مجله تحقیق در علوم دندانپزشکی
سال بیست و یکم شماره 2 (پیاپی 80، تابستان 1403)

With increasing concerns over the stochastic effects of x-ray radiation in dental radiography, effective education of dental students in this field is important. According to studies, educational softwares enhance learning, therefore the aim of this study was to develop an educational software for dental radiation protection and to compare its effectiveness against classic lectures in Islamic Azad University, Tehran Dental branch.

The study was exploratory in the first stage and a clinical trial in the second. Software was developed based on ADA guideline, using ScreenRecorder and MultimediaBuilder. 46 dental students who have never received any education on dental radiation protection were divided into control (N=22) and test (N=24) groups which have been matched based on the GPA and VARK test results. The test group used the software, while the control group attended a lecture. Students’ learning rates were evaluated by using 2 identical 10-question multichoice tests taken immediately and after two weeks. The results were analyzed in SPSS25 using the Mann-U-Whitney test, independent samples t-test, and Pearson's chi-squared test.

Educational software was developed successfully. In both exams, the mean score in the test group was higher than that in the control group by a statistically significant difference (p<0.001). The mean scores of test group and control group were 8.91±1.31 and 6.13±1.67 in the first exam and 6.79±1.69 and 4.90±2.09  in the second one respectively.

Multimedia educational software can improve learning of principles and methods of dental radiation protection in dental students.

an air void between the restoration and tooth because of Variable Environmental Pressure can lead to pulpal pain or fracture of the tooth or restoration.

60 molar teeth  divided to 2 groups. Preparation in Group A was a Cl V cavity in wich the Gingival margin was 1mm under CEJ while the occlusal margin was in  enamel. For Group B, we followed the same procedure plus a 0.5mm bevel with 45 degree angle in the enamel margin. Group A was filled with composite inlays of Filtek Z250 (3M ESPE, St. Paul, MN, USA). Group B was restored directly by the same composite.Each group were divided into control and case groups. The case specimens were put into 96 cycle pressure for 0 to 5 atm. Then the specimens were put in distilled water and were kept in silver nitrate solution. After washing them with water, they put in radiographic developer solution under fluorescent light. Finally, they were cut by a  diamond disc and the microleakage were studied under a stereomicroscope with 20X magnification. Data was evaluated using two-way nonparametric model

There was no significant difference between direct and indirect restorations, both in fixed and variable pressures in the occlusal walls. P=0.1 Besides, in both direct and indirect groups there was a significant difference in gingival wall between fixed and variable pressure, in a way that in fixed pressure, there was less microleakage. (P=0.000)

Changing in environmental pressure increase the microleakage in direct and indirect restorations.

The purpose of this study is to determine the effect of X-ray exposure in CBCT imaging on the amount of nuclear changes and repair index of buccal mucosa cells in the patients of oral and maxillofacial radiology department of Tehran Azad University in 2022.

he present study is an experimental research, comparing before and after, which was conducted on 63 eligible patients. Buccal mucosa cells were  examine. once before and once 10 days after X-ray exposure, Then Papanicolaou staining was used to measure the micronucleus and other nuclear changes and observation was done with a light microscope with 400× magnification. CBCT images by Papaya 3D Plus device (Genoray, Korea) with two FOVs, small (4 x 4 cm) and large (14 x 14 cm) and Voxel Size: 0.175 mm with exposure conditions of 60-90 kV and 4-12 mA were prepared.

Statistically significant increase in Micronucleus (p<0.001), Karyorrhexis (p<0.001), Karyolysis (p=0.01) and Broken egg (p<0.001) before and after X-ray exposure. But there is no statistically significant difference in the amount of Repair index (p=0.054)

The present study shows that CBCT imaging can induce cytotoxic and genotoxic effects on buccal mucosa cells. Therefore, CBCT should only be prescribed when necessary because it cannot be considered a risk-free procedure.

This research examines the effect of two antioxidants, pomegranate peel extract, and green tea, on the shear bond strength of microhybrid composite on bleached enamel using sixth-generation bonding.

44 premolar teeth were used in this study. The samples were divided into 4 groups, Group A: composite restoration without previous bleaching treatment. Group B: Restoration of teeth immediately after bleaching treatment. Group C: Bleaching treatment, then using 5% green tea extract as an antioxidant on the tooth surface, followed by tooth restoration. Group D: Bleaching treatment, then using 5% pomegranate peel extract as an antioxidant on the tooth surface, followed by tooth restoration. For the restoration, the 6th generation Bond SE (Kuraray Dental, Japan) and micro-hybrid composite (3M ESPE, USA) Filtek Z250 were used. To measure the strength of the shear band, the Zwick universal testing machine (Berlin, Germany) was used, and at the end, the types of failure were examined using a stereomicroscope. Calculations were done using PASS II and SPSS 25 software, OneWay ANOVA, Tukey, and homogeneity of variance tests.

No significant difference was observed between groups A, C, and D (P>0.99), but between these groups and group B, the amount of shear band strength was significantly different (P<0.001).

 The use of 5% pomegranate peel extract and green tea increases the shear bond strength of composite to bleached teeth.

Dental caries is the most widespread chronic disease ,in which bacterial plaque plays a major role in their occurrence. Considering the importance of dental plaque control, side effects of chemical products, availability of medicinal plants in the ecosystem of our country, therefore this study was conducted with the aim of comparing the effects of Ferula gummosa plant and chlorhexidine on cariogenic bacteria.

In this laboratory study, the aerial parts of the plant were collected from Tarom/Zanjan region. Herbarium sample identification was done by Zanjan Faculty of Pharmacy.The essential oil of Ferula gummosa was obtained by Clevenger apparatus and prepared by distillation with water. Serial dilutions of essential oils were prepared and the minimum inhibitory concentration and the minimum lethal concentration were determined. Disk diffusion method was used to evaluate the antibacterial effects of essential oilon the tested bacteria (Streptococcus mutans, subrinus, salivarius and Lactobacillus acidophilus). In order to evaluate bacterial sensitivity to essential oil and chlorhexidine, well plate method was used. The dates were entered the computer by the SPSS 22 software aand analyzed by independent Ttest.

In some samples, the antibacterial properties of Ferula gummosa were similar to chlorhexidine. Ferula gummosa plant extract had the most effect on Streptococcus subrinus and Salivarius. The diameter of the inhibitory zone in Streptococcus subrinus bacteria was non-significantly greater than that of chlorhexidine.

The antimicrobial effect of Ferula gummos essential oil on cariogenic bacteria was similar to chlorhexidine. It is recommended to use the compounds of this plant as an alternative to other chemical products (mouthwash and toothpaste).

Oral infections caused by Candida species are increasing worldwide. One of the common topical treatments related to oral candidiasis is nystatin, which has anti-fungal and antimicrobial activity. Common anti-fungal treatments have many side effects and cause drug resistance and repeated recurrence of Candida infection. The use of plant extracts can be a suitable alternative to synthetic drugs such as nystatin. The aim of this study was to compare the anti-fungal effect of Nigella Sativa with nystatin on Candida albicans.

An experimental study was conducted by referring to the Scientific and Industrial Research Organization of Iran and the standard strain of Candida albicans with PTCC5027 was provided. Ethanol soaking method was used to obtain the Nigella sativa ethanolic extract. Fungal suspension with 0.5 McFarland concentration was cultured in a broth medium. To investigate the anti-candida properties of the Nigella sativa Linn ethanolic extract , Disk diffusion technique was done in a Potato dextrose agar by uniformly inoculating the fungal suspension on the culture medium of potato dextrose agar then using a 100 μl micropipette, the Nigella sativa Linn extract with a concentration of 100 mg/ml and Nystatin in a dose of 0.06 mg was poured on a sterile blank disk and put in the plates and , subsequently the growth inhibition zone of the extract was measured. By diluting the extract and nystatin to  0.09, 0.19, 0.39, 0.78, 1.56, 3.12, 6.25, 12.5, 25.50 the Minimum Inhibitory Concentration (MIC) and the Minimum fungicidal concentration (MFC) were obtained using both Microdilution broth and Macrodilution broth. Each experiment was repeated 3 times and the obtained data were statistically analyzed using SPSS ver:25 software and t-test exam.

The length of the inhibition zone measured from the Nigella sativa Linn extract was 19.5mm respectively and the length of the inhibition zone obtained by Nystatin was 24.5 mm respectively. Studying the results of the dilution test in both techniques concluded from the Nigella sativa Linn extract showed that the Nigella sativa Linn ethanolic extract at a concentration of 1.56 mg /ml has the least Minimum Inhibitory Concentration (MIC) and at a concentration of 3.12 mg/ml it has the lowest Minimum Fungicidal Concentration (MFC). Statistical analysis (T-test) showed that the difference in length of the Nigella sativa Linn inhibition zone with Nystatin (P <0.05) was significant.

According to our findings, it seems that the Nigella sativa Linn ethanolic extract is quite effective on the growth of Candida albicans and has an antifungal effect. However, the antifungal effect of Nystatin is significantly higher than the Nigella sativa Linn ethanolic extract.

maxillofacial structures are usually affected in motorcycle crashes .So the aim of this study was to evaluate helmet using on the frequency and patterns of  maxillofacial fractures.

