Journal of Dental Medicine

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Normal 0 false false false EN-US X-NONE AR-SA Pleomorphic adenoma is the most prevalent tumor of salivary glands. In present survey, the cases are selected for analysis from 4 valid centers of the country. Of 573 salivary gland tumors, 342 (60%) were Pleomorphic adenoma of which 189 cases located in major salivary glands mostly in parotid gland and 145 cases in minor glands. This tumor is mostly seen in 30-50 year women.  The obtained data from patients and other reports indicated that Pleomorhic adenoma cases can be seen in other exocrine glands except pancreas.

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Normal 0 false false false EN-US X-NONE AR-SA The following reports are introducing 3 patients with progressive systemic sclerosis who had oral manifestations such as limited mouth opening, PDL thickening,... as well as uncommon internal resorption in many of their teeth with any etiologic factor. According to oral manifestations of systemic sclerosis, It seems that internal resorption can be associated to their systemic disease.

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Normal 0 false false false EN-US X-NONE AR-SA In 9 patients of 11-20 years old, Pulp response to phosphoric acid 37% during a 15 seconds etching period was studied. Class V cavities in cervical third of premolars were prepared as symmetrical couples. All the process was identical in both groups of case and control. In test group, 15 seconds etching period by phosphoric acid 37% was done. The teeth were then restored by ZOE. Only one case complained of pain and discomfort. After 1,2,4,6,12,24,56 days the teeth were extracted. In 100 sections made from extracted teeth of 5 patients , pulpal response to acid reaction was a mild inflammation with good prognosis.

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Normal 0 false false false EN-US X-NONE AR-SA One of the concerns od patients have been teeth stains particularly in anterior region. The etiology of this can be pulp necrosis, developmental disorders, drugs and systemic diseases. Bleaching or tooth whitening is a solution for some of these color changes. This article evaluated different methods of bleaching and their side effects . In case in which tooth whitening is needed,  attentive case selection should be done and advantages and disadvantages of each method should be considered in order to apply the best treatment among other options of bounding, veneering or crowning.

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Nucleolar organizer regions (NORs) are loops of rDNA, which in human, occur on the short arms of five acrocentric chromosomes, namely, 13, 14, 15, 21 and 22. NORs are usually demonstrated by binding If their associated proteins (NORAPsO to silver (Ag+) ions. The reaction is called AgNORs. It has been determined that, the number and the size of NORs is related to the proliferative activity and grade of malignancy. This has led to the application of AgNOR method to a wide range of diagnostic problem cases, including breast, salivary glands and lung malignant neoplasms.The purpose of this study was to determine the value of AgNOR method in assessment of the grade of malignancy in non- Hodgkin's lymphoma of head & neck, which often is difficult and essentially important in relation to the prognosis and treatment.41 cases of paraffin embedded specimens of NHL, which were classified by working formulation system,were selected and then AgNORs method was applied on them.AgNORs were enumerated for all 41 cases of NHL (Standard Crocker).The mean AgNORs in 11 cases of low grade 15 cases of intermediate grade and 15 cases of high grade NHL was 1.66 (SEM= 0.098), 2.25 (SEM= 0.084) and 5.19 (SEM= 0.11), respectively.In analysis of variance and multiple comparisons, a significant difference was found between the three groups of NHL (P<0.000I).It is concluded that the AgNORs, as a reliable method, could be used in differentiation of low,intermediate and high grade NHL in head and neck area.

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Frequently, diagnosis of lichen planus as a relative common chronic inflammatory mucocutaneous disease, is difficult, therefor, direct Immunofluorescence (DIF) examination is recommended for definite diagnosis. In this study both an statistical analysis of files of oral and maxillofacial pathology department of Dentistry school and direct immunofluorescence examination using paraffin blocks with new method, were performed. According to analysis of 8026 cases, 262 (3.26%) cases were diagnosed as lichen planus most patients were in fourth decade of their life and most common affected region was buccal mucosa, (69.68%).
In direct immunofluorescence study of 14 cases (using firth's method) fibrinogen deposits in 6 cases and immunostaining of colloid bodies with various immunoglobulins (IgA, IgG, IgM), C3 and also fibrinogen (few values) in most of patients, were detected. In spite of the fact that density of staining was lower than routine method (using fresh-frozen tissue), except for fibrinogen immunostaining, these findings are compatible with previous studies. In spile of limitation of samples, this study suggests that using this technique needs more evaluation and this can be used for diagnosis purposes when fresh-frozen tissue is unavailable.

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One of the major factors in a successful root canal therapy is the determination of root length before canal preparation. Radiography has been proved to be useful in this case, but nowadays for reducing radiation, radiovisiography has been recommended. The aim of this study was comparing conventional radiography (CR) with radiovisiography (RVG) in determination of canal length. 101 anterior and posterior extracted human teeth were selected. After mounting in unolit block, K- file (Num. 15) was placed in canal with tactile sense. Working length was measured by C.R and RVG. The results were analyzed by complete, randomized block design. RVG and CR showed shorter length than actual length. But, the measured lengths did not show significant statistical differences. As a result, considering the advantages of RVG, it is recommended in determining canal length.

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Various comparative studies have been conducted to investigate the effect of functional and fixed appliances in treatment of class II skeletal disorders. The aim of this study was to compare Bionator and Edgewise appliances associated with class II elastics in the treatment of class II skeletal patients, without extraction. Lateral cephalograms of 30 patients (16 girls, 14 boys), 10-13 years old, with class II div I maolocclusion, treated with Bionater and Edgewise appliances were investigated before and after treatment. SNA, SNB, ANB, " to SN, IMP A, mandibular and maxillary lengths, upper anterior facial height to lower anterior facial height, overjet and overbite were measured in each group before and after treatment. The results were analyzed by paired t- test. The magnification of linear measurements were calculated. The differences between variables in 2 groups were compared by t-test. There was no significant difference, regarding age and sex. In both groups, increase in SNB, mandibular length, and IMPA and decrease in " to SN, overjet and overbite and upper anterior face height to lower anterior face height after treatment were statistically significant. Comparing 2 groups before and after treatment showed that increase in SNB and decrease of ANB, overjet and overbite were more in Bionator group than fixed group, which were significant. Decrease in upper anterior face height to lower anterior face height, and increase in IMPA and mandibular length were more in Bionater group but the differences were not statistically significant.

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According to researches, premolar extraction and anterior teeth retraction result in temporomandibular joint disorder due to posterior position of mandible. The aim of this study was to evaluate the effect of premolar extraction on TMJ disorder. In this interventiond study, 4 groups (10 patients for each group) were treated.They were classified as 1- non extraction, 2- extraction of two upper first premolars, 3- extraction of four first premolars, 4- combined extraction groups. Helkimo scores were evaluated before treatment, after treatment, one and two years after treatment. The results were analyzed with ANOVA and paired t-test. At the end of the treatment and two years after treatment in comparison with before treatment, Helkimo score had Significant differentce in all groups (PO.001). In the second year after debanding in comparison with the first year after debanding, no significant differences were seen in each group. No significant difference was seen between the four groups in the final appraisal of TMD. It seems that extraction had no adverse effect on TMD.

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Statement of Problem: The goal of bone regenerative therapy is to reconstruct the damaged tissues to initial condition, which seems so important in periodontoiogy and implantology. In such therapies, different biomaterials, with some advantages and disadvantages, may by use.
Purpose: The aim of this research was to evaluate the quality, bone trabecular density and thickness of newly forming bone as well as foreign body reaction against Biostite®, in comparison with the control group.
Material and Methods: In this experimental study the total number of 5 sheep was operated with general anesthesia. At first 10 standard defects were created in 5x5x5mm on the left and right edentulous mandibular ridge. Five defects were randomly treated by Biostite®, the remaining five were considered as controls. After six months, the sheep were sacrificed and the separated defect areas with intact margin
were placed in 10% formaline and prepared for histologic and histomorphometric study. To analyze the data, Mann-Whitney U test was used.
Results: The mean percentage of new bone formation in Biostite® group was statistically more than the control group (PO.05). Newly formed bone was vital in both groups which was a combination of lamellar and woven types, however, the thickness and density of new bone in biostite® group was more than the controls. Foreign body reaction was observed in Biostite® group.
Conclusion: It is suggested that Biostite® synthetic material can be useful in bone regenerative
therapies.

