Journal of Dental Medicine

Statement of Problem: The Prevalence of HBsAg, among patients with Down Syndrome (DS) has been reported higher than normal population. Living in institutes, comparing to home, leads to higher probability of HBsAg prevalence.

Aim: The purpose of the present study was to determine HBsAg prevalence in patients with DS and compare it with other mentally retarded patients with similar conditions, and also with healthy population in Iran.
Materials and Methods: One hundred patients, with average age of 12 years, living in five institutes inTehran, were chosen. Children with DS and other mentally retarded children were considered as the first and second groups, respectively (50 members in each group). Blood samples were taken and tested (ELLSA) to determine HBsAg and HBsAb titre. For statistical analysis, Chi- Square test was used.

Results: HBsAg was positive in 8% and 4% of DS and MR groups, respectively. HBsAb was seen in 25% of DS, comparing to 32% of MR. The prevalence of HBsAg in retarded patients living in institutes was higher than normal population of Iran (less than 3%), which was not statistically significant.
Conclusion: Consideration of sterilization principles and infection control upon dental operations, in these centers, are necessary. It is also suggested that these children, as a high- risk population, should be vaccinated against hepatitis B.

Background and Aim: Giant cell granuloma is a relatively common benign proliferative lesion of the oral cavity. This lesion has a marked gender predilection with more prevalence in females and tendency to rapid growth and recurrence during pregnancy. The aim of this study was the evaluation of specific receptors of sex hormones in giant cell granuloma.

Materials and Methods: In this cross-sectional study, twenty five cases of formalin fixed paraffin embedded giant cell granulomas were retrieved from the oral pathology archive of dental school Isfahan University of Medical Sciences. Also twenty five normal oral mucosa biopsies resected during different surgical procedures were prepared as control group. Cases were immunohistochemically stained for estrogen and progesterone receptors using the biotin-streptavidine method. Data were analyzed by SPSS package.

Results: Staining for ER/PR markers were negative for the mononuclear stromal cells and multinucleated giant cells in all cases. The epithelial cells and connective tissue stromal cells of the control group were also negative for these receptors.

Conclusion: Based on the results of this study, immunostaining for ER/PR was negative in all cases. These findings suggest that in most cases development and growth of this lesion is not directly related to these hormones. However further studies with more sensitive techniques are recommended.

Background and Aim: Extensive and continuous consumption of acidic drinks is the main cause of enamel erosion in human teeth. The purpose of this study was to compare the erosive potential of two Iranian drinks with those of two imported ones.

Materials and Methods: Two Iranian drinks (Cola Zamzam and Orange Zamzam) and two imported ones (Pepsi and Miranda) were studied in this experimental invitro study. 120 intact premolar teeth, extracted for orthodontic reasons were divided into 3 equal groups (A, B and C). Each group was exposed to one of the drinks for exposure times of: A: 15 minutes, B: 45 minutes and C: 12 hours. Each group was divided into 4 subgroups (each containing 10 teeth), which were exposed to 20 ml of one of the 4 drinks. The exposed surface was the same in all samples (a 5 mm in diameter semi circular window). The amount of Ca++ ion (mg/ml) added to each drink at the end of exposure time was estimated by atomic absorption spectrophotometer.

Results: 2 way ANOVA showed that the drinks were significantly different with regard to released Calcium ion. Time had significant effect on erosive potential. The two mentioned factors had significant interaction (P<0.001). The most erosive effect was seen in 12 hours in all of the drinks. The erosive effect of Orange Zamzam in 15 minutes and Pepsi in 45 minutes and 12 hours was significantly more than other groups (P<0.001).

Conclusions: Pepsi had the most long term erosive effect among the four drinks, and Cola Zamzam had the least erosive potential.

Background and Aims: Working length determination and remaining this length is of great importance in root canal therapy. Recently, electronic apex locators are being used to determine working length and decrease the number of radiographs. The purpose of this study was to compare the sensitivity of Root ZX and Novapex electronic apex locators with radiography in a clinical study.

Materials and Methods: In this study, 73 single-canalled teeth of the patients referred to the endodontic department of the Yazd Dental School were evaluated. The access cavity was prepared and working length of the root canals were measured by using the apex locators: Root ZX and Novapex. The file was placed in the root canal and a periapical radiograph was taken using parallel technique. The working lengths obtained by apex locators were recorded and compared with those of radiographs. The data were analyzed by Pearson's correlation coefficient, Wilcoxon test and paired t-test.

Results: The exact measurement without any fault was 46.6% for Root ZX and 20.5% for Novapex compared to radiography. In the range of 0.5 mm fault, the results were 91.8% for Root ZX and 64.4% for Novapex compared to radiographic measurements. The difference between the average of the measured lengths by Root ZX and radiography was not significant (P=0.17). On the other hand, the results showed significant difference between the average of the measured lengths by Novapex and radiography (P=0.017). The difference between two apex locators was not significant (P=0.061).

