مجله دانشکده دندان پزشکی اصفهان
سال پانزدهم شماره 3 (پیاپی 68، پاییز 1398)

Medical emergencies are one of the most stressful situations in a dental office. The first and the most important step in managing the medical emergencies is the ability to provide basic life support, which requires knowledge, experience and equipment. The aim of this study was to evaluate the emergency equipment and drug status and the ability to use them by general dentists in three cities in Isfahan Province. The current cross-sectional descriptive study was conducted by referring to 85 general dental offices with a questionnaire. Data were analyzed with SPSS 23, and the results were reported in the form of the means for quantitative data and in the form of frequencies for qualitative data. In addition, independent t-test was used to assess statistical relationships at a significance level of (p value < 0.05). Based on the results, 39.7% of dentists had encountered emergency events during the previous year, with vasovagal syncope as the most frequent of them. Hydrocortisone (35.6%) and nitroglycerin (32.8%) were the most common emergency drugs and an oxygen tank (54.7%) was the most common available equipment in dental offices. Independent t-test showed a significant relationship between participation in medical emergency courses and the availability of an emergency kit in the dental office (p value = 0.04). The majority of dental offices in our study had incomplete emergency kits and most of the dentists did not have adequate skill in providing emergency services such as IV or SC injections. The results of this study strongly suggest proper practical training both for dentists and students.

Extraction of the upper first premolars and mesial movement of molars result in mandibular counterclockwise rotation and reduced facial vertical dimension. On the other hand, molar extrusion during the orthodontic treatment changes facial vertical dimension. Therefore, it is possible to avoid vertical changes of the face by maintaining the vertical position of posterior teeth. This study was designed to evaluate changes in the vertical dimension of the face in class II div I patients treated by extraction of the upper first premolars. This cross-sectional study was conducted on 20 patients, with a mean age of 17.8 years, who were selected from a private office. The subjects had class II malocclusion and normal vertical growth. To decreasing the effect of growth on the results, we selected subjects >15 years of age. As a part of their orthodontic treatment their upper first premolars had been extracted. The lateral cephalometric radiographs of the patients were digitized. Image analyses were conducted using View box 3.1.1 software program and data was analyzed with SPSS 20. Paired t-test was used to compare each variable before and after treatment (α = 0.05). In this study, there was no statically significant differences in skeletal variables. However, dental variables of U1-NA (mm), U1-NA, U1-FH, and overjet exhibited significant decreases (p value < 0.05). There was no significant differences in lower incisor variables. U6-palatal P, interincisal angle, U 1-palatal P exhibited significant increases. The results of this trial showed that treatment of class II div I through extraction of upper first premolars results in molar extrusion and in a decrease in upper incisor protrusion with no changes in the facial vertical dimension.

The aim of this study was to compare the retention of zirconium oxide ceramic copings at a 24 degree convergence angle with four different types of cement. In this experimental study, 40 first and second premolars were randomly divided into four groups (n = 10). After preparing the specimens, zirconia copings were cemented using RelyX Ultimate, Panavia F, resin-modified GI and zinc phosphate cements under a 5-kg force, followed by thermocycling (3000 rounds 5-55°C) for 24 hours in water with pH = 7 and a temperature of 37°C. Then the copings were separated under a tensile strength in an electromechanical universal testing machine at a strain rate of 0.5 mm/min and their retention was measured. Data were analyzed using SPSS 25 with Kruskal- Wallis and Mann-Whitney tests. The means and standard deviations of retention in the RelyX Ultimate, Panavia F, resin-modified GI and zinc phosphate groups were 7.17 ± 1.13, 4.26 ± 0.37, 2.72 ± 0.43 and 2.3 ± 0.57 MPa, respectively, with significant differences between the groups (p value < 0.001). Based on the results of this study, the retention of ceramic copings of zirconium oxide at a 24-degree convergence angle was different in terms of the cement type, with RelyX Ultimate cement exhibiting the highest retention.

Currently, CBCT is a relatively new oral and dental imaging technique with a variety of capabilities and applications for the diagnosis and follow-up of orodental problems. The use of CBCT in orthodontics has many advantages, basically due to the relative superiority of 3D radiography over the 2D technique. The aim of this study was to evaluate awareness of general dentists and orthodontists in Isfahan about the applications of CBCT in orthodontic therapy in 2017. This descriptive–analytical study was carried out on 104 general dentists and 33 orthodontists working in Isfahan, who were selected using simple random sampling technique. A questionnaire, consisting of 13 questions on the awareness of general dentists and orthodontists in Isfahan about the applications of CBCT in orthodontic therapy, was designed and distributed among them. Based on the total score, dentist’s awareness was categorized as poor, moderate and good. Data were analyzed with SPSS 22, using t-test to compare awareness and years of practice, chi-squared test to analyze the effect of gender and degree (general practitioner or specialist) and Pearson’s correlation coefficient to evaluate the correlation between years of practice and awareness. In addition, two-way ANOVA was used to evaluate the effect of sex and educational degree on awareness. Among 104 general dentists and 33 orthodontists, the mean awareness score of orthodontists was 28.66, classified as a good level of awareness; the general dentists scored a mean of 27.83, classified as moderate level of awareness. There was no significant difference between the two groups of subjects. There was no significant difference in the mean scores of awareness between the two genders. Based on the results of this study, the levels of awareness about applications of CBCT in orthodontic therapy in general dentists and orthodontists were moderate and good, respectively.

Considering the ever-increasing growth of smoking and its various complications, including dental and osseous problems, and considering the importance of bone in the dental implant, it seems research is needed to determine the rate and magnitude of the effects of cigarette smoking on dental implants. Given various reports from various works, the present study was undertaken to evaluate the effect of cigarette smoking on the resorption of the crest of the alveolar bone around implants. In this retrospective cohort study, the patient's data were recorded in two groups, who were cigarette smoker and non-smokers. Twenty-five patients were randomly selected from each group. The subjects underwent panoramic radiographic examinations and the amount of bone loss was determined using the initial panoramic radiograph. Data were analyzed with descriptive statistical methods such as percentages and t-test using SPSS 22 (α = 0.05). TThe majority of the subjects were 40-45 years of age. Data showed no significant difference in the means of changes in the alveolar crest between the two groups (p value = 0.443). In addition, the results showed no significant difference between the mean values of alveolar crest changes between males and females (p value = 0.891). The present study showed that the rate of the alveolar bone crest height in smokers was greater than that in non-smokers; however, the difference was not statistically significant.

Oral cancers are the eighth most common cancers in males and the 15th in females. Squamous cell carcinoma comprises approximately 94% of oral malignancies. Oral cancer develops and progresses during two important biological stages. The aim of the present study was to determine the expression of E-cadherin protein in different stages of oral mucosa SCC after evaluation of the role of this protein in the tumorigenesis of oral mucosa squamous cells. In the present retrospective, descriptive- analytical study, 20 paraffin blocks fixed with formalin, consisting of 10 samples with a diagnosis of well-differentiated oral squamous cell carcinoma (OSCC) and 10 samples with a diagnosis of poorly differentiated OSCC, were selected and stained with immunohistochemistry technique, irrespective of the patient age and gender. In addition, 5 samples of normal oral mucosa were selected as controls. Then the stained samples were evaluated by two pathologists. Data were analyzed with Chi-squared, McNemar and Fisher’s exact tests using SPSS 20 (α = 0.05). The expression of E-cadherin marker exhibited a significant decrease with a decrease in histological differentiation of OSCC at different differentiation levels in terms of location, staining and presence and absence of staining homogeneity of the marker. In addition, the staining of the marker exhibited significant differences between poorly and well-differentiated cells. The results of the present study showed that the expression of E-cadherin protein decreased with poor histological differentiation of squamous cells.

