Journal of Mashhad Dental School
Year:2013 | Volume:36 | Issue:4 (83)|Papers Count:13

Introduction: Considering to patient’s complications with conventional denture in the lower arch, the requirement of a denture with more efficacy and cheaper than conventional ones, is definite. One of the most conventional ones is an overdenture with 2 implant. The purpose of this study was comparison of four types of different attachment systems including two prefabricated and 2 castable attachments.Materials & Methods: Four groups with 6 numbers of attachments (Superflex ball, locator, castable Ball on bar, castable Bar) were selected. 2 castable groups were casted; these attachments were put on implant fixtures. Then a Cr-Co framework was made. It was put on cast and attachments and an acrylic base was made on this assembly. All the samples were put in universal testing machine and a tension force of 50 Newton was loaded to seprate framework from cast. The tension force was recorded. After data collection, the data were analyzed through SPSS version 16 by One-Way ANOVA and Teukey test.Results: Results showed that retention force of castable ball on bar (35. 31N) was the greatest followed by ball (33.33N, P=0.007), Locator (20.90N) and castable bar (14.74N), respectively (P<0.001).Conclusion: Castable ball on bar was comparable to ball regarding the retentive force. Therefore this cheap attachment could be used in patients instead of prefabricated one. These attachments have more retention compared to locators which are expensive. When less retention is needed, castable bar can be used, and when more retention is needed, castable ball on bar is recommended.

Introduction: Human teeth are valuable indicators of the capacity of metals in the body. The purpose of this study was to determine the concentration of zinc and copper in different teeth types in 5-12 year old children population living in the city of Birjand.Materials & Methods: Teeth samples were collected from dental clinics and prepared for analysis using acid digestion. Samples were analyzed for Zn and Cu concentrations by flame atomic absorption spectrophotometry. Kolmogorov Smirnov was used for normal data, One Way ANOVA was used for comparison among teeth groups and t-test for comparison between sexes (P<0.05).Results: Based on the results of this study, the mean concentrations of copper and zinc in tooth samples were 8.44±4.22 mg/kg and 218.14±94.81 mg/kg, respectively. The results also showed that copper levels were significantly higher in the teeth of boys compared to that of girls, while a significant difference in zinc level between the teeth of the boys and girls was not found. The concentrations of copper and zinc were statistically different depending on the type of teeth.Conclusion: The results of this study showed that teeth are valuable bio- indicators. All samples had a zinc concentration up 90 mg/kg, indicating that children consumed sufficient zinc. Also, incisor teeth had the highest content of copper compared to the other teeth.

Introduction: Periodontal disease is a chronic bacterial infection that affects the tissues supporting the teeth. Our effort in improving periodontal disease is to reduce destructive mediators. One of the Biomarkers is osteoprotegrin (OPG). OPG is a protein which prevents osteoclast activity. The aim of this study was evaluationof osteoprotegrin (OPG) concentration in saliva of patients with generalized moderate chronic periodontitis and comparing it with that of healthy individuals.Materials & Methods: This study was carried out on 30 patients (15 patients with chronic periodontitis and 15 patients as the control group) referred to Ahvaz Jundishapour dental school. Saliva samples were collected and examined by ELISA. The data were analyzed by t-test.Results: Mean OPG coucentration in patients and control group were 117.63±84.13 mg/dl and 210.81±170.69 mg/dl respectively. The difference was not significant.Conclusion: It appears that OPG concentration in saliva cannot be used as a marker for the assessment of periodontal disease.

Introduction: Despite decades of research, there is not a consensus on whether patients with osteoporosis/ osteopenia are at higher risk for jaw bone resorption, periodontitis and tooth loss or not. The purpose of this study was to compare alveolar bone resorption and the number of remaining teeth between postmenopausal women with normal bone mass and postmenopausal women with low bone mass.Materials & Methods: A total of 100 volunteer women, aged from 40 to 70, who presented at Shiraz Namazi Hospital for the diagnosis of osteoporosis were selected and divided into normal and osteoporotic/osteopenic groups. Parallel periapical radiographs were taken from first and second mandibular molars on both sides using radiology device Planmeca Intra Dentsply Rinn=0.32 (KVP=60 MA=8), Ekta speed Kodak film and were digitalized using scaner (Microtek Scanmaker I 800). Values of alveolar bone resorption were determined by measuring the distance between CEJ and the lowest point of the crest in mesial and distal areas of the mandibular first and second molars and central incisor, using the software AutoCAD (2007) with an accuracy of 0.00 mm. Panoramic radiographs were used to evaluate the number of missing teeth. To evaluate bone resorption and to compare the number of the missing teeth, t-test and Mann Whitney test were used respectively.Result: Alveolar bone resorption and the number of the remaining teeth in the postmenopausal women with or without normal bone mass in the studied groups were not different significantly.Conclusion: In this study, no relation was found between the number of the missing teeth/alveolar bone resorption and bone mass in postmenopausal women.

