مجله دانشکده دندانپزشکی مشهد
سال سی و هشتم شماره 4 (پیاپی 91، زمستان 1393)

Teachers play an important role in an educational system. According to the importance of this subject in education quality improvement, the purpose of the present study was to compare the students’ and teachers’ viewpoints about the characteristics of a good teacher in dentistry. In the first step, an open- close questionnaire was prepared based on a ten person focus group discussion by the students composed of teachers’ characteristics in theoretical and clinical courses and evaluation. The questionnaire was based on four point Lickert scale and was presented to 100 clinical students and teachers of Mashhad dental school after reliability proof process in a Test retest evaluation. The data were analyzed by SPSS software. (α=0.05) In the first part, teachers’ and students’ most important choice was" teachers’ ability to integrate basic and clinical concepts" with the mean of 3.58 and 3.54 respectively. In the second part," discuss about the students’ concept in treatment plan" was the most important factor among teachers and students with the mean of 3.63 and 3.29 respectively and in the third part," evaluation designing based on a general dentist needs" was the most important factor among teachers and students with the mean of 3.02 and 3.32 respectively. The viewpoints of teachers and students were the same except for the level of importance of four subjects (teachers attending in classroom on time, paying more attention to patient management, introducing a hand out in courses and giving high lesson scores to all students) The results of the present study showed that the viewpoints of the students and teachers of Mashhad dental school about the characteristics of qualified teaching were the same in most of the subjects.

Exam is an inseparable part of education and the main tool to evaluate the results of educational process. If based on scientific rules, it can show the level of achievement to educational goals. This study was accomplished to evaluate the quality of theoretical exams in different departments of Dental School, Shahid Beheshti University of Medical Sciences In this cross-sectional study, the quality of all written final exams of the first theoretical courses of 10 departments were evaluated in terms of 30 indices regarding structural validity, content relevance and content coverage, differential index, difficulty index, value of distracters, and taxonomy. Millman's check list, content analysis table and standard formula were used to collect the data. SPSS software version15 was used to analyze the data. Out of 544 questions, 67.5% were multiple choice questions, 13% were descriptive and 19.5% were true–false queries. Content relevance and content coverage was considered in 85.4% and 84.5% of questions respectively. Standard structural rules were observed in 96.4% of questions and 72.2% of exams. Difficulty index and value of distracters were estimated to be 67.8%, 22.3%, and 24.5% respectively. 84.6% of questions were of taxonomy I, and the remaining 15.4% were of taxonomy II. Content relevance, content coverage, consideration of structural rules, and difficulty index were acceptable in theoretical written exams, whereas taxonomy, differential index and value of distracters needed to be reconsidered.

In recent years, importance and researcher's enthusiasm of evidence-based studies has increased; thus, a survey and verification of previous studies is needed. In spite of the importance of descriptive epidemiological studies, a few critical appraisals and verifications have been done. To address this necessity, this paper aimed to survey and critically appraises dental epidemiological studies. Dental descriptive epidemiological studies in Iran published between 1996 and 2009 were selected and scored based on standard instruction consisted of eight criteria as following: 1) Sampling method, 2) Sampling frame, 3) Sample size, 4) Appropriate Measurement, 5) Unbiased measurement, 6) Response rate, 7) Confidence intervals, 8) Study subjects description. Among 91 papers, the maximum score was related to "Study subject’s description" that 72 papers obtained it. In contrary, the minimum score was related to "Response rate" which only 2 papers obtained it. Surprisingly, the average total score of the 91 papers was only 2.64 out of 8. In these studies, the common mistakes were non-random sampling, unidentified sampling frame, and vague method of sample size computation. In spite of correct measurement criteria, most of the studies had not described them clearly. To conduct epidemiological studies which provide a clear and documented description of a real situation, improving the quality of the papers seems necessary. Considering the neglected criteria and correction of common mistakes are essential; Consequently, the future studies may present correct, trustworthy, and clear status of the problems.

