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 This article is aimed to evaluate blood pressure changes in 100 patients (Normotensive and hypertensive) of dental clinics.  Blood pressure changes were recorded in particular stages: before surgery, 2 minutes after receiving local anesthesia, during surgery and 15 minutes post surgery. Results were analyzed via student paired T test to identify if there were any significant difference between two groups of normotensive and hypertensive and this was dangerous or significant enough to prohibit patients from receiving dental treatments.

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This syndrome is a genetical disorder with symptoms result from deficit in the formation of connective tissue, especially collagen fiber biosynthesis. In these patients, there is hyperelasticity and fragility of the skin and mucosa. Injuries sever bleeding, internal bleeding and hemartrosis may be seen in these patients. Wounds leave scars after healing. There is recurrent dislocation of the joints, especially knee and temporomandibular joints. Dentists should know the symptoms of this syndrome and its complications during dental treatments.

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Normal 0 false false false EN-US X-NONE AR-SA In order to evaluate the effect of chlorhexidine mouthwash in controlling oral complications of chemotherapy, 146 patients were recruited among the patients referred to heamatology department of Shariati hospital who were under treatment by routine chemotherapic drugs like EBDV, CMF or FU-Lucoverin5 for first, second or third time. The patients were  allocated into two groups to receive either chlorhexidine or Placebo  for a week after careful examination and evaluation. Finally, It was concluded that Chlorhexidine is effective to reduce oral complications of chemotherapy (P-value≤0.002).

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The purpose of this article is to study distribution of DMF(T) and its D,M and F protions exactllly. 1500 subjects were examined clinicaly. They were 5 to 70 years old, with average 24 years. Only cavitated and coronal dental caries included in this research.

 The results of this study are:
1. The caries lesions of upper and lower second permolars are equal.
2. Anterior to second premolars, the DMF(T) of upper jaw teeth is higher than lower jaw's one. Conversely posterior to second premolars, lower jaw teeth has higher DMF(T).
3. Deciduous teeth of females have lower DMF(T).
4. Permanent teeth of females have higher DMF(T).
5. The upper Canines of females are exceptions. Upper canines of females have lower DMF(T) than males' ones.
6. It seems that sex hormones influence DMF(T) through Saliva and eruption time of teeth.
7. Susceptibility to Caries relates to microbial plaque formation and salivary protection.
8. The females have more filled teeth than males.

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Resin-bonded fixed partial dentures (F.P.D) can be used for conservative treatment of partially edentulous patients. There are numerous studies regarding the strength of resin composite bond to base meta! alloys. Shear bond strength of three resin systems were invistigated. In this study these systems consisted of: Panavia Ex, Mirage FLC and Marathon V. Thirty base metal specimens were prepared from rexillium III alloy and divided into three groups. Then each group was bonded to enamel of human extracted molar teeth with these systems. All of specimens were stored in water at 37ac for 48 hours. A shear force was applied to each specimen by the instron universal testing machine. A statistical evaluation of the data using one-way analysis of variance showed that there was highly significant difference (P<0.01)between the bond strengths of these three groups.The base metal specimens bonded with panavia Ex luting agent, exhibited the highest mean bond strength. Shear bond strength of the specimens bonded to enamel with Mirage F1C showed lower bond strenght than panavia EX. However, the lowest bond strength was obtained by the specimens bonded with Marathon V.

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Helicobacter pylori infection causes gastric and duodenal ulcer. However recurrence of infection after eradication would suggest the existence of other reinfecting sources in the gastrointestinal tract (Gl). The aim of this study was to assess the existence ofhelicobacter pylori in dental plaques of patients harboring Helicobacter pylori in their GI tract. Antral biopsies were taken from 40 patients with Gl problems and cultured. Samples were also taken from dental plaques of patients with positive Helicobacter pylori culture under microaerophilic conditions and evaluated by polymerase chain reaction (PCR) reamplification. The mean age of patients was 40 years 24 (60%) male and 16 (40%) female. The results obtained from dental plaque cultures, which analysed by PCR were all negative, however 7 (17.5%) cases were found positive by PCR reamplification. The results showed that Helicobacter pylori could exist in dental plaque and PCR reamplification could be used for its detection as a more sensitive technique. More research should be conducted to examine any relation between the existence of Helicobacter pylori in dental plaques and recurrent GI disorders.