Introduction: Panoramic radiography is used extensively in the field of dentistry as a screening method. In endodontic treatment, the diagnosis and evaluation of periapical area is very important. However, using advanced imaging such as cone beam computed tomography (CBCT) has increased diagnostic ability, but it must be used precisely and in special condition. The aim of this study was to compare diagnostic value of digital panoramic view and CBCT in diagnosis of apical lucent lesion.Materials & Methods: In this cross-sectional study, digital panoramic view and CBCT of 47 patients (573 apical portions of root) who had referred to maxillofacial radiology clinic for maxillary and or mandibular CBCT procedures were assessed. All of the selected patients needed these images as their treatment protocol. According to order of CBCT (maxilla, mandible and both), the teeth of the same jaw in digital panoramic radiography by a maxillofacial radiologist were evaluated. After data enterance, agreement, Sensitivity, specificity and likelihood ratio (positive and negative) were assessed totally and for each jaw separately with 95 percent confidence interval. 0.05 was established as a level of significant.Results: Periapical radiolucency in 15.9% of apical areas in CBCT and in digital panoramic view in 4.2% of them was detected. Overall, sensitivity and specificity of digital panoramic view were 26.4% and 100% respectively. Sensitivity of panoramic view in diagnosis of periapical lucency in mandible was higher than maxilla. According to kappa analysis, the agreement level between panoramic and CBCT was assigned low (kappa=0.374).Conclusion: Although panoramic is a routine screening method in field of dentistry, it is not accurate in diagnosis of the presence of periapical lesions. This limitation in maxilla is more than mandible.

Introduction: Mouth rinses beside the other methods have an important role in reducing dental caries. The aim of this study was in-vitro comparison of the anti-caries effect of polyphenol extract of green tea with 0.05% fluoride, 0.2% cholorhexidine and fluoride-cholorhexidine.Materials & Methods: In this laboratory experimental study, 50 maxillary premolars were placed separately in tubes which contained cariogenic solution (streptococcus mutans, lactobacillus and 3 ml sucrose solution of 20%). Each tube regarding the rinse solution was placed in 5 experimental groups (n=10) as follows: 1) normal saline, 2) 10% solution of green tea polyphenol extract, 3) 0.05% fluoride, 4) 0.2% cholorhexidine and 5) fluoride_cholorhexidine. Every 24 hours, the teeth were rinsed with 5 mL of the rinse. After 21 hours, the depth of decay was measured by polarized light microscope. Data were analyzed by SPSS V 13.0 software using Colmogrove Smirnove, One way ANOVA and Tukey tests.Results: The mean and standard deviation of the depth of the caries in group 1 to 5 were 194±16.43, 175±17.94, 142±9.34, 155±13.27, and 144±8.57, respectively. One way ANOVA showed that there were significant differences between the groups (P<0.001). Tukey test showed that although there was no significant difference in the depth of the caries between groups 1 and 2 (P=0.205), it was significantly less than groups 3 to 5 (P<0.001). There were no significant differences between the depth of the caries in group 3, 4 and 5.Conclusion: According to the results of the current study, the anti-caries effect of flouride_cholorhexidine was the greatest between the groups. As the anti cariogenic effect of green tea was similar to that of normal saline and significantly less than fluoride or chlorhexidine, its use as a common mouth rinse needs more research.