One of the main educational goals in universities is to enhance the quality of education and improve learning among students. The type of resources the students use might have an important role in effective learning and promotion of educational success. The present research was undertaken to investigate the attitudes of dental students in Isfahan University of Medical Sciences toward their sources of study in the 2016‒2017 educational year. In this descriptive/cross-sectional study, a designed questionnaire was distributed among 661 undergraduate students of Dental School of Isfahan University of Medical Sciences in the 2016‒2017 educational year. A total of 512 completed questionnaires were received and finally, 503 questionnaires were analyzed. Data were collected by a researcher-designed questionnaire whose validity and reliability were confirmed and analyzed with SPSS 23, using descriptive and analytical tests such as chi-squared test, ANOVA and Pearson’s correlation coefficient. Statistical significance was set at
p value < 0.05. The results indicated that 429 (85.3%) of the students preferred the lecture notes as their primary source of study throughout the semester. This value, however, increased to 438 (87.1%) during the final exams period. The results also showed a significant correlation between the students’ average grades and the type of material they used as their primary source of study (p value = 0.048). The results showed that most dentistry students use lecture notes as their primary source for studying. Since use of inappropriate sources might limit the students’ knowledge, it is important for dental schools to take appropriate actions to revise educational policies in order to encourage the students to use textbooks in dentistry.

Root canal therapy is one of the most important treatments for oral and dental health. To a large extent, the success of treatment is dependent on endodontic treatment errors, and since the treatment errors are affected by the type of dental education, the aim of this study was to compare the prevalence of errors during root canal treatment by students, entering the university in 2010-2012, who were trained with and without the use of a head phantom in the Faculty of Dentistry, Isfahan University of Medical Sciences. In this descriptive-analytical study (historical cohort), 400 records were collected from the students entering the university in 2010, who were trained without a head phantom, and 400 cases related to students entering the university in 2012, who were trained with a head phantom. The records were first coded by one of the members of the admission department and then examined by two researchers for the root canal errors during the stages of access cavity preparation, root canal preparation and obturation of the root canals. These errors were collected in a double-blind manner and analyzed with SPSS 20, using Chi-squared test. Statistical significance was set at p value < 0.05. In this study, root canal treatments rendered by dental students of Isfahan University of Medical Sciences were proper in 67.5% of the cases and the prevalence of root canal treatment error was 32.5% among students. The highest frequency of root canal errors among students was related to overfilling (43.9%) and the least error was related to furcal perforation (0.37%). The prevalence of root canal treatment errors among students entering the university in 2010 and 2012 were 41.6% and 24.4%, respectively. The present study showed that the prevalence of endodontic treatment errors by students trained with a head phantom was significantly less than that by those who were trained without a head phantom. Therefore, it can be concluded that the teaching of dental students using head phantoms can reduce root canal treatment errors by students.

The aim of orthosurgery treatment is not only to improve the function and esthetic appearance of dentofacial deformities but also to pay attention to patients’ psychological functions. The aim of this study was to evaluate the psychosocial effects of orthognathic treatment and maxillofacial surgeries on candidates for maxillofacial surgeries. In this descriptive‒analytical study, 27 patients who were candidates for orthognathic surgery were selected and assessed by MMPI questionnaire one month before surgery and two months after surgery. Then, the results were compared with a control group consisting of 30 dental students with Angle class I occlusion, who were matched in terms of sex and age. Data were analyzed with t-test, paired t-test and chi-squared test (α = 0.05). Schizophrenia, psychasthenia, paranoia and depression scores in the test group were significantly higher than those in the control group before the surgery (p value < 0.05). However, there were no significant differences in other psychosocial profiles between the test and control groups before surgery. The mean depression score was significantly higher in the test group compared to the control group after surgery (p value < 0.04); however, other psychological profiles were not significant different between the two groups. The mean schizophrenia and psychasthenia scores decreased significantly after surgery (p value < 0.05), with no significant differences in other psychological aspects. Maxillofacial deformities might result in some psychological disorders in patients and orthognathic surgery might help decrease some of these disorders.