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 Polymerization shrinkage of light cure composite resins causes many complications in conservative and esthetic restorations. The objective of this in-vitro study was to evaluate the polymerization shrinkage, degree of conversion and the amount of filler in IDM and tetric ceram composites. Ten disk shaped, uncured specimens (8mm×1.547mm) of each composite were placed on glass slide in the center of the metal attached to it. Then specimens were light cured for 60s from underneath. After 30 minutes, the thickness of specimens, using a micrometer and the percent of the polymerization shrinkage of each sample were measured. Statistical analysis was carried out by t-test (P<0.05). Also the degree of conversion of specimens was evaluated with FTIR and the mineral filler content was measured by burning in electric oven. Polymerization shrinkage in IDM and tetric ceram was not significantly different. Degree of conversion and mineral filler content in tetric ceram was greater than that of IDM.

It is assumed that the low degree of conversion in IDM is due to its chemical composition and filler content. Also, the similarity in linear polymerization shrinkage between IDM and tetric ceram may be caused by the low degree of conversion in IDM.

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Melanoma is a malignant tumor that originates from melanocyte cells. Its oral type is rare. The goal of this investigation was to determine the prevalence of oral malignant melanoma in Iran, as determined by age, sex and location. This research reviewed 623 cases of oral and non-oral malignant melanoma in Immam-Khomeini hospital, Mearaj cancer institute and department of oral pathology of dental faculty, Tehran University of Medical Sciences in a period of 19 years from 1981-1999. The results showed that 54 cases of biopsy lesions were melanoma of oral cavity that included 7.8% of these lesions. The mean age incidence of oral melanoma was 55.5(between 26-86 years). The most prevalent sites were palate (37.1%) and alveolar mucosa (20.4%) and less common sites included floor of mouth. buccal mucosa and tongue.

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During pregnancy, different froms of periodontal disease such as pregnancy gingivitis, pregnancy tumors, pregnancy stomatitis, may be encountered. But the most considerable point is the pregnant women's infection with periodontal disease and its effect on delivery and weight of newborn infants. Based on the latest researches and statistics, it is concluded that periodontal disease is an important risk factor, leading to preterm or premature delivery. On the other hand, poor hygiene, should be considered as another danger, resulting in premature delivery. Besides, the presence of a collection of oral fosobacteria in ammoniutic fluid in mothers with premature delivery, increases the probability of an oral- haematogenous connection. Moreover, prostaglandin E2, in cervicular fluid, has been considered as an index for periodontal disease activity and loss of weight at the time of birth. These findings suggest that effective steps, to prevent preterm delivery, can be taken, if women, genycologists and dentists have enough knowledge. This article focuses on the special supervision that is required to prevent the effects of hormonal changes on periodontal tissues and conversely to reduce systemic disorders resulting from periodontal disease, in pregnant woman.

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Muscular pain is one of the most common causes for facial pain. Myofacial pain dysfunction syndrome (MPDS) is one of the most important disorders of facial area that affected patients suffer from pain, tenderness of one or more masticatory muscles and limitation of movements. Lack of specific and effective therapeutic method, makes it necessary to find a treatment to decrease pain. Considering the analgesic and anti- inflammatory effects of low-level laser, some investigators have recommended it for MPDS patient's treatment. In this study, the effects of low level laser (Ga-Al-As) on MPDS patients referred to dental faculty of Tehran University of Medical Sciences, were investigated. Twenty- two MPDS patents, with mean age 33.32 years, were treated for 4 weeks (12 visits). Clinical examinations were performed in 6 stages. The results of this study showed that variables such as pain severity, cheek pain, pain frequency and tenderness of masseter, temporal, internal and external pterygoid muscles, had a statistically significant improvement at the end of treatment with low level laser (GA-A1-AS) which lasted for three months, (follow- up period). Results of this study showed that, low-level laser therapy has a sedative effect on the pain and tenderness of masticatory muscles in MPDS. Patients and having an accurate and regular program to complete treatment period, has an important role in MPDS improvement.

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Statement of Problem: Bone material density (BMD) is significantly decreased among postmenopausal women leading to the most common metabolic disease, osteoporosis.Multiple bone fractures are of the most important consequences of this disease, which cost too much for the
society. One of the cheapest and most available methods for the diagnosis of bone density changes is bone radiomorphometric evaluation by conventional methods. Studies have also revealed that mandibular radiomorphometric indices in panoramic radiographs yield invaluable information, which can be used as a screening method to diagnose patients with decreasing bone density, and to determine normal values of
mandibular radiomorphometric indices among normal subjects in different populations.

Purpose: The aim of the present study was to investigate the mandibular radiomorphometric indices in panoramic radiographs among normal female population referring to maxillofacial radiology centers to determine their relationship with age and the total teeth number of the subjects under study.

Material and Methods: In this descriptive-analytic study, two mandibular radiomorphometric indices namely the Antegonial quantitative index (AI) and the Cortical qualitative index (MCI) were evaluated on 417 panoramic radiographs of a female normal population, aged more than 20 years which divided into five age group, by one maxillofacial radiologist as an observer. The relationship between these indices, and also with the number of teeth and age were investigated by variance and Pearson's analysis.

Results: Mean quantitative index (AI) was 3.54±54%mm. The prevalence of MCI index was C2: 71.5%,CI: 20.9%and C3: 7.7%. There was significant correlation between AI/MCI indices with age, dentition and also with each other.(P<0.0001).
Conclusion: Based on the present study, with increasing age the mean AI and the number of teeth decrease significantly. MCI index also shows higher porosity in mandibular cortex (C3 index). Therefore, Mandibular radiomorphometric indices are useful in initial diagnosis and screening of patients with low bone mineral density (osteopenia, osteoporosis).

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Statement of Problem: Tooth extraction is always considered as the final treatment option in dentistry.Considering the numerous advances in dentistry, nowadays the preservation of the permanent teeth until old age is common. However, in most economically poor countries or those without security service insurance,the high rate of extraction, particularly among restorable teeth, is regrettable.
Purpose: The aim of the present study was to determine the reasons for tooth extraction among patients referred to the faculty of Dentistry, Tehran University of Medical Sciences in 2002.
Materials and Methods: This descriptive and cross-sectional study was conducted on 320 patients. The information about patient's general knowledge, oral health status, tooth location and causes of extraction were collected and recorded in a questionnaire. The data were submitted to statistical Chi-Square test.
Results: No statistically significant difference was found between two genders in their mentioned causes for extraction. The most prevalent reasons were as follows: Caries (50%), Periodontal diseases (16.6%). Absence of an acceptable occlusion, prosthetic problems, patient's request, etc... make up the remaining 33.4% of the reasons.
Conclusion: According to this study, it is suggested to investigate extraction etiology at the society level and if similar results are obtained, necessary steps should be taken to prevent caries and periodontal problems as the major mentioned causes for tooth extraction.

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Statement of Problem: Considerable response to functional orthopedic appliances treatment in class II skeletal patients occurs during pubertal growth spurt. Therefore, it seems necessary to investigate indices indicating mandibular growth pattern. It has been proved that analyzing cervical vertebral maturation stage is a more valid index than that of hand wrist.

Purpose: The aim of this study was to evaluate the time status of functional orthopedic treatment in class II skeletal patients using CVMS index.

Materials and Methods: In this descriptive-inferential study, lateral cephalometric radiographs of 153 class II skeletal patients with mandibular deficiency, before treatment, were studied by an oral and maxillofacial radiologist using the index of cervical vertebral maturation stage (CVMS) and were categorized in three phases: CVMS I (desirable phase of treatment), CVMS II (ideal phase), and CVMS III (undesirable phase of treatment).

Results: Statistical analysis ranked the prevalence of treatment phases as: 41.8% in desirable phase (CVMS I), 28.1% in ideal phase (CVMA II) and 30% in undesirable phase (CVMS III). No significant differences were found between the three phases using Chi-square analysis. Time status of functional orthopedic treatment was also evaluated based on age and sex. The results showed significant differences between two sexes (P=0.032).

Conclusion: The present study suggests the analysis of CVMS index, along with clinical criteria, in the determination of an ideal time for functional orthopedic treatment to prevent patients’ exhaustion during treatment Period.

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Evaluation of skeletal age and determination of growth status had important and special roie in orthodontic treatment planning (such as functional orthopedic treatment and orthognatic surgery) and also in stability of it. There were several biologic indicators for the detection of the peak in mandibular growth. Due to the limitations of biological indicators application, idea of new indicators was seemed importantly. Cervical vertebral maturation (CVM) method is one of them. At first the detection of the peak in mandibular growth was based on the analysis of the second through sixth cervical vertebrae in six developmental stages. But a few improvements of the original CVM analysis were still needed. In this method, the peak in mandibular growth was determined based on the analysis of the second through fourth cervical vertebrae in five developmental stages. This method is easy, applicable and more valid than hand-wrist analysis method.

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Statement of Problem: Computed tomography (CT) has proved to be the most precise method to evaluate the quantity of jaw bones.In recent years, patient dose which is much more greater in CT than conventional methods has attracted more attention, and has brought the idea of using the conventional method in more accurate ways or applying new methods with lower doses.

Purpose:radiovisiography for presurgical evaluation of endosseous implants.

Materials and Methods: measured with the two aforementioned techniques. To determine the magnification factor, an acrylic stent with spherical lead markers with known diameter, has been used. Then in intra-operative phase, this distance was measured directly on the patient’s jawbone. To assess the significance of differences from radiography results and the gold standard the binomial distribution was used.

Results:significant and there was no significant difference between RVG and visual method.

Conclusion:to conventional tomography. 

Radiography is the main tool for presurgical assessment of endosseous implants.The goal of this study was the assessment of the accuracy of conventional tomography andDistance between alveolar margin and superior border of mental foramen wasFindings showed that the differences between conventional omography and visual methods wereThis study revealed that the radiovisiography method showed more precise results in comparison

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Statement of Problem: Root canal cleaning and elimination of the source of infection are the most important basis and the main requirements for successful root treatment since the main cause of failure in root treatment is the permeation of bacteria or their products into the periapical tissues. Nowadays, the newly designed and prcsented instruments for canal instrumentation can improve root treatment.

Purpose: The aim of this study was to compare the decrease in the number of intracanal Enterococcus-faecalis (Ef) among three mechanical instrumentation methods: manual (K-type) and rotary (Race, Profile).

Materials and Methods: In this experimental study, 30 single rooted teeth were selected. Three cases were considered as negative and three cases as posetive controls and 24 remainder cases were divided into three experimental groups. All root canals were inoculated by Ef and samples were taken from all canals to prepare microbial cultures. The three instrumentation procedures were: - Crown- down technique with K-type manual system file - Crown- down technique with Profile rotary system - Crown- down technique wiht Race rotary system After instrumentation, microbial cultures were taken from root canals and the reduction rate of bacteria were evaluated and compared using one way ANOVA test with P<0.05 as the limit of significance.

Results: There was no significant difference among the three instrumentation procedures regarding bacterial elimination.

Conclusion: According to the finding of this study, K-type manual file, Profile and Race rotary systems, all can be used in canal instrumentaion. However, since manual files are more accessible and require less equipment compared with rotary systems, and since the ability of all of these methods is identical regarding bacterial elimination, manual files can be used in straight canal instead of rotary systems.

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Statement of Problem: Ceramic restorations are popular because they can provide the most natural replacement for teeth. However, the brittleness of ceramics is a primary disadvantage. There are various methods for strengthening ceramics such as metal framework, ceramic cores, and surface strengthening mechanisms through glazing, work hardening and ion exchange.

Purpose: The purpose of this study was to evaluate the effect of polish on flexural strength of feldspathic porcelain and to compare it with overglaze and autoglaze.

Materials and Methods: In this experimental study, one brand of feldspathic porcelain (colorlogic, Ceramco) was used and forty bars (25×6×3 mm) were prepared according to ISO 6872 and ADA No. 69. The specimens were randomly divided into four groups: overglazed, auto glazed, fine polish and coarse polish (clinic polish). Flexural strength of each specimen was determined by three point bending test (Universal Testing Machine, Zwick 1494, Germany). Collected data was analyzed by ANOVA and post-hoc test with P<0.05 as the limit of significance.

Results: A significant difference was observed among the studied groups (P<0.0001). According to post-hoc test, flexural strength in overglaze and fine polish group were significantly stronger than clinic polish and autoglaze group (P<0.001). Although the mean value for overglazed group was higher than fine polish group, this was not statistically significant (P=0.9). Also no statistical difference was seen between autoglazed and coarse polish group (P=0.2).

Conclusion: Based on the findings of this study, flexural strength achieved by fine polish (used in this study) can compete with overglazing the feldespathic porcelains. It also can be concluded that a final finishing procedure that involves fine polishing may be preferred to simple staining followed by self-glazing.

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Background and Aim: With the introduction of porcelain veneers to fulfill patients’ esthetic needs, question raises about the ability of the veneers to cover the substructure discoloration. It seems that using shade modifiers under the porcelain veneers can neutralize the discoloration. The goal of this study was to determine the efficacy of shade modifiers in correcting tooth discoloration, when used with resin cements under porcelain veneers.

Materials and Methods: In this experimental study, 60 porcelain discs with two thicknesses of 0.7 mm and 2 mm (30 porcelain of each thickness) were made from ceramco porcelain powder. 40 of them were in A2 shade and 20 were made by the mixture of A2 shade porcelain powder and porcelain stain to represent tooth discoloration. Then all the laminate discs (0.7 mm) were cemented over the 2 mm thick discs to make groups of 10 samples as followed: 1- The first group: laminate discs + resin cement + 2mm thick discs with A2 shade. 2- The second group: laminate discs + resin cement + 2mm thick discolored discs. 3- The third group: laminate discs+ resin cement+ shade modifier+ 2mm thick discolored discs. The color of 30 specimens was measured by spectrophotometer in 2 conditions. 1- To include the specular reflection (SCI). 2- To exclude specular reflection (SCE). In each condition the specimens were measured on both a white background (W) and a black one (B). The mean color differences (E) of each specimen in the second and third group with the specimens of the first group were calculated. Data were analyzed using Paired sample t-test and P<0.05 of significance.

Results: Color measurements showed that in SCIW condition L was significantly different among the three groups except the first and the third. In SCEW condition all the parameters showed significant differences. In SCIB condition, E was not significantly different between the second and the third groups. Hue (h) parameter wasn’t different between groups one and three neither was chroma (c) among the three groups. In SCEB condition, E was not statistically different between groups two and three.

Conclusion: Considering the statistical results, shade modifier couldn’t completely match the color of the specimens in the third group with the first one. But, the lower E for the third group comparing to the second one means that shade modifier was successful in reducing the effect of substructure discoloration.