Introduction: Many mucocutaneous lesions of the oral cavity have similar clinical features and therefore the histpathologic findings are very important in correct diagnosis and differential diagnosis of each lesion. The aim of this study was to assess the agreement between clinical and histopathologic diagnoses in mucocutaneous lesions of the oral cavity during 30 years (1979-2009) in Mashhad dental School.Materials & Methods: In this retrospective study, a total of 334 patients with mucocutaneus lesions were analyzed in Mashhad dental school from 1979 to 2009. Patient’s data including age, gender, location, clinical diagnosis and histopathologic diagnosis were recorded. Data were analyzed through SPSS 11.5 Software.Results: In this study, there was an agreement between clinical and histopathologic diagnoses in 295 subjects (77.5%) with oral mucocutaneus lesions. All subjects with pemphigoid and white spongy nevus showed total agreement between clinical and histopathologic diagnoses. Atrophic and pigmenteted lichen planus also showed the highest percentage of agreement in lichen planus groups.Conclusion: In mucocutaneous lesions, clinical, radiographic, and histopathologic findings are necessary for definitive diagnosis of mucocutaneous lesions.

Introduction: With advances in medicine, more systemic patients seek dental treatment. On the other hand, oral health care is an essential part of pregnancy and diabetes mellitus health care. The aim of this study was to assess dentist’s awareness about dental management of pregnant and diabetic patients.Materials & Methods: This study was conducted on 106 out of 204 dentists attending in oral medicine congresses and continuous education programs from June 2009 to June 2010. A self-established questionnaire with approved validity and reliability was used. Along with demographic data, some multiple choice questions about dental management of diabetic and pregnant patients were asked. Totally 20 points were assigned to questions and awareness was classified to excellent (18-20 points), good (14-<18 points), moderate (10-<14 points) and poor (<10 points). Statistical analysis was done by Mann-Whitney and Kruskal-Wallis tests. P-value less than 0.05 were considered significant.Results: The mean awareness score (MAS) was moderate (10.5±2.5). The MAS for pregnancy was (3.5±1.78) of 10 and for diabetes mellitus were (7±1.32) of 10. MAS were higher in women especially about diabetes mellitus but it was not significantly different. The University of Graduation and years of career were not significantly related to awareness status. Education and treatment attitude for pregnant patients were not related to awareness but women had a higher attitude in treatment of pregnant patients (P<0.05). The lowest awareness was about indications of consultation in diabetic patients and the highest awareness was about administration of suitable antibiotic and analgesic during pregnancy.Conclusion: The awareness level of dentists studied here was moderate and low about dental management in pregnancy and diabetes mellitus which should be improved via continuous education programs.

Introduction: Probiotics have been associated to various benefits on oral health, partially through regulation of local immunity. The purpose of this study was to evaluate the effect of probiotics on salivary IgA.Materials & Methods: This randomized, triple-blind trial was conducted on 40 healthy non-smoker volunteers. The subjects were assigned to two age- and sex-matched groups ingesting 200 g of a regular yoghurt (control) or a yoghurt containing probiotic bacteria (treatment group) once daily for 8 weeks. Unstimulated salivary samples were collected from the subjects at weeks 0, 4 and 8 of trial and total salivary IgA concentration was determined using ELISA. Saliva volume was measured and salivary IgA secretion rate was calculated. The differences in IgA means were statistically analyzed by repeated measurments (a=0.05).Results: Over the trial period, no significant changes were found among the salivary IgA concentrations of control group; however, treatment group presented a non-significant increase (P>0.05). There were not significant differences in concentration and secretion rate between two groups at each time point of study (P>0.05).Conclusion: Within the limitations of this study, an 8-week period daily consumption of probiotic yoghurt could not alter the salivary IgA concentrations, although it persuades an increase trend in salivary IgA secretion rate.

Introduction: Mucormycosis is a rare and invasive fungal infection with a high mortality that usually affects immunocompromised patients. The major route of infection is inhalation. An extensive necrotic ulcer in the mouth could be indicative of fungal invasion.Case report: A 67-year-old woman was visited in the department of Oral Medicine of Hamadan dental school with perforation and extensive and progressive ulcer in palate from 2 month ago. The patient had a history of swelling in the face and proptosis in the right eye from five months ago. Lab tests revealed an uncontrolled diabetes mellitus. Biopsy was carried out under clinical diagnosis of deep fungal infection and final diagnosis was mucormycosis.Conclusion: Early detection of mucormycosis could increase survival rate. Therefore, dentists can play an important role in primary diagnosis of the lesions. Systemic diseases could also be diagnosed and referred for treatment by the dentists.