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Statement of Problem: Dental practices such as oral, periodontal and endodontic surgeries cause damages to the intraoral tissues, so having knowledge of the dental procedures that necessiciate endocarditis prophylaxis is of high importance.
Purpose: The aim of the present study was to determine the knowledge level of dental senior students in Tehran dental faculties about endocarditis
Materials and Methods: In this cross- sectional descriptive- analytic study, 253 senior students of four dentistry faculties in Tehran took part as follows: Tehran University: 71 students (M:42, F:29), Shahid Beheshti University: 74 students (M:40, F:34), Shahed University: 35 students (M:35, F:38), Azad University:73 students (M:35, F:38). The questionnaire used in this research consisted of three parts as follows: part one:
information on cardiac diseases, part two: dental procedures requiring endocarditis prophylaxis, part three:antibiotic diet in endocarditis prophylaxis. Sex and place of education of the students were also studied in detail. For statistical analysis, Chi-square test was used.
Results: On the basis of the sex, the correct answers of the female respondents of different universities wereranked as: Azad University: 72.5%, Tehran University: 71.1%, Shahid Beheshti: 57%, ShahedUniversity:55.7%. In the same way, the male respondents were reported as: Tehran Universitys: 71.6%, Azad University:66.2%, Shahed University: 57.3%, Shahid Behesti University: 52.1%, On the basis of the place of education,the following results were reported: Tehran University students managed to answer 71.3% , Azad University,Shahed University and Shahid Beheshti University students could answer 69.5%, 56.5% and 54.6%,respectively. All these differences were statistically significant, indicating that first ranked students have more information than the students of other schools.
Conclusion: It is recommended to develop more practical training programme in dental schools on cardiac
diseases, dental procedures requiring endocarditis prophylaxis and antibiotic diets.

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Statement of Problem: Differentiation of dentigerous cyst from unicystic ameloblastoma, discovering any initial ameloblastic changes in lining epithelium of dentigerous cyst at early stage, and differentiation between hyperplastic odontogenic epithelium in fibrous capsule of dentigerous cyst from ameloblastic proliferation, need to an accurate and reliable technique.
Purpose: The aim of this study was to determine and compare Ki-67 immunoreactivity in various locations of the epithelium of Dentigerous cyst and Unicystic Ameloblastoma.
Materials and Methods: In this historical Cohort study, 15 cases of dentigerous cyst and 9 cases of unicystic ameloblastoma were selected. Immunohistochemistry staining was performed by M1B-1 (murine monoclonal antibody against Ki-67). The stained nucleous were counted in basal and suprabasal layer of lining epithelium of both lesions in 3000 epithelial cells. Finally, the percentage of positive cells (presented as labeling index) was calculated, t- student test was used to analyze the related data.
Results: Ki-67 (LI) in basal layer of Dentigerous cyst (2.59±1.66) and Unicystic Ameloblastoma (3.76±79) had no significant differences, but Ki-67 (LI) in suprabasal layer of unicystic ameloblastoma (2.15±0.69) was significantly higher than dentigerous cyst (0.77±0.55) P=0.003).
The difference between the average numbers of positive cells for Ki-67 (LI) in these two lesions was statistically significant (P<0.05) and it was higher in Unicystic Ameloblastoma than Dentigerous cyst.
Conclusion: Based on the findings of this study, it is suggested that Ki-67 (LI) in suprabasal layer or throughout the epithelium can be considered as a useful marker for differential diagnosis between dentigerous cyst and unicystic ameloblastoma.

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Statement of Problem: Root canal cleaning and shaping are important steps in endodontic therapy. In order to develop better techniques, new instruments are constantly designed and delivered to the market.
Purpose: The aim of the present study was to compare the effectiveness of one manual with three rotary root canal instrumentations techniques.
Materials and Methods: In this in-vitro study, 80 mesial roots of freshly extracted human mandibular molars were divided in to four groups equally and prepared by one of the following instrumentation methods profile NiTi rotary system, Protaper NiTi rotary system, Flex Master NiTi rotary system and hand NiTi K-file instrumentation. In each root one of the canals was instrumented and the other was used as control.After decalcification, cross sections at 3mm and 5mm of apical portion were prepared and examined for remaining debris, predentin and smooth walls under light microscope. The data were analyzed by Kxuskal-Wallis test.
Results: Significantly less debris was found at 3mm cross- section using protaper and Flex Master techniques (P<0.05). No significant differences were found at 5mm cross section. Also no significant differences were observed for remaining predentin at all regions. Significantly more smooth walls were found at both regions using protaper technique (P<0.05).
Conclusion: The protaper technique employed in this study resulted in cleaner root cana! walls than the
other techniques.