Conclusion: Root ZX and Novapex with high accuracy are useful for determining working length of the root canals in pregnant patients with special anatomic conditions and patients with muscle disharmony. Therefore, the use of these apex locators combined with radiography is recommended in root canal treatment.

  Background and Aims : Dentists have usually a critical role in diagnosing oral cancer lesions in their early stages. In this study we aimed to assess the senior dental student’ and dentists’ knowledge, attitude and behaviors regarding oral cancer in Isfahan.

  Materials and Methods: A valid and reliable self-administered questionnaire was designed to assess the current practice, knowledge and attitude of general dentists working in Isfahan-Iran and senior dental students regarding oral cancer lesions. The questionnaire was consisted of questions to assess the knowledge and attitude regarding diagnosis, risk factors and prognosis of oropharyngeal cancerous lesions. The frequencies of answers to questions in sections of practice and attitude (just for dentists) and sum score of questions in knowledge section were calculated and compared using statistical analysis regarding age, sex, duration of experience and practice setting ) p ublic/private) of participants. Data were analyzed using ANOVA, chi-square, linear regression and logistic regression.

  Results: 139 questionnaires from dentists and 57 questionnaires from students were returned. The mean score of dentists’ knowledge was 5.41 out of 13 (CI95%=5.03-7.79 ). Significant differences were observed among dentists regarding their experience (P=0.001). Only one fifth of the dentists in our survey reported to perform oral cancer examination for all of their patients in age of 40 and above and just about 34% of dentists gained acceptable level of knowledge. Among senior dental students, the status of knowledge was better as about 58% of them gained the level of acceptance (P=0.01).

  Conclusion: Although dentists were willing to follow the diagnostic protocol for oral cancer, they were mostly unsatisfied with the level of their knowledge. Therefore, this study highlights the need for educational planning and training activities in general dentists with regard to the risk factors and early detection of oral cancers.

  Background and Aims Bone density is frequently used in medical diagnosis and research. The current methods for determining bone density are expensive and not easily available in dental clinics. The aim of this study was to design and evaluate the accuracy of a digital method for hard tissue densitometry which could be applied on personal computers.

  Materials and Methods: An aluminum step wedge was constructed. 50 E-speed Kodak films were exposed. Exposure time varied from 0.05s to 0.5 s with 0.05 s interval. Films were developed with automatic developer and fixer and digitized with 1240U photo Epson scanner. Images were cropped at 10 × 10mm size with Microsoft Office Picture Manager. By running the algorithm designed in MATLAB software, the mean pixel value of pictures was calculated.

  Results: Finding of this study showed that by increasing the exposure time, the mean pixel value was decreased and at step 12, a significant discrimination was seen between the two subsequent times(P<0.001). By increasing the thickness of object, algorithm could define the density changes from step 4 in 0.3 s and 5 in 0.5 s, and it could determine the differences in the mean pixel value between the same steps of 0.3 s and 0.5 s from step 4.

  Conclusion: By increasing the object thickness and exposure time, the accuracy of the algorithm for recognizing changes in density was increased. This software was able to determine the radiographic density changes of aluminum step wedge with at least 4mm thickness at exposure time of 0.3 s and 5 mm at 0.5 s.

Background and Aims: Type 1 diabetes mellitus, is the most common metabolic disorders in children and adolescents. The aim of this study was to assess the state of oral health in children with type 1 diabetes compared with healthy children in 2013-2014 in Hamadan province, Iran.

Materials and Methods: The specimens were selected through convenience sampling in two groups. Group one consisted of 80 individuals (5-18 years old; case group), suffering from type 1 diabetes mellitus referred to the Pediatric endocrine clinic. Control group consisted of 80 non-diabetic healthy children who were out- patients of pediatric and orthodontic department of Hamadan dental school. Two groups were similar in age and sex. The data were collected through a questionnaire, medical records and clinical examination. DMFT, dmft, GI and PI indices were assessed in each patient. Data were analyzed using ANOVA and T-test.

Results: In spite of similarity in oral hygiene habits in both group, there was no significant difference in mean DMFT and permanent decayed teeth in both groups (P>0.05), but the mean dmft (P<0.008) and primary decayed teeth (P<0.011) in the control group was significantly higher than that of the case group. Also, diabetic patients had significantly more gingival inflammation (P<0.05). The mean PI in the two groups did not differ significantly. Oral hygiene habits were similar in both groups but diabetic patients were significantly referred to dentists with lower frequency then that of control group (P=0.00).

Conclusion: The devastating effects of diabetes on the oral health, along with other side effects can be effective in promoting tooth decay and gingivitis in diabetic patients. Unfortunately, oral health care and programmed dental visit were not the priority for the diabetic patient (and parents) involved in our study. Therefore, programs to increase awareness and encourage patients for a better control of their oral health in order to diminish diabetes' devastating effects is recommended.