The purpose of this study was to evaluate the effect of spreader penetration depth and its alloy on apical microleakage using lateral compaction method. For conducting this in vitro lab study, 68 extracted maxillary central incisors were instrumented using the step-back method, and randomly divided into the following four experimental groups: A) stainless steel (S.S) spreader with penetration to the working length B) Nickel-titanium (Ni-Ti) spreader with penetration to the working length C) S. S spreader with penetration 1mm short of working length D) Ni-Ti sprader with penetration 1mm short of working length. Microleakage evaluation was conducted using dye penetration method. Data were statistically analysed by Two-Way ANOVA test. The data showed that the least dye penetration happened in group D. There were significant differences in mean microleakage among the groups (P=0.002). Conclucsion:According the results of this study, it seems that spreader alloyand its penetration may have a role in the amount of apical microleakage. However, before recommending Ni-Ti spreaders, further in vivo and in vitro studies should be carried out.

Herbal extracts have been used in disease treatment for many years. Although in traditional medicine, Teucrium polium is used in treatment of inflammatory conditions, rheumatism and ulcers, there are no studies about this herb in dental field as a mouthwash. The aim of thisstudy was to evaluate Teucrium polium mouthwash effect on salivary Streptococcus mutans count as the main microorganism responsible for dental caries. In this crossover double-blind randomized clinical trial, 22 dental students participated and were randomly divided into two equal groups. Teucrium polium and placebo mouthwashes were prepared. The salivary Streptococcus mutans counts were determined in participants. The first group used Teucrium polium and the second group used placebo for two weeks and the salivary samples of both groups were collected again. After a wash out period of three weeks, the first group used placebo and the second group used Teucrium polium. In each group, the salivary counts of Streptococcus mutans were determined before and 2 weeks after the use of mouthwashes. Data were analyzed using paired t-test and independent two-sample t-test. was considered as statistically significant. There was no significant difference between the colony counts before the use of mouthwashes in two groups (P>0.050). Use of Teucrium polium mouthwash significantly decreased the number of Streptococcus mutans colonies in comparsion with the placebo group (P<0.010). Considering the limitations of this study, Teucrium polium mouthwash may decrease the number of Streptococcus mutans colonies in saliva.

Oral contraceptive pills are one of the most widely used methods in the field of population control, and this method is safe, effective and available. On the other hand, oral hormonal contraceptive use in reproductive ages is considered as a risk factor for periodontal disease. We decided to investigate the effect of this product on the amount and type of subgingival bacteria. This case-control study was conducted on 44 women who were 15-35 years old using oral contraceptive pills and 44 women at this range who didn’t consume such pills. First, subgingival sampling was conducted from the deepest pocket in each quadrant. Then samples were transferred to a solid medium for detection of anaerobics including Actionbacillus actinomycetemcomitans (A.a), Porphyromonas gingivalis (P.g) and Prevotella intermedia (P.i) using morphological test and biochemical characteristics. Finally, the data were collected and subjected to independent t-test. The data showed that in subjects who used contraceptive pills, A.a, P.g and P.i decreased significantly as compared to subjects who did not use contraceptives and had the same level of oral hygiene (P<0.001, P<0.001 and P=0.03 respectively). The present study showed that women who consume contraceptive drugs, average number of anaerobic colonies, A.a, P.g and P.i increased significantly.

In spite of recent advances in cancer treatment, the oral cancer is still one of the top ten causes of death because of late diagnosis and due to various reasons such as being asymptomatic in early stages, similarity of its clinical presentation with other lesions and variety of clinical manifestations. Considering the role of environmental and geographical factors in cancer incidence, epidemiological studies are of great importance. The aim of this study was to determine eight year prevalence of oral and paraoral malignancies of the patients referred to Bou-Ali-Sina hospital as the center of head and neck malignancies in Sari, Iran. In this study which was performed on 43 medical files of patients with oral, paraoral and maxillofacial malignancies from March 2005 to March 2013, necessary individual, clinical and histopathological information were extracted. SPSS 18 software was used to analize data and draw tables and charts. Squamous cell carcinoma (SCC) was the most common malignancy (32.2%) followed by Basal cell carcinoma (30.2%) and Metastatic tumors (6.9%). Male to female ratio was 1.5/1 and age average was 55.04±17.56. The most common clinical feature of SCC was exophytic lesion (50%), followed by ulcerous lesion (42.8%). Basal cell carcinoma mostly appeared with ulcer (62.5%) and other malignancies mostly appeared as exophytic lesions (%51.1). The most common site of SCC involvement was neck (42.7%) while BCC was totally observed on facial skin (100%), and the most common site in other malignancies was neck as well (37.5%). Most of the epidemiological patterns of oral squamous cell carcinoma were different and less prevalent from other studies. Males had higher incidence rate than females and surprisingly using tobacco had a weak role as a risk factor.

