Journal of Mashhad Dental School
Year:2009 | Volume:32 | Issue:4 (67)|Papers Count:13

Introduction: Use of information technology and internet provides the professors and students with the possibility to access the scientific information very quickly. This issue, especially for researchers in developing countries, is useful as internet resolves lack of information in these countries. The objective of this study was to investigate skill and use of information technology and internet among dental professors and students in Mashhad dental school.Materials & Methods: In this descriptive study which was done in 2008, a questionnaire was given to all professors, postgraduate and undergraduate students of Mashhad dental school that contained questions in regard to the quantity of skill and use of computer and internet.Results: The rate of access to computer at home and university among professors, postgraduate and undergraduate students was 83.3%, 53.5% and 33%, respectively. 47.3% of professors reported that they were beginners in the field of IT. This was 76.7% for postgraduate and 61.9% for undergraduate students. The majority of professors (95.9%) and most of undergraduate students (74.2%) and postgraduate students (74.4%) had email. 41.2% of undergraduate students were not familiar with medical information banks. This was less among professors (13.5%) and postgraduate students (11.6%). Conclusion: The rate of access to computer at home and skill rate of professors and students of Mashhad dental school were higher than other studies.

Introduction: The success rate of endodontic treatment is dependent upon many factors among which is fitness of residual apical gutta-percha and post. The purpose of this in vitro study was to determine the effect of the distance between the post and the residual gutta-percha on canal microleakage.Materials & Methods: In this experimental study, a total of 72 human central maxillary teeth with same size roots were selected. The process of root canal obturation, post space preparation and post cementation was the same for all the teeth.The teeth were divided randomly into three groups of 1-no gap between the gutta-percha and the post, 2-gap of>0 to 2 mm and 3-gap of>2 mm. Posts were cemented by Glass Ionomer and the leakage was determined by dye method. Samples were cut longitudinally and were then observed under the microscope. The results were analyzed by Chi-square tests.Results: There was a significant difference in microleakage between the studied groups. The highest leakage of total surfaces was seen in group with space more than 2 mm between the residual gutta-percha and the post, and the least microleakage was seen in group without any space. The results were singnificant (P<0.001).Conclusion: When the space between post and gutta-percha increases or decreases, the leakage will increase or decrease as well. However, by decreasing this space to zero, the leakage will never be none.

Introduction: Periodontal disease is a common infection-induced inflammatory disease among individuals suffering from diabetes mellitus. The aim of the present study was to investigate the effect of non surgical periodontal therapy on HbA1c value in type 2 diabetes mellitus patients.Materials & Methods: In this clinical trial study, approved by ethical committee of Tehran Shahed University of Medical Sciences, 20 patients with poorly controlled type 2 diabetes mellitus and chronic periodontitis were selected from Yazd diabetes center and received mechanical periodontal treatment (oral hygiene instruction, full mouth scaling and root planing). At base line and after 3 months, the glycated hemoglobin values (HbA1c), fasting blood sugar and clinical periodontal parameters (plaque index, gingival index, probing depth, percent of sites with probing depth³4 mm, and percent of sites with probing depth³6 mm were recorded. Paired t-test was used for data analysis.Results: After treatment, all patients showed clinical improvement in periodontal status (P<0.001). The HbA1c value reduced significantly after the 3 months of observation period (P<0.001).Conclusion: The results of our study showed that non surgical periodontal treatment is associated with reduction in glycated hemoglobin level in type 2 diabetic patients. Control of periodontal infection as an important part of the overall management of diabetes mellitus patients, is recommended.

Introduction: Shortage of bone, especially in sagittal dimension, is of great importance in preventing proper positioning of dental implants. The aim of this study was clinical evaluation of interpositional technique using the mixture of Bio-oss and autogenous bone.Materials & Methods: In this clinical trial study, four Patients took part in the present study who had reduced width of ridges. Augmentation surgery was performed under local anesthesia as follows: A horizontal incision was performed on soft tissue slightly lingual to the crest of edentulous ridge. A mucoperiosteal flap was elevated. A horizontal cut was made along the crest of bone and two vertical bony cuts were done at buccal side of the ridge. A green stick fracture was created at base of the buccal plate using a surgical chisel and buccal plate was mobilized gradually to create a furrow between buccal and lingual plates. This space was filled with a graft material consisted of the mixture of Bio-oss and autogenous bone harvested from symphysis. Then and the flap and tension free edges of flap were sutured. Six month later, the study cast was prepared and all measurements were repeated and results were analyzed statistically by paired t-test.Results: The mean ridge width increase was 3.56±0.78 mm and the width of ridge significantly differed after augmentation (P=0.001). Mean vertical bone loss was 0.75±0.93 mm and the reduction was not statistically significant (P=0.056).Conclusion: This study demonstrated that interpositional technique using the mixture of Bio-oss and autogenous bone was a valuable technique for lateral ridge augmentation.