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Background and Aim: The hormone receptor status in breast cancer has been pivotal in determining the likelihood of response to hormonal manipulation. Tumors which are both estrogen and progesterone receptor positive are much more likely to respond to anti-hormone therapy than negative tumors. There is well-established similarity between breast tissue and salivary glands. The aim of this study was to evaluate the progesterone receptor expression in pleomorphic adenoma and adenoid cystic carcinoma of salivary glands.

Materials and Methods: In this descriptive study, immunohistochemical staining with progesterone antibody was performed on 14 pleomorphic adenoma (PA) and 15 adenoid cystic carcinoma (ACC) paraffin blocks. The percentage of positive cells was determined using an eye piece graticule. Immunoreactivity was categorized as either positive (reactivity more than 5%) or negative (reactivity less than 5%). In addition the existence of progesterone receptor in tumor cells, stromal cells (fibroblasts), inflammatory cells and salivary glands around tumors was evaluated. Data were analyzed with T and Mann Whitney U tests with p<0.05 as the limit of significance.

Results: Immunohistochemical staining for progesterone receptor was negative in 15 ACC and 13 PA. Only one case of PA showed immunoreactivity for progesterone receptor. Also, 12 normal salivary glands around tumor were positive. Inflammatory cells, endothelial cells and fibroblasts did not show immunoreactivity in most cases.

Conclusion: The results indicate the lack of progesterone receptor expression in ACC and PA of salivary glands.

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Background and Aim: Orthodontic ligature cutting pliers are expensive. Methods of sterilization should be safe considering patients' health as well as lifetime of orthodontic pliers. The purpose of this study was to compare the wear of orthodontic ligature cutting pliers after sterilizing with dry heat or steam autoclave.

Materials and Methods: In this experimental study, thirty ligature cutting pliers from 3 different factories (Dentarum-Germany, RMO and ETM-USA) were sterilized in either dry heat or steam autoclave. The amount of wear at the tip of each plier in both groups was measured with a stereomicroscope and digital photomicrography. Wear was defined as the difference of the initial length and the length after 10, 20, 30 cycles of sterilization measured by the distance from a reference line on the tip of the plier. Three way ANOVA was used to compare wear between the two sterilization groups. P<0.05 was considered as the limit of significance.

Results: The amount of wear of the ligature cutting pliers' tip after 10, 20 and 30 cycles in dry heat sterilization was 1.0±0.16, 0.98±0.22 and 0.94±0.31 mm respectively. These figures were 1.16±0.15, 1.16±0.13 and 1.15±0.14mm for steam heat sterilization. The higest wear was observed after 20 cycles of sterilization in autoclavce whereas the lowest was seen in dry heat sterilization after 30 cycles. The differences between the two studied groups were statistically significant (P<0.0001). In addition, increasing sterilization cycles decreased the rate of wear in both groups.

Conclusion: Based on the results of this study routine autoclaving caused more damage and wear at the tip of the pliers than dry heat sterilization.

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Background and Aim: The cell cycle is an important event in tumor growth and differentiation and several molecules are involved in this process. The aim of this study was to evaluate the expression of cyclin D1 (a cell cycle inducer) and p21 (a cell cycle inhibitor) in ameloblastoma of the jaws.

Materials and Methods: In this cross-sectional study, 40 cases of ameloblastoma were selected from the archive of oral pathology department. 3 micron sections were cut from paraffin blocks and immunohistochemically stained with antibody against cyclin D1 and p21waf. Stained cells were counted using an eyepiece graticule and labeling index was calculated. Data were analyzed by SPSS version 11.5 for windows using Mann-Whitney and Wilcoxon signed ranked tests with p<0.05 as the level of significance.

Results: Expression of cyclin D1 protein was detected in nuclei of many tumoral cells. The expression of cyclin D1 in solid and unicystic ameloblastoma and also between its follicular and plexiform variants was not statistically different (P>0.05). There was no statistically significant difference in expression of cyclin D1 between peripheral and central cells (P>0.05). Expression of p21 protein was detected in nuclei of some tumoral cells. There were no statistically significant differences between p21 expression in unicystic and solid ameloblastoma (P>0.05). P21 expression was statistically different between plexiform and follicular variants of ameloblastoma (P=0.049). The difference between p21 expression in peripheral cells of plexiform and follicular variants was statistically significant (P=0.009). This was not observed in central cells. There was no statistically significant relation between p21 and cyclin D1 expression in ameloblastoma (P>0.05).