In this descriptive cross-sectional study ,records of 181 patients hospitalized for maxillofacial fractures in Shiraz Shahid Rajae Hospital during 2016-2020were evaluated. Demographic and clinical variables included age, gender, type of fractures based on single or multiple and the location of the fractures in the mandible and the middle area of the face were recorded for each patient. The data were analyzed by  chi-square test(P <0.05).

Out of 181 patients,%77.2 of patients were male and  %22.8 were female.  Significant difference between helmet using and gender and age groups were observed. P= 0.012 In motorcyclists with helmet in comparison to without helmet,fracture in middle face area was lower than mandible.Frequency of single and multiple fractures were %39.3 and %60.7 respectively. The highest frequency of middle face area and mandibular fractures were in lefort II and body of mandible respectively. The lowest frequency of middle face area and mandibular fractures were in nasal bone and ramus respectively .Against mandible, there was a significant relationship between helmet using and middle face area fractures. (P=0.011)

helmet using can reduce maxillo facial fractures especially in middle face area.

  Better and higher adaptation of students to the college environment can have a significant impact on the academic performance of individuals and ultimately their academic progress. The purpose of this research is to investigate the personality traits that affect the academic adjustment of dental students in Tehran Islamic Azad University of Medical Sciences in 2021-2022.

This descriptive research was conducted on randomly selected students. Two questionnaires were used: 1: Anderson academic adjustment 2: HEXACO 6-factor model. The questionnaires also contained demographic information such as (age, sex, year of education, marital status). Kruskal-Wallis test was used to investigate the relationship between academic adjustment and subgroups of personality traits, and the role of variable factors was determined by regression analysis. All calculations were done using SPSS software version 26.

The average academic adjustment score among 250 participating students was 34.3 ± 2.582. The average score of honesty-humility, excitability, extroversion, pleasantness, openness to experience, and conscientiousness personality traits were obtained as 11.97, 10.19, 13.49, 10.40, 13.55, and 13.85 respectively. There was a positive and significant relationship between personality subgroups, extroversion and conscientiousness with compatibility, and between personality subgroups, excitability and agreeableness, there was an inverse and significant relationship with compatibility (p<0.05).

 It seems, status of academic adjustment for dental students of Tehran Islamic  Azad University was suitable Extraverted and dutiful had more academic adjustment and excited and negotiable ones had less adjustments.

Early diagnosis and referral of patients with oral cancer can help reduce mortality, and given that dentists are usually the first group to see oral lesions, it is therefore in an ideal position for early cancer screening..
The aim of this study was to investigate the knowledge and attitude of clinical students of Yazd Dental School about oral cancer in the academic year 1300-1499. 

  This study was performed on 160 students of 4th to 6th academic semester of Yazd dental school. The questionnaire included demographic information including age, sex, academic semester and average, and questions about knowledge and attitudes about oral cancer. Data were entered into SPSS23 and analyzed using ANOVA, T-TEST.

  The mean score of knowledge and attitude was 4.85 ± 2.88 out of 10 points and 39.53 ±  4.19 out of 50 points. Knowledge had a significant relationship with age but had no significant relationship with gender, academic year and average. attitude had no significant relationship with any of the variables.

  Students' knowledge and attitude about oral cancer is insufficient and there is a greater need for education in this field, so a review of the curriculum and more practical experience to improve education and approaches to change attitudes should be considered

Pigmented lesions appear with different manifestations in focal, multifocal and diffuse forms and can also be a symptom of a systemic disease. These lesions have a significant prevalence in the head and neck area. The aim of this study was to determine the prevalence of pigmented lesions in the head and neck region in patients referred to Razi Hospital in Tehran.

A cross-sectional descriptive study was conducted on 3000 archived files in Razi Hospital in Tehran in 2018 and 2019. All pigmented lesions in patients under 18 years of age were isolated and analyzed in terms of age, gender, location and histopathological diagnosis. Data were analyzed using SPSS version 26 and Chi-square and T-test statistical tests. The significance level of statistical tests was considered less than 0.05.

A total of 138 patients under 18 years of age were found with pigmented lesions 56 patients were male (40.6%) and 82 patients were female (59.4%). The average age of the patients was reported to be 11.1 ± 4.6 years. Meanwhile, compound nevus and intradermal nevus lesions were the most prevalent. The most involved sites were cheek (29.7%), nose (16.7%) and head (15.9%). A total of 6 cases of malignant pigmented lesions were found (4.3%).

Nevi types are the most common pigmented lesions in this age group and more frequent in check area.