Introduction: Recording the maxillomandibular relation is one of the important procedures in prosthodontic treatments. The centric relation (CR) of occlusion is the most important of these records. Body posture of the patient is one of the factors influencing the CR. In this study, we investigated the influence of patient's body position in CR recording by extra-oral tracing method.Materials & Methods: In this cross-sectional study, 18 edentulous Patients were randomly selected. After patient education, the extra-oral tracing device was attached to patient's dentures. Then the Gothic arch tracing was accomplished in supine, semi supine and upright position. The CR achieved by bimanual manipulation method was also recorded. Then the horizontal, anterior-posterior and straight distances of each point to point achieved by Dawson method, were calculated. Data were statistically analyzed using the one-way ANOVA and t-test. The level of significance was set at 95%.Results: In edentulous subjects, there was no significant difference between horizontal distances of points registered in various body positions and the point registered in Dawson method, but with a view to ant-post and direct distances, the points registered in supine position were significantly nearer to that of Dawson method rather than the points registered in upright position.Conclusion: In edentulous subjects, and in comparison to upright position, the CR obtained in supine position by extraoral tracing method, was significantly similar to bimanual manipulation.

Introduction: The aim of this survey was immunohistochemical evaluation of MIB-1 expression in dental follicle and dentigerous cyst regarding to the capability of neoplastic changes and ability for more proliferation and more recurrence after enucleation in dentigerous cysts.Materials & Methods: Sections taken from paraffined block of 12 cases of dentigerous cyst and 12 cases of dental follicle were stained with MIB-1antibody, using immunohistochemical method. The observing of all of the stained sections was done according to Hscore gradation and a degree of staining intensity of epithelial cells and the percent of stained epithelial cells were considered. Then the aggregate these two were announced as the final score. The data were analyzed by Mann-Whitney test.Results: The expression of MIB-1 in dentigerous cyst was greater than dental follicle (P<0.001). This difference was significant for the percentage of stained epithelial cells (P=0.001) and it was greater in dentigerous cyst.Conclusion: The expression of MIB-1 in dentigerous cyst was greater than dental follicle. This difference may are attributed to the capability of neoplastic changes and ability of proliferation in epithelium layer of dentigerous cyst and different clinical behavior of dentigerous cyst.

Introduction: The epulis fissuratum is a reactive inflammatory lesion associated with the periphery of ill-fitting dentures that histologically resembles the fibroma. For treatment of them, blade surgery, electrosurgery and cryosurgery and laser can be used. No need for sutures, preserving depth of vestibule and no or little bleeding are benefit of electrosurgery and cryosurgery over blade surgery. This study was done for comparing electrosurgery and cryosurgery for removing these lesions.Materials & Methods: In this clinical trial study, approved by ethical committee of Isfahan University of Medical Sciences, 20 lesions of epulis fissuratum with about 1cm size was randomly divided into two similar groups for removing by electrosurgery and cryosurgery. Healing time and pain after surgery were compared between the two groups. Survival analysis, t-test and repeated measure ANOVA were used for data analysis.Results: Healing time in cryosurgery was 14.5 days and in electrosurgery was 12.8 days. Survival analysis about clinical healing period showed a significant difference between the two methods (P=0.0216). Pain intensity was not significantly different between the two methods.Conclusion: Clinical healing period in electrosurgery was shorter than cryosurgery. Since, cryosurgery was done without anesthetic injection and had no unpleasant smell, it should be considered for some patients.

Introduction: Apical root resorption of maxillary incisors is relatively a common phenomenon at the end of orthodontic treatment. Therefore; recognizing risk factors in root resorption before starting the treatment is very important for prevention and reduction of complications. The aim of this study was to compare the amounts of apical root resorption in different vertical malocclusion groups before and after fixed orthodontic treatment.Materials & Methods: In this cross sectional study, the amount of apical root resorption in maxillary incisors in 100 patients (13-18 years old) with class I malocclusion (37 normal bite, 35 deep bite, 28 open bite) were measured through the examination of parallel radiographies (long cone) before and after treatment using photoshop program (software 7.0). Then the groups were compared and analyzed by t-test, One Way ANOVA, Mann-Whitney and Tukey tests.Results: The amount of apical root resorption at central incisors in deep bite groups was significantly greater than normal bite groups (P=0.008) and in normal bite groups insignificantly greater than open bite groups (P=0.013). The amount of apical root resorption at lateral incisors in deep bite groups was significantly greater than open bite groups (P=0.004) and in open bite groups was significantly greater than normal bite groups (P=0.006).Conclusion: The comparison of apical root resorption between deep bite, normal bite and open bite groups indicated that the resorption in deep bite group, in both central and lateral incisors, was more than the other groups.