IIt is important to have proper knowledge about the blood supply of the maxillary sinus to prevent unnecessary complications during surgeries. The aim of the present study was to evaluate the posterior superior alveolar artery (PSAA) in subjects > 20 years of age using the CBCT technique. In this descriptive ‒ analytical study, CBCT scans of 135 patients, with a mean age of 34.4 years, were analyzed. The diameter, the distance to the medial wall of the sinus and the position of the artery within the sinus wall were evaluated on coronal sections. Data extracted from the SIDEXIS 3D software program were analyzed with SPSS 20, using independent T-test, Chi-squared test and one-way ANOVA (p value < 0.05). In 243 (90%) patients, PSAA was detected within the maxillary sinus, with no significant difference in distribution of the artery between females and males (p value = 0.33). The most and least frequent locations of the artery were in the first molar and the first premolar areas, respectively. The most common type of artery was intraosseous (type I). The maximum and minimum mean distances between the artery and the medial wall of the artery were found in the third molar and the first premolar areas, respectively. In addition, the mean distance between the artery and the medial wall and the mean vertical diameter decreased with aging (p value 0.001). CBCT can provide useful information about the anatomic structures inherent to the maxillary sinus and PSAA to prevent unnecessary complications during surgery.

Studies on occupational hazards indicate that a large number of dental surgeons are at risk of developing various types of musculoskeletal disorders caused by this profession. Since dentists play an important role in improving the health of the community, musculoskeletal problems in these individuals reduces the duration of useful services by these health practitioners. The aim of this study was to determine the prevalence of musculoskeletal disorders among general dental practitioners
in Isfahan. A total of 278 general dental practitioners in Isfahan participated in this descriptive cross-sectional study. A standard Nordic questionnaire was used to collect data which were analyzed with SPSS 21 using chi-squared test and t-test (α = 0.05). According to the results of this study, 95.7% of dental surgeons had musculoskeletal disorders in one or more regions of the nine regions of the body. Only 4.3% of dentists did not report any disorders. The percentages of musculoskeletal disorders in dentists in terms of the region affected was as follows: neck, 78.1%; shoulder, 57.2%; waist, 56.8%; hand and wrist, 52.9%; upper back region, 52.2%; knees, 34.5%; elbows, 17.3%; pelvis and thighs, 16.9%, and legs and ankles, 15.8%. The results of this study showed that musculoskeletal disorders in general dentists in Isfahan is very prevalent and intervention and corrective measures are necessary.

Antibacterial agents are required for endodontic surgery. The aim of this study was to compare the antibacterial activities of two new root-end filling materials and MTA against Enterococcus faecalis. This in vitro study was carried out using direct contact test (DCT). The materials studied consisted of a calcium aluminate-based cement (CAAC, calcium aluminate α-aluminate cement) and a calcium silicate-based cement which was a mixture of wollastonite, CAAC (WOLCA) and MTA. Each cement was prepared immediately after mixing (not set), 3 days and 1 week after their setting and placed at the bottom of 4 wells from a 96-well plate (group A). Approximately 10 μL of Enterococcus faecalis suspension at 0.5 McFarland concentration and 245 μL of BHI were added to the wells in group A and empty wells in group B. Finally, the growth rate of bacteria in the wells in each group was monitored every 30 minutes for 7 hours and once after 24 hours using the spectrophotometry technique. Data were analyzed with ANOVA for repeated data and with one-way ANOVA and post hoc Tukey tests (p value = 0.05). Tukey tests showed a significant difference between the freshly mixed MTA and the MTA one week after its setting (p value = 0.033). In addition, there were significant differences between MTA one week after its setting and CAAC one week after its setting and between MTA one week after its setting and WOLCA three days after its setting (p value = 0.039 and p value = 0.043, respectively); however, there were no significant differences between the other groups. Due to the similarity of the antibacterial activities of the tested cements and MTA and even higher antibacterial activities of CAAC one week after its setting, and WOLCA three days after its setting compared to MTA one week after its setting, these cements can be considered for further in vitro and clinical studies in future.