Showing 9 results for Behzad
Zafar Mahdavi Ezadi, Ezatolah Jalalian, Mohamad Hasan Salari, Shima Azimzad, Tahmine Safaie, Mahdi Shirazi, Behzad Salari,
Volume 26, Issue 4 (1-2014)
Abstract
Background and Aims : According to the common application of non-metal prefabricated posts in dentistry and lack of enough information about the stress distribution in the root canal walls by these posts, this study was performed to compare the effect of two simple taper and double taper posts on the stress distribution on root canal walls by photo elastic method .
Materials and Methods: The design of this study was experimental in photoelastic system. The posts, used in this investigation, were double taper and simple taper fiber posts with 0.9 mm diameter and 20 mm length and epoxy resin. First two photo elastic models with tooth dimensions were fabricated and the posts were placed inside the model. Then the core of the each post was fabricated on the model. Each models were loaded in polariscope and the formed fringe order colored ring were photographed.
Results: In 100 N, 90 degree angle loading in cervical and apical fringe order showed 2.50 and 1.39 in simple taper posts and 1.39 and 2.35 in double taper post. In 150 N, 30 degree angle loading in cervical and apical fringe order showed 4 and 2.65 in simple taper posts, and 4 and 2.5 in double taper post.
Conclusion: In the vertical and oblique loads, double taper fiber post showed better stress distribution than that of simple tapered posts.
Salari Behzad , Shahabi Sima , Bagheri Hossein , Yousefi Mahsa ,
Volume 26, Issue 4 (1-2014)
Abstract
Background and Aims : The aim of this study was to evaluate the effect of chlorhexidin 2%, sodium hypochlorite 2.5% and hydrogen peroxide 3% as three effective and regular disinfectants on the microleakage of 7th generation bonding agents in vitro.
Materials and Methods: 45 extracted molar teeth without carries were collected and disinfected. On buccal and lingual aspects of these teeth conventional class V cavity preparation were done (90 cavities), then randomly divided to 4 groups, three of them had 10 teeth (20 cavities) and one of them had 5 teeth (10 cavities) as control group. Cavities in each experimental group prepared with one of the disinfectants and then 7th generation bonding (Optibond all in one, kerr) was used as noted by manufacturer, then cavities filled with composite and polished. Bonding agent was used without our previous disinfectants manipulation in control group. Specimens were thermocycled with 1000 thermal cycles between 5 and 55 0 C each for 30 seconds and then immersed in the methylene blue 5%, then sectioned mesiodistally and investigated for microleakage under stereomicroscope (Olympus, Japan). Data were analyzed using Kruskal-Wallis and Wilcoxon mean rank tests.
Results: Despite the lower mean rank values for the untreated group at both occlusal and gingival aspects, the Kruskal-Wallis procedure (α=0.05) showed that the treatment factor did not significantly affect the mean rank values neither in occlusal (P=0.12) nor in gingival (P=0.39) part of cavities.
Conclusion: According to the results of this study, antimicrobial agents such as chlorhexidine 2%, sodium hypochloride 2.5% and hydrogen peroxide 3% can be used perior to 7th generation dentin bonding agent
(Optibond all in one, kerr) without much concern.
Sayed Mohamad Razavi, Behzad Zolfaghari, Bahareh Tahani, Mostafa Emami Doost, Mehrdad Forohande,
Volume 27, Issue 1 (4-2014)
Abstract
Background and Aims : Dentists have usually a critical role in diagnosing oral cancer lesions in their early stages. In this study we aimed to assess the senior dental student’ and dentists’ knowledge, attitude and behaviors regarding oral cancer in Isfahan.
Materials and Methods: A valid and reliable self-administered questionnaire was designed to assess the current practice, knowledge and attitude of general dentists working in Isfahan-Iran and senior dental students regarding oral cancer lesions. The questionnaire was consisted of questions to assess the knowledge and attitude regarding diagnosis, risk factors and prognosis of oropharyngeal cancerous lesions. The frequencies of answers to questions in sections of practice and attitude (just for dentists) and sum score of questions in knowledge section were calculated and compared using statistical analysis regarding age, sex, duration of experience and practice setting ) p ublic/private) of participants. Data were analyzed using ANOVA, chi-square, linear regression and logistic regression.
Results: 139 questionnaires from dentists and 57 questionnaires from students were returned. The mean score of dentists’ knowledge was 5.41 out of 13 (CI95%=5.03-7.79 ). Significant differences were observed among dentists regarding their experience (P=0.001). Only one fifth of the dentists in our survey reported to perform oral cancer examination for all of their patients in age of 40 and above and just about 34% of dentists gained acceptable level of knowledge. Among senior dental students, the status of knowledge was better as about 58% of them gained the level of acceptance (P=0.01).
Conclusion: Although dentists were willing to follow the diagnostic protocol for oral cancer, they were mostly unsatisfied with the level of their knowledge. Therefore, this study highlights the need for educational planning and training activities in general dentists with regard to the risk factors and early detection of oral cancers.
Goudarzipoor Dariush , Sowdagar Ahmad , Romoozi Elham , Xiavi Hesam Mikaili , Faal Behzad Sheykh ,
Volume 27, Issue 4 (1-2015)
Abstract
Background and Aims: In the panoramic images, palatoglossal space error develops when the patient is unable to put the tongue against the mouth roof. In the case of this error, the radiographic diagnosis of the area is made with some difficulties or ever the image may lose its diagnostic ability. The aim of the present study was to investigate the relationship between the palatoglossal space error of the panoramic images and skeletal relationship.
