is significantly lower than in adults, and limited studies have specifically addressed the frequency of these lesions in this age group. This study aims to assess the prevalence of VBDs in patients under the age of 18 at Shahid Beheshti Dental School and Razi Hospital in Tehran from 2010 to 2020 based on age, gender, location of involvement, clinical diagnosis, and histopathology.

 A descriptive cross-sectional study was designed based on the available data in the archives of Shahid Beheshti Dental School and Razi Hospital from 2010 to 2020.

 A total of 2021 cases of VBD were identified, with 29 cases (1.45%) observed in individuals under the age of 18. Lesions showed a slight preference for females, with a female-to-male ratio of 1.23. Adolescents (13-18 years old) were the most affected age group (51.72%). The combination of lesions on the trunk and oral cavity was the most common combination observed in this study (44.82%). Pemphigus vulgaris (PV) (27.58%) was the most prevalent type of VBD, followed by erythema multiforme (EM) (24.13%), epidermolysis bullosa (EB) (20.68%), and bullous pemphigoid (BP) (17.23%).

 In summary, PV was the most common type of VBD in our study region, predominantly affecting females. EM and EB had the highest frequencies, with EB being the most common lesion in the birth to 5 years age group. BP had a lower prevalence in these age groups compared to the general population.

 The management of medical emergencies in dentistry is an important issue. The purpose of this study is to evaluate the knowledge, attitude and performance of Ahvaz dental students regarding medical emergencies in the dental office.

Methods and material: 

The present study was a descriptive study that evaluated 202 dental students. The data collection tool was a questionnaire consisting of 21 questions, which was prepared using other similar researches. The validity of the questionnaire was determined by the opinion of 5 specialists in the field of oral medicine. The reliability of the questionnaire was calculated by calculating the Cronbach coefficient of 0.75 . This questionnaire consisted of three parts: awareness, attitude and self-confidence. Questionnaires were completed in person by referring to the educational departments. The data were analyzed with the help of SPSS 24 software and Anova Analytic test.

 Self-confidence of male students in emergency medical situations was more than that of female students and it was statistically significant. There was no significant difference between male and female students' awareness of medical emergencies such as foreign body aspiration, anaphylactic shock, seizures, etc. (p = 0.835), while this awareness had a significant difference based on the year of admission(p=001/0). The results showed that syncope was the most frequent among emergency conditions experienced by students.

 It seems that all students are weak in facing some serious emergency situations such as cardiopulmonary arrest, which requires high awareness and self-confidence to perform CPR, and the students of lower years lack sufficient knowledge about all emergency situations.

 Vitamin D is a steroid hormone that is obtained primarily from exposure to sunlight, as well as from diet and supplements. This vitamin plays an important role in calcium phosphate homeostasis and bone turnover, and as a result, the musculoskeletal system. This vitamin is also effective in the immune system.

In this study we reviewed the related articles and books published in English between 2010 and 2023 in PubMed, Medline, and Google Scholar and searched the Scopus databases electronically using the keywords "vitamin D", "teeth", "oral manifestations", "Vitamin D deficiency" and "Dentistry".

 By reviewing related articles about the role of vitamin D in different structures of the body, including oral cavity, and the effects of its deficiency in the occurrence of diseases and the use of its supplements in the recovery of diseases, it seems  that this vitamin plays a significant role in the oral health and the immunity. There are conflicting results regarding the effect of vitamin D on external root resorption in orthodontics and Sjogren's syndrome. Hence, clinical trial studies are required for confirmation.

Fibro-Osseous-Lesions (FOLs) in jaws have been considered as one of the most important diagnostic challenges. FOLs are benign lesions in which part of the normal jaws bone is replaced by mineralizing fibrotic connective tissue. Different types of FOLs have some differences in etiology, treatment and prognosis but they may show similar in radiographic and microscopic view. Furthermore, they may also have microscopic similarities with some low-grade malignant lesions of the jaw. Therefore, in this review, we have tried to bring this always challenging story to a good and practical conclusion by providing specific and practical indicators for more accurate diagnosis of these lesions by examining the most important related studies.

Evaluated studies were in the range of 2011 to 2021. Our criteria for entering the study were associated researches with diagnostic challenges of FOLs and purposes of the study include: determining the connection among the clinical and pathologic FOLs, distinguishing various diagnostic challenges of FOLs from each other and malignant bone lesions.

The results of this study declare that accurate and correct diagnosis of FOLs requires a connection between clinical, radiographic and histopathological data.