Introduction: Medical emergencies could occur in the practice of dentistry. A dentist must be prepared to assist in recognition and management of any potential emergency situation. The purpose of this study was to determine the prevalence of medical emergencies in the dental offices and to evaluate 'Knowledge' and 'Attitude' of dentists upon encountering these situations.Materials & Methods: This descriptive, cross-sectional study was performed on 64 general dental practitioners in 2005 using a questionnaire. The questionnaire had been prepared based on valid references. The data were analysed & compared using Pearson correlation test through SPSS software.Results: Results showed 67.7% of the study group were men and 32.3% were women. The mean age of the study group and duration after graduation time were 31.6 and 4.9 years respectively. 96.7% of the dentists filled out the questionnaire. 61% of the dentists achieved positive scores in attitude and 96.8% got moderate to good scores in knowledge. There was no significant relationship between age and duration after graduation time, and knowledge (r=0.08, P=0.53). The most frequently reported emergency was orthostatic hypotension.Conclusion: Medical emergencies occur in dental offices frequently. There is a perceived need for further related practical training among dental practitioners.

Introduction: Assessing oral health in children plays an important role in determining the health status and health promotion programs of communities. This survey was carried out to study dental caries experience of preschool children in Birjand and factors affecting their caries stata.Materials & Methods: In this analytical-descriptive study, approved by ethical committee of Mashhad University of Medical Sciences, 434 children aged 13-72 months were randomly selected from kindergartens in the city of Birjand and examined for dental caries using WHO criteria. A questionnaire concerning Socio- economic background was filled by their parents. Data analysis was performed using the software SPSS, Mann-Whitney, Chi-Square, Kruskull Wallis and Logistic Regression tests were used. The level of statistical significance for all tests was set at P<0.05.Results: The overall mean dmft score in children of the study was 4.99±4.11 and dmfs was 7.88±8.45. The prevalence of caries free children was 16.1% and early childhood caries (ECC) and severe early childhood caries (SECC) were 83.7% and 50.2% prevalent respectively. There was a decrease in the proportion of caries free children with an increase in age (P<0.001). The children whose parents (especially mother) had attained a higher education level had lower dmft scores. The children whose mothers were occupied had lower dmft scores (P<0.001).Conclusion: Our results indicate the high caries prevalence in children in Birjand and parent's educational level as a contributing factor. Therefore there is a need for educational programs to prevent caries especially for children from lower socio-economic classes.

Introduction: Langerhans Cell Disease (LCD), formerly known as Histiocytosis X, is a rare disorder characterized by a proliferation of cells exhibiting phenotypic characteristics of langerhans cells. The etiology and pathogenesis of this disease is unknown. The disease is categorized according to the extent of involved organs. Oral manifestations may be the first and the only sign of the disease. A number of signs can be clinically observed such as periodontal involvement, oral ulcers, gingival bleeding, mobility and premature exfoliation of the teeth or gingival enlargement. In this paper, a case of langerhans cell disease with oral manifestations has been presented.Results: A 6-year old boy was referred with a chief complaint of progressive luxation of posterior teeth. Intraoral examination revealed gingival enlargement with teeth loosening in posterior areas of the jaws. Our clinical diagnosis was Langerhans cell disease. In panoramic radiography, multiple well-defined radiolucencies were observed in both maxilla and mandible. Skull X-ray was normal. Histopathologic examination and S100 protein staining confirmed our diagnosis. The patient was referred to pediatric oncologist and underwent chemotherapy. In follow up examinations we noticed regression of gingival lesions. Chemotherapy was stopped after one year of treatment.Conclusion: Since early diagnosis and treatment of this disease is important in the prognosis, dentists should be aware of oral manifestations and differential diagnosis of this disease. In patients in whom the only manifestation of LCD is oral involvement, early diagnosis and referring of the patient by dental practitioners for proper management is very important.

Introduction: Odontoma is the most common odontogenic, non cystic lesion of the jaw. Surgical enucleation is the treatment of this lesion, which often in more extensive lesions, the operation is performed under general anesthesia. The purpose of this report was to assess the possibility of surgery for major lesions under local anesthesia.Results: Recommended patients were 3 women and 2 men with age range of 20-35 years with extensive mandibular odontoma. All surgeries were performed under local anesthesia in oral & maxillofacial surgery department of Mashhad dental school.Conclusion: All the patients were satisfied with ambulatory treatment and the performance of surgery under local anesthesia. They passed postoperative latent period (almost 7 days), and revealed no surgery complications.