Materials and Methods: In this descriptive cross-sectional trial, 494 panoramic images were selected at the orthodontic department of Tehran dental school archive and the existence of the palatoglossal space was determined. The palatoglossal space error was statistically analyzed using chi-square test regarding the patients’ gender, age and skeletal relationships.
Results: Of total panoramic images, 346 (70.0%) cases showed palatoglossal space error while 148 (30.0%) images were free from this error. Furthermore, 74.1% of male images and 66.9% of female images showed palatoglossal space error. In Cl I (1˂ANB≤3), Cl II and Cl III patients 65.6%, 73.1% and 67.4% of the images demonstrated the error, respectively. The incidence of palatoglossal space error in 5-14 and 15 years old age or higher patients were 72.2% and 58.8%, respectively.
Conclusion: It was concluded that n o significant difference w as noted between the incidences of the palatoglossal space error regarding the patients’ gender or their skeletal relationships . T he error frequency was significantly decreased with age .
Shirazi Mohsen , Darvishpour Hojat , Nateghi Reza , Mirhashemi Amir Hosein , Salari Behzad ,
Volume 28, Issue 1 (5-2015)
Abstract
Tehran University of Medical Sciences, Tehran, Iran ( mirahashemi@tums.ac.ir )
Background and Aims: Nowadays patients refer to orthodontist for issue such as dental crowding and other aesthetic problems. The aims of this study were to evaluate the relationship between some of mandibular anatomical landmarks and dental crowding in the patient with skeletal Cl II due to mandibular deficiency.
Materials and Methods: 108 cases have been randomly selected out of patients with mandibular related Cl II problem associated with lower incisor crowding, out of orthodontic patient department of Tehran university of medical sciences. ANB, SNB, mandibular discrepancy, gonial angle, Sn-Go-Gn and IMPA was evaluated out of the data. Lateral cephalograms were used for this matter. The correlation between variables was evaluated by correlation test and after reviewing the data was analyzed using Normality test, the Pearson correlation coefficient was used for normally distributed variables.
Results: Corpus-ramus length ratio had a significant relationship with dental crowding (P≤0.05) but there was no meaningful and significant relationship between other facial landmarks ( P = 0.26 ).
Conclusion: there seems to be a slight relationship between facial landmarks and dental crowding in lower incisors. But further case control and clinical studies may be helpful in achieving more reliable data.
Shamsolmoulouk Najafi, Reza Yazdani, Behzad Salari, Homa Forouhesh Tehrani, Mohammad Javad Kharrazi Fard,
Volume 29, Issue 2 (11-2016)
Abstract
Background and Aims: The aim of this study was to investigate the effects of sodium bicarbonate against candida albicans, the main infectious factor of denture stomatitis, and to compare it with other common anti-candida medications.
Materials and Methods: Three concentrations of Candida albicans (105, 106, 107 CFU/mL) were prepared. Experimental substances were 5% sodium bicarbonate, nystatin, chlorhexidine, and sterile saline (as control). Each of them was added separately to the same amounts of Candida albicans of different concentrations, and sampled at the intervals of 1, 2, 3 and 4 min. Then, the samples were cultured and incubated. The number of formed colonies was counted for each plate. The data were analyzed, using ANOVA and Tukey test.
Results: Sodium bicarbonate showed a noticeable anti-candida effect on the concentrations of 105 and 106 CFU/mL, with almost similar anti-candida effect as nystatin and chlorehexidine(P=0.29, P=0.32). Nystatin was the most effective medication on the concentration of 107 CFU/mL of candida (P=0.03, P=0.01). Sodium bicarbonate and chlorhexidine were less effective in this concentration with no statistically significant difference (P=1.00).
Conclusion: Sodium bicarbonate showed a significant anti-candida effect at low and medium concentrations of Candida albicans, but nystatin was more effective in the higher concentrations.
Mohsen Shirazi, Armina Mellat, Behzad Salari,
Volume 29, Issue 3 (10-2016)
Abstract
Background and Aims: In the field of orthodontics, gaining comprehensive information around dento-skeletal complex is necessary to choose the best treatment plan for each patient. The aim of this study was to investigate the linear and angular parameters in panoramic radiographs to find a path to correlate transvers to sagittal dimensions.
Materials and Methods: Total number of sixty two, 8-14 years old children who sought for orthodontic therapy were selected (32 skeletal Class III and 30 skeletal Class I). They were exposed to x-ray to obtain the panoramic and lateral views in a controlled condition. Various linear and angular parameters were measured after tracing the landmarks on the panoramic radiograph. Data were obtained and analyzed using T-test. The level of significance was set at 0.05 (P<0.05).
Results: Linear parameters of Co-Co, Go-Go and PTM-PTM were significantly lower in class III patients than class I ones (P=0.04, 0.04, 0.02, respectively). The ramus width value was also lower in class III patients. Angular parameters of Me˄ and N˄ also showed the same results (P<0.001). Go˄ angle was significantly lower in the class I than class III patients (P=0.002, 0.007).
Conclusion: Some traceable linear and angular parameters were found in the panoramic radiographs which had the potential to correlate the transverse with sagittal dimension.
Farzane Jabari, Behzad Houshmand, Saeed Hesaraki,
Volume 31, Issue 3 (11-2018)
Abstract
The Guided Bone Regeneration (GBR) treatment concept advocