Showing 143 results for Ph
A. Taghavi Zenouz , R. Sobuti , Sh. Jafari , B. Nikbin ,
Volume 16, Issue 4 (1-2004)
Abstract
Statement of Problem:Recurrent aphthous stomatitis (RAS) is a common oral disorder that despite extensive researches, the etiology of this phenomenon is still unknown. Because this phenomenon has been observed more often in families than in individual cases, genetic influence has been investigated in most researches.
Purpose: The aim of the present study was to evaluate the association between Human Leukocyte Antigen (HLA) and aphthous stomatitis more precisely.
Materials and Methods: in this study, 60 patients with RAS were examined for HLA-A and HLA- B types and 37 of them were examined for HLA- DR and HLA-DQ types. The results were compared through Fisher test with those of 25 healthy control subjects, aged more than 30 years.
Results: A significant decrease in the frequency of some antigens such as HLA-DQW 3 and HLA-A 26 in subjects with RAS was observed. Therefore, according to the results of this study, these antigens were considered as resistant antigens to recurrent aphthous stomatitis. In contrast, there was no significant increase in the frequency of any HLA antigens in the test group, compared to the control group. This finding is in contrast with the multiple reports about Behcet's disease. (Because a high frequency of HLA-B 51 has been
found in Behcet's syndrome.)
Conclusion: According to the findings of this study, it is suggested that the pathogenicity of aphthous ulcerations in Behcet's disease and recurrent aphthous stomatitis is not the same. However, further studies are necessary to prove this theory.
Ar. Talaeipour , M. Panjnoush , N. Anbiaei ,
Volume 17, Issue 1 (4-2004)
Abstract
Statement of Problem: Subtraction is a newly presented radiography technique to detect minor density changes that are not visible by conventional radiography.
Purpose: The aim of this In-vitro study was to evaluate the efficacy of photoshop subtraction software for detecting minor density changes between two dental images.
Materials and Methods: In this research, five dried human mandibles were held in fixed position while thin aluminium sheets were superimposed on each mandible on the 1th and 2nd molar teeth regions.A reference image, without aluminium sheet placement, was obtained from each mandible subsequently series consist of 20 images with aluminium sheets, ranging from 50p. to "5Q0"x were recorded by radiovisiography (RVG) system. Initial images were subtracted from subsequent ones by Photoshop subtraction software. The difference in density between the two images at the 1st and 2nd molar sites was related to the aluminium sheets. The optical density of aluminium sheets was determined by densitometer.
Results: In the present study, 6.6% of the optical density changes of the minimum aluminium thickness as 300u. could be detected by photoshop software software.
Conclusion: The findings of this study showed that the accuracy of photoshop subtraction software was equal to that of the conventional subtraction softwares. Additionally, the accuracy of this software was proved to be suitable for clinical investigations of small localized changes in alveolar bone.
H. Bashizadeh Fakhar , Sa Fatemi Tabar ,
Volume 17, Issue 1 (4-2004)
Abstract
Statement of Problem: One of the major goals, in most dental researches, is to measure bone destruction or deposition due to the progression or regression of disease. Failure of human eyes to detect minor radiographic density changes resulted in more accurate methods such as optical densitometry and direct or indirect digital densitometry.
Purpose: The aim of this study was to determine the accuracy of a newly proposed method of indirect digital densitometry using modified Photoshop software.
Materials and Methods: Radiographs from 37 samples of urografin solution with three concentrations (12.5%, 25% and 37.5%) were taken on dental radiographic films no.2 and digitized by a scanner. A region with 800*800 pixels was cropped from each image and compressed with the Joint Photographic Experts Group (JPEG) compression algorithm and saved. These new images were then put into registration with new algorithm using MATLAB software version 6.1. This algorithm assigned each image and average pixel value (between 0 and 255). The association between concentration and calculated values for each image was tested with regression analysis and the meaning fullness of differences between calculated values was also analysis by ANOVA test. Tukey HSD and Alpha Krunbach were used whenever needs.
Results: Regression analysis revealed significant correlation between concentration and calculated average pixel value (r=0.883). The differences between average of pixels value for different concentration was significant (P=0.0001). Pixel values showed a good intra- sample and intra-group repeatability (Alpha Krunbach: a=99.96%, a=99.68%).
Conclusion: This method due to its high accuracy, easy usage and densitometer independency can be considered as a suitable alternative for conventional densitometry methods.
D. Goodarzipoor, Sh. Shahrabi Farahani , H. Vahedi Gashniani ,
Volume 17, Issue 2 (6-2004)
Abstract
Statement of Problem: One of the dental lesions which is mainly diagnosed by periapical radiography is apical root resorption Diagnosis of the presence and extension of this lesion can put some effects on its treatment plan and prognosis.
Purpose: The aim of the present study was to evaluate the efficacy of periapical radiography on apical root resorption diagnosis. Materials and Methods: In this experimental study, sixty extracted teeth were examined radiographic and histological regarding the presence and extension of apical root resorption. It should be noted that periapical radiographs were taken before extraction of all mentioned teeth. The results were analyzed by Fisher’s exact test.
Results: The results of this study showed significant differences between radiological and histological examinations (P=0.0003). Significant correlation between these two observations was seen only in 53.33% of cases comprising 23% of teeth with root resouption. Non-correlation was found in 46% of samples. Moreover, there was no significant difference in the prevalence of apical root resorption between maxillary and mandibular teeth (P=0.233). Sensitivity of periapical radiographs in apical root resorption diagnosis was determined 57.3%. Conclusion: According to the findings of the present study, it seems that periapical radiography technique does not possess desirable efficacy in diagnosis of apical root resorption and its limitation should be considered by clinicians.
Aa. Khoshkhoonejad , A. Khorsand , F. Rastgar ,
Volume 17, Issue 2 (6-2004)
Abstract
Statement of Problem: Systemic analgesics are frequently prescribed for pain reduction following periodontal surgery. This type of treatment, however, brings about some disadvantages due to its late effect and inherent side effects. Benzydamine hydrochloride mouth wash is a non steroidal anti-inflammatory drug with local anaesthetic properties. Side effects of benzydamine are minor such as tissue numbness, burning and stinging. It brings relief to pain and inflammation rapidly.
Purpose: The goal of this study was to compare benzydamine HCL 0.15% and Acetaminophen codeine as analgesics following periodontal surgery.
Materials and Methods: This clinical study was performed on 18 patients referred to periodontics Department, Faculty of Dentistry, Tehran University of Medical Sciences. All patients were affected with chronic mild or moderate periodontitis and required surgery at least at two oral sites with similar lesions. Each patient received benzdamine HCL after first surgery and Acetaminophen codein following second operation. Pain reduction was evaluated by Visual Analog Scale (VAS). Data were analyzed with Wilcoxon-Signed and Mann-Whitney non-parametric tests. Results: Analgesic effect of Acetaminophene codeine was significantly more than that of benzydamine HCL following Reriodontal surgery (P=0.008). No significant difference was found between analgesic effects of Acetaminophene codeine and benzydamine HCL in patients with chronic mild periodontitis (P=0.9), and in cases that osteoplasty (P=0-31) or no osseous surgery (P=0.18) were performed.
Conclusion: In cases with mild post-operative pain following periodontal surgery, Benzydamine HCL and be prescribed as an analgesic. However, in other cases this mouth wash should be prescribed along with Acetaminophene codein to reduce systemic drugs consumption.
Z. Kadkhoda , S. Sanjabi ,
Volume 17, Issue 3 (8-2004)
Abstract
Statement of Problem: Elimination of porphyromonas gingivalis (p.g) from subgingival area in order to successfully treatment out comes in patients with Aggressive periodntitis AP is necessary.
Purpose: The aim of this study was the evaluation of non-surgical treatment efficacy in reduction of bacterial population in deep pockets.
Materials and Methods: In this randomized clinical trial study we evaluated the result of non- surgical therapy on reduction of p.g count from deep pockets of patients with aggressive periodontitis that had at least one (p.g plus) deep pocket (>5mm) in each quadrant. At first stage of non-surgical treatment intra pocket irrigation with chlorhexidin was done after scaling and root planning for all patients. In second stage (one week later) antibiotics including amoxicillin- metronidazol prescribed for ten days. At base line, one, six and twelve weeks after beginning of therapy, microbial samples, plaque index, bleeding on probing index and probing pocket index were recorded.
Result: There was statistically important difference between one and six weeks after treatment with base line in colony count of p.g and all of clinical indices. But in 12 weeks after therapy just, PI and PPD had statistical difference with base line. In this stage, colony count and BOP was reduced but this reduction had not statistically important difference with base line.
Conclusion: Thus in present study our non- surgical strategy in elimination of p.g and clinical improvement was successful in short time but three month after therapy recurrence of disease happened in some patients.
Mt. Chiisazi , Kaviarri F., J. Yazdani ,
Volume 17, Issue 4 (1-2005)
Abstract
Statement of Problem: In spite of the limitations of Radiography, diagnosing of periodontal diseases without having accurate radiographs is inadequate because it provides a visible image of the supporting bone to the clinician and works as a fixed measure of the supporting bone during the study.
Purpose: The aim of this study is to compare the precision of preiapical, bitewings and panoramic radiographs in determining the distance between the alveolar crest (AC) and cementoenamel junction (CEJ) of teeth.
Materials and Methods: Statistically this is a survey study in which 120 interproximal surfaces of teeth were measured during surgery by periodontal probing and recorded as the actual measurement. Then 40 sites underwent bitewing, 40 sites preapical and 40 others panoramic radiography and the distance of CEJ up to the alveolar crest of bone was measured on them by periodontal probe and recorded. Then each group was analyzed separately and the Pearson's correlation coefficient was examined for the data.
Results: The results of this study showed that when the thickness of the remaining bone in a millimeter limit
is important for (he surgeon, the bitewing radiography has a prime importance, but when bone loss is
moderate, the panoramic radiography showing %89 of the cases close to the actual measure, can be
acceptable. On the other hand, in anterior sites for determining the bone alteration, preiapical radiography
with a 0.93 correlation coefficient is superior to the panoramic radiography with a correlation coefficient of
0.72 and we suggest it for examining the changes of bone in these sites.
Conclusion: whenever the bone alteration is moderate or severe, it seems that, bitewing radiography is of
particular importance, but when the bone loss is little, panoramic radiography can be used and there is no need
to put the patient on unnecessary radiation.
Mb. tavakoli , R. Tabarak , A. zargar ,
Volume 17, Issue 4 (1-2005)
Abstract
Statement of Problem: Zinc contained cements are so important among dental material as they have many indications and used in different ways therefore evaluation of their physical properties is so important in dentistry.
Purpose: The purpose of this research was to measure some physical properties of zinc-contained cements used in restorative dentistry. These cements included: Zinc oxide-eugenol, Zinc phosphate and Zinc polycarboxylate. Physical properties measured in this research were compressive strength, and setting time also Solubility & Disintegration were evaluated.
Materials and Methods: To perform this research two packs of each cement type were provided from an Iranian company products as prototypes and German HARVARD Dental GmbH company products as proof samples. For compressive strength 11 samples provided from any type of cement. For setting time test, 16 samples provided from Zinc oxide-eugenol and 11 samples from two other types. For solubility &
disintegration beet, 11 samples provided only from Zinc oxide-eugenol cement. The results compared with standard.
Results: The results of Iranian product showed that compressive strength of Zinc oxide-eugenol- is I2.58±3 MPa, of Zinc phosphate cement is 37.2I±5.0 MPa and of Zinc polycarboxylate cement is 35.86±2.1 MPa.Setting time of Zinc oxide-eugenol cement is 2 9.04 ±0.7 1 min, of Zinc phosphate cement is 5.41 ±0.55 min and of Zinc polycarboxylate cement is 2.5±0.6 min. Solubility & disintegration of Zinc oxide-eugenol cement is 8.44±i.l%. None of these findings are in standard limit.
Conclusion: By the use of standard charts it is concluded that: Only compressive strength of Zinc oxide-eugenol cement is between standard limits and compressive strengths of two other types of the cements are less than standard limits. Also only setting time -of Zincoxide eugenol cement is in standard limit and setting times of two other types of the cements aren't in standard limit. The German samples results were in standard limit. Solubility & disintegration-of Zinc-oxide eugenol cement isn't in standard limit. Therefore it is concluded that all types of these cements are not standard for use.
Mh. Toodeh-Zaeim , H. Ravanmehr ,
Volume 17, Issue 4 (1-2005)
Abstract
Statement of Problem: The significance of adenoid tissue in Orthodontia appeared in 1954. At that time,even as today, orthodontists had an enduring interest in the relationship between excessive amounts of adenoid tissue, the developing occlusion, and facial morphology.
Purpose: The aim of this study was to evaluate effect of mouth breathing with adenoid enlargement on dentofacia! cephalometric measurements.
Material and Methods: A sample of 92 subjects between the ages of 6 and 15 years old were studied in two study and control groups. In study group, 46 mouth breathers (32 girls and 14 boys) with mean of 1 1.26 years old were examined by orthodontist and ENT specialist in order to confirmation of nasopharyngeal obstruction.Control group contained 46 nasal breathers (35 girls and 11 boys) with mean of 11.33 years old. For each patient in centric occlusion, a lateral cephalogram was taken and traced. 12 dentofacial variables were measured and statistical t-test was conducted by calculating the mean, standard deviation and p-value of parameters. Statistical t-test for mean oi~ dentofacial variables for the two groups revealed that some of variables were significantly different.
Results: In study group Z Go.Me-SN, Z Y-A.xis, Z Go, Z SN-PL variables were significantly higher than control group and Z HoFIl, Z SNB were significantly lower. The other dentofacial variables (ZS, IMPA,Z SNA, Z ANB. Z Ar and LH) didn't show any significant difference.
Conclusion: Adenoid enlargement and nasopharyngeal obstruction can affect dentofacial morphology and cause facial vertical growth pattern and upper centrals retrusion.
N. Jalayer Naderi , Sm. Latifi , F. Ahmadi Nejad ,
Volume 18, Issue 1 (3-2005)
Abstract
Statement of Problem: Giant cell granuloma (G.C.G) is a reactive lesion which affects the jaws and oral mucosa of gingiva.This lesion is classified to central and peripheral ones. The histopathologic aspects of central and peripheral G.C.G is the same. The central lesions are aggressive and cause osseous destruction. The peripheral G.C.G produces ulcerative swellings similar to pyogenic granuloma or peripheral ossifying fibroma. Since the peripheral and central G.C.G are common lesions, the awareness of dentists of different aspect of G.C.G is very important.
Purpose: The aim of this study was a statistical evaluation of variables such as age, gender and location of peripheral and central G.C.G in oral and maxillofacial pathology department of Dental Faculty of Tehran University of Medical Sciences.
Materials and Methods: This study was a cross-sectional, case series one. The medical records of oral and maxillofacial pathology department of Dental Faculty of Tehran University of Medical Sciences was assessed in two steps: In the first stage, the medical records of patients with pathologic report of peripheral and central G.C.G were selected and reviewed. In the next step, the informations such as age, gender and location of peripheral and central G.C.G were registered in data forms. The obtained data were analyzed by SPSS statistical software.
Results: The results showed that the age range in peripheral and central G.C.G were 2- 90 and 4-70 years, respectively. The peak incidence of peripheral and central G.C.G was in the third and second decades, respectively. The peripheral G.C.G was more common in men (52.70%) than women (47.30%). This finding in central G.C.G was 37.19% for men and 62.88% for women. 57.06% of peripheral G.C.G cases were in mandible and 42.94% in maxilla. The occurrence of central G.C.G was 67.07% in mandible and 32.93 % in maxilla.
Conclusion: Based on this study, the peripheral lesions were more frequent in men, third decade and mandible and the central lesions in women, second decade and mandible.
M. Paknejad , S. Eshraghi , M. Jafari-E- Ghajar ,
Volume 18, Issue 1 (3-2005)
Abstract
Statement of Problem: One of the best ways for treatment of Aggressive Periodontitis (AP) is identification and elimination of etiologic factors specially two microorganisms Actinobacillus actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) in patients harboring them.
Purpose: This study determines the prevalence of Aa and Pg and its correlation with age, sex and the number of family members as well as probing pocket depth (PPD) in active sites of AP patients, referred to department of periodontics, Faculty of Dentistry, Tehran University of Medical Sciences.
Materials and Methods: In this cross sectional, descriptive study, 54 sites (PPD> 5mm) in 15 patients were considered for culture. Marginal gingiva was dried and sampling performed by paperpoint (#30). The selective medium for Aa, was Trypticase Soy Agar-Bacitracin- Vancomycin (TSBV) and for Pg was Brucella agar.Results were analyzed using Fisher and Chi-Square statistical tests.
Results: Thirteen patients or 38 sites (70.4%) were identified as Aa positive and 3 patients or 10 sites (18.4%) were Pg positive. There was no significant relation between the presence of Aa and sex or age (P=0.086). Pg was more prevalent in men compared with women (P<0.0001) but with regard to age there was no statistical difference between men and women. Aa had a significant positive correlation with PPD (P=0.002), which was not true for Pg. In addition, the number of positive sites showed a significant negative correlation with the number of family members.
Conclusion: Based on the present study, the prevalence of Aa in deep pockets in patients with AP is higher than Pg.
H. Kermanshah , Mj. Kharazi Fard , H. Yesharim ,
Volume 18, Issue 1 (3-2005)
Abstract
Statement of Problem: Porcelain restorations are susceptible to fracture and a common method for repairing is the use of silane and composite on etched porcelain. Although HF is very effective in porcelain etching but has detrimental effects on tissues.
Purpose: In this study, the effect of APF and PHA was compared with HF in porcelain etching. Also the role of silane, unfilled resin and dentin bonding in bond strength of composite- porcelain was evaluated.
Methods and Materials: In this experimental in-vitro study, one-hundred twenty porcelain square blocks (552 mm) were prepared and bonding surfaces of each sandblasted. Samples were divided into three groups. The first group (n=40) were etched with buffered HF 9.5% (Ultradent) for 1 min., the second group (n=40) were etched with Iranian APF 1.23% (Kimia) for 10 minutes and the third group (n=40) were etched with Iranian PHA 37% (Kimia) for 1 min. Ultradent silane was applied on the surfaces of half of cases in each group. On the surfaces of half of silane-treated samples unfilled resin was applied and dentin bonding was used on the surfaces of the remaining. Samples without silane were treated in a similar manner. Composite cylinder with 4mm diameter and 2 mm height was bonded to porcelain. Specimens were stored in 37°C distilled water for 24 hours and subjected to 500 cycles. Shear bond strength was measured with an Instron machine and type of fracture was evaluated using a stereomicroscope. Results were analyzed using 3 way ANOVA, Kaplan- Maier and Tukey HSD tests.
Results: Findings showed that PHA and APF roughened the porcelain surface without creating retentive micro undercuts but HF etches porcelain and creates retentive microundercuts. Ultradent silane had no significant effect on bond strength of porcelain- composite. Unfilled resin with Ultradent silane compared with dentin bonding with the same silane is more effective in bond strength of composite- porcelain.
Conclusion: Based on present study, application of Ultradent silane on sandblasted and etched porcelain with PHA or APF cannot be used as an alternative to this silane on sandblasted and etched porcelain with HF.
Ar. Talaei Pour , S. Mehralizadeh , A. Mesgarzadeh ,
Volume 18, Issue 1 (3-2005)
Abstract
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
F. Sargolzaei , Ag. Sobhani , B. Nik-Nafs , Sha. Sarani , Gh. Sargazi , A. Sobhani ,
Volume 18, Issue 1 (3-2005)
Abstract
Statement of Problem: Several methods are used to enhance bone repair and new bone formation, and bone matrix gelatin (BMG) is recently introduced.
Purpose: The purpose of this histologic and histomorphometric study was to assess the osteogenic potential and the quantity of new trabecular bone formation after implantation of OCP and BMG alone and in combination into the cranial defects in rat.
Materials and Methods: In this experimental study, 100 young male Sprague Dawley rats (5-6 weeks age and 120-150gr weight) were divided into four groups randomly. A full thickness standard trephine defect 5mm in diameter was made in the rat’s parietal bone, and 5mg of OCP, BMG alone and in combination were implanted into the defects. No OCP and BMG particles were implanted in control group which was otherwise treated identically. On the 5th, 7th, 14th, 21st and 56th days after implantation, the rats were killed and bone samples collected. After processing the samples by routine histological procedures, 5µm thick sections of bone were cut and stained with Haematoxyline & Eosin (H&E) and Alcian Blue and studied histologically and histomorphometrically using light microscope and eyepiece graticule. The amount of newly formed bone was quantitatively measured by the use of histomorphometric methods. Data were analyzed with SAS statistical package using ANOVA and Duncan tests.
Results: In the experimental groups, the new bone formation was initiated from the margin of defects during 5-14 days after implantation. During 14-21 days after implantation, bone marrow cavities and bone marrow tissues in newly formed bone were seen. By the end of the study, the newly formed bone increased and was relatively matured and almost all of the implanted materials were absorbed. In control group, at the end of the study, a few clusters of new bone were seen near to the defect margins and host bone. The histomorphometric analysis indicated statistical significant differences in the amount of newly formed bone between the experimental and control groups (P<0.05).
Conclusion: Implants of OCP/BMG appear to stimulate bone induction and new bone growth in bone defects greater than the other groups and these biomaterials could be used in the repair of cranial bone defects in clinical situations.
J. Faryabi ,
Volume 18, Issue 2 (5-2005)
Abstract
Statement of Problem: Visual loss after traumatic injuries of the maxillofacial area is one of the worst complications of these injuries and if remains untreated will affect seriously the future life of patient.
Purpose: The aim of this study was to evaluate the frequency of blindness associated with midfacial fractures in Kerman Bahonar Hospital from 1996-2002.
Material and Methods: This descriptive study was done retrospectively on 207 patients with midface maxillofacial trauma admitted to Kerman Bahonar Hospital from 1996 to 2002.
Results: The frequency of unilateral blindness associated with midfacial trauma was 5.3 percent. The main etiologic factor was motor vehicle accidents (81.8%) and the most common area of fracture site of midface associated with blindness was Lefort III, Lefort II and NOE (Naso- Orbito- Ethmoidal) fractures.
Conclusion: The evaluated frequency of blindness after midfacial injuries in this study was similar to previous studies. The etiologic factors were different from those of developed countries and similar to developing ones.
Ah. Fakhraei , F. Jabal Ameli , G. Ghobadi ,
Volume 18, Issue 2 (5-2005)
Abstract
Statement of Problem: One of the most important complications after tooth extraction and oral and maxillofacial surgery is transient bacteraemia and prescription of prophylactic antibiotic is necessary to prevent postoperative infections in immunocompromised patients.
Purpose: The aim of this study was the evaluation of cephalexin and amoxicillin concentrations in dental alveolar sockets following tooth extraction.
Materials and Methods: In this interventional study, 80 healthy patients subjected to tooth extraction were divided into two groups. Each group received 1 gr amoxicillin or cephalexin and teeth were extracted 30-60-90-120-180 minutes after antibiotic intake. Blood sampling was performed immediately after extraction and concentrations of two antibiotics were measured in microbiology laboratory. ANOVA test and Post-hoc (Duncan) test were used for statistical analysis with P<0.05 as the limit of significance.
Results: The maximum serum concentration was 10.1006 μg/ml for amoxicillin at 120 minutes and 41.5467 μg/ml for cephalexin at 90 minutes after drug intake. The minimum inhibitory concentration (MIC) of cephalexin and amoxicillin for Streptococcus sanguis was 2 μg/ml and 1 μg/ml respectively.
Conclusion: The mean concentration for amoxicillin was 10 times and for cephalexin was 20 times higher than MIC.
F. Ezoddini Ardakani , D. Goodarzi Pour , M. Soltani Mohammadabady , ,
Volume 18, Issue 3 (5-2005)
Abstract
Background and Aim: Proper shaping and cleaning of the root canal system is one of the most important aspects of endodontic treatment. To estimate the canal length before instrumentation in endodontic treatment, traditionally, conventional radiographic techniques and recently Direct Digital Radiography (DDR) are applied. The application of computer technology to radiography has allowed less exposure time, image acquisition, manipulation, storage, retrieval, and transmission to remote sites in a digital format, elimination of wet processing and considerable reduction in the time lapse between image acquisition and display. The purpose of this study was to compare the accuracy of DDR versus conventional radiography in estimating endodontic file lengths of curved canals in first mandibular molars.
Materials and Methods: In this test evaluation study, fourty extracted human first mandibular molars with root curvature were selected.Samples were divided into two groups: With root curvature less than 25 and more than 25. Samples were mounted in plaster blocks and canal lengths were estimated by using DDR and conventional radiographs. Regression analysis and correlation coefficient were used to calculate statistical differences between the groups with P<0.05 as the limit of significance.
Results: Conventional radiography was more precise in canals with less than 25 degrees curvature (P=0.160). While, DDR was more precise for canals with curvature more than 25 degrees (P=0.605). However, these differences were not statistically significant.
Conclusion: The image quality of DDR system has improved to the point that it can now be used for estimating canal lengths, even for curved canals, with accuracy comparable to that of conventional radiography.
H Abdolsamadi , M. Hamian ,
Volume 18, Issue 4 (1-2006)
Abstract
Background and Aim: Geographic tongue (GT) is a relatively common lesion which is usually asymptomatic and found during routine examinations. Lesions may be single or multiple and frequently are confined to the dorsal surface and lateral borders of the tongue. Although the cause is unknown, zinc deficiency has been suggested as a possible etiologic factor. The purpose of the present study was to determine the therapeutic effect of zinc sulfate in patients with geographic tongue.
Materials and Methods: This study was a randomized double blind clinical trial performed on 40 cases. 20 patients in experimental group were given zinc sulfate and 20 patients in control group took placebo. Slides were taken at the first day and healing was recorded after 10 days. Data were analyzed using chi-square test with P<0.05 as the limit of significance.
Results: In 16 cases of the experimental group and in 3 cases of the control group signs of healing were observed.
Conclusion: Regarding the role of zinc in epithelial tissues health and development of filliform papillas and in spite of the positive effect of zinc sulfate in treatment of geographic tongue, further investigations concerning its effects on other mucosal conditions are recommended.
Z. Dalili , S. Rahro Taban , Ma. Vahedi ,
Volume 19, Issue 2 (5-2006)
Abstract
Background and Aim: Adenoids are normally large in children and their size starts to reduce during adolescence. Hypertrophic adenoids could be associated with allergic reactions. Enlarged adenoids result in nasal breathing difficulties and the child is forced to switch to mouth breathing. Airway obstruction causes postural alterations of jaw, tongue and head, and due to persistent obstruction, patient’s appearance changes to adenoid face. Evaluation of nasopharyngeal space in lateral cephalometic view is a simple and repeatable method for determination of the size and shape of adenoids and nasopharyngeal space which can provide a simple measurement of nasopharyngeal obstruction. The roof of nasopharyngeal space is covered by the sphenoid bone. Thus changes of nasorespiratory resistance by hypertrophic adenoids may affect the cranial base angles. In this study, the relationship between adenoid hypertrophy and cranial base angles was investigated.
Materials and Methods: In this descriptive-analytic study, lateral cephalometric views of 7 to 14 y/o patients from the files of orthodontic centers in Rasht city were selected. The radiographs with proper resolution were separated for this research. Adenoid to nasorespiratory ratio (A/N Ratio) was determined by Fujioka method and categorized in three groups: A (A/N 0.8), B (0.5
Sm. Razavi , A. Talebi , B. Movahedian Attar , I. Asgari ,
Volume 19, Issue 2 (5-2006)
Abstract
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.