The aim of this study was to evaluate educational curriculum in the community dentistry and oral health department of Mashhad dental school using the CIPP (Context-Input-Process-Product) model in 2013. In this cross - sectional study, data were collected using a self-administered questionnaire which was designed using CIPP Evaluation Model check List. Four domains including Context, Input, Process and Product of educational curriculum at the community dentistry and oral health department of Mashhad dental school were evaluated based on the viewpoints of its staff and students who had passed the related practical course. The sum of acquired scores was computed separately in each domain. The scores were categorized in 0-50 as unfavorable, 51-70 as partly favorable, and 71-100 as favorable. For comparison of mean scores of three groups of students who had passed practical community dentistry courses 1, 2 or 3, ANOVA statistical test was used. Mann-Whitney test was used for comparison of mean scores of staff and students in each domain. There were no significant differences in mean scores of domains of Context (P=0.91), Process (P=0.11), and Product (P=0.3) among students who had passed practical community dentistry courses 1, 2 or 3. However, a significant difference in Input domain was found among students (P=0.009). In Context (P<0.001), and Process (P=0.001) domains, there was a significant difference between staff and students’ scores. However, no significant difference was observed in the Product domain. In domain of Input, there was a significant difference between staff and students of practical community dentistry course 1 (P=0.03). From students’ view point, Context, Input, and Process domains of Community dentistry and oral health department of Mashhad dental school educational curriculum were partly favorable and Product domain was unfavorable. From staff view point, Context domain was favorable whereas Input, Process and Product domains were partly favorable.

Panoramic radiographs taken for dental purposes provide an opportunity for dentists to identify non-symptomatic maxillary sinus abnormalities. The aim of this study was to evaluate the frequency of mucous retention cysts (MRCs) of maxillary sinus and some associated risk factors in the patients attending to the dental faculty of Guilan. In this cross-sectional study, digital panoramic radiographs of patients referred to the department of radiology, dental school of Guilan, from October 2012 to October 2013 were evaluated. A total of 800 digital panoramic radiographs (200 for each season) were evaluated by one oral and maxillofacial radiologist to detect MRC in maxillary sinus. Frequency of MRC and some associated risk factors were assessed. Statistical analysis of the data was performed by Chi-square test. Among the 800 evaluated digital panoramic radiographs, 444 subjects were females (55.5%) and 356 were males (44.5%) aged 8 to 81 (36.02±14.71) years. The frequency of the MRC was 4% (32 radiograghs). Of 32 maxillary sinus MRCs, 13 (40.625%) were right-sided, 13 (40.625%) were left-sided and 6 (18.750%) were bilateral. Although, MRC presented no statistically significant correlation to age (P=0.444), the highest frequency was seen in fifth (6.1%) and third (4.7%) decades. Frequency in males (6.2%) was significantly higher than in females (2.3%); (P=0.005). The highest frequency of MRC was detected in spring (7.5%) and autumn (5%). In this study the frequency of MRC in males was higher than in females and was seen mostly single and unilateral. Also the highest frequency of MRC in spring might emphasize the effect of allergic factors on MRC prevalence, mentioned in some previous studies.

Some parts of orthodontic treatments, especially in the field of prevention-intervention are defined as general practitioner's responsibility. The aim of this study was to evaluate orthodontic treatments provided by general practitioners in Shiraz. In this cross-sectional and descriptive study, a 12-item questionnaire was sent to 115 general dentists selected through stratified random sampling. The questionnaire was designed for gathering the data about the demographic characteristics of the dentists and their orthodontic treatments. The data were analyzed using SPSS software and Chi-square test. More than half of the recipients reported that they have provided no orthodontic treatment. The most common malocclusions treated by the practitioners were crowding and spacing and space maintenance. A slightly more than 10% of the participants used Edgewise or Straight wire techniques for fixed treatments. The majority of the respondents reported that they received most of their orthodontic knowledge during undergraduate dental training and most of them evaluated the quality of orthodontic training as "Poor" during this course. Practitioners with fewer years of experience provided more orthodontic treatments than the others. Changes in the undergraduate educational system and workshop set ups can be considered as solutions to improve dentist's orthodontic skill and knowledge in preventive - interceptive orthodontics.