Conclusion: Based on the results of this study, cyclin D1 expression in ameloblastoma is in high level and it could have an important role in the process of tumorigenesis. P21 expression in ameloblastoma is very faint and its possible effects need further investigation.

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Background and Aims: The aim of this in vitro study was to compare shear bond strength of metal brackets bonded to dental porcelain on the basis of presence or absence of silane, type of acid [hydrofluoric acid (HF) or phosphoric acid (H3PO4)] and roughness of porcelain surface (glazed or deglazed) within mouth-like environment.
Materials and Methods: Eighty glazed ceramic disks were randomly divided into 8 groups of 10 disks: group 1 [HF+silane], group 2 [deglazed+HF+silane], group 3 [HF], group 4 [deglazed+HF], group 5 [H3PO4+silane], group 6 [deglazed+H3PO4+silane], group 7 [H3PO4], group 8 [deglazed+H3PO4]. Then the brackets were bonded and thermocycled. After that, shear bond strength test was done using the Zwick device and the type of bond failure was determined under stereomicroscope at 4X magnification. 3-way ANOVA and Kruskal-Wallis were used for statistical analyses.
Results: The shear bond strength for the test groups were as follows: group (1):13.05±7.7 MPa , group (2):25.16±10.66 MPa, group (3):6.7±5.86 MPa, group (4):15.39±8.97 MPa, group (5):12.76±7.91 MPa, group (6):13.57±7.85 MPa, group (7):0.54±0.67 MPa, group (8): 9.34±6.52 MPa. The type of bond failure in all groups was adhesive failure except for group 2. No significant difference in the interaction between (glazed or deglazed), (presence or absence of silane), and type of acid was found (P>0.05).
Conclusion: Under the conditions of this study, the best clinical method was the use of 37% phosphoric acid and silane that resulted in the optimal clinical strength and adhesive bond failure.

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Background and Aims: Normative need assessments should be substituted or integrated by patient-based outcome measures regarding their shortages in health-oriented approach . This study aimed to assess and compare the ability of  an index of oral health-related quality of life measured by Child Oral Health Impact Profile (COHIP) questionnaire and the Aesthetic Component of Index of Orthodontic Treatment Need (AC-IOTN) to identify the normative need to orthodontic treatment using Dental Health Component-IOTN in a sample of the Iranian adolescents.

Materials and Methods: Target population of this cross-sectional analytic study was 597 of the 13 to 18 year-old schoolchildren enrolled in middle and high schools of the city of Isfahan, Iran. They completed the COHIP questionnaire and then were examined by two calibrated trained dentists (agreement coefficient:0.9) to record the DHC grading. The students scored their AC in according to the images of the scale. The association between subjective indicators and clinically defined need were evaluated by the correlation analysis and the statistics for the diagnostic validity of tests.

Results: Of 568 examined students, 16.7% and 2.1% had definite need according to DHC and AC criteria, respectively. 10% of orthodontic patients had perceived distinct impact on their quality of life. The significant association (P=0.001) between the severity of malocclusion and quality of life was at moderate level by AC (R=0.37), but it was not convincing enough by DHC (R=0.16). The specificity of AC to detect the healthy ones showed to be excellent but its low sensitivity disabled the recognition of patients, precisely.

Conclusion: The considered patient-based indices did not meet the competencies to define the orthodontic need in the adolescents, but it could be employed to identify the persons with impaired quality of life and it would probably benefit  the process of prioritization.

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  Background and Aims: The aim of this descriptive longitudinal study was to determine the type of teeth that were more prone in accidental bracket debonding and also to investigate the relationship between broken bracket bond and intervening factors such as age, type of malocclusion and sex.

  Materials and Methods: We used a pilot study to determine the correct sample size for this study. According to the pilot study which consisted of 20 records of patients, it was concluded that 576 patient’ records was needed. The mean time for a bracket before it fails was also measured using Kaplan-Meier method. Cox regression analysis was done to examine the effect of age, gender, and class of malocclusion on each tooth with broken bracket. Data were analyzed using the software SPSS 20.

  Results: Results showed that the percentage of unexpected broken bracket bond for each tooth varied and they were significantly related only in second premolars in both jaws with malocclusion that was different for each tooth (P=0.037, P=0.004).

  Conclusion: Maxillary second premolars and mandibular second premolars had the highest rate of unexpected broken bracket bond in CL II CL I malocclusion respectively. Age, gender and malocclusion had no effect on the unexpected broken bracket bond for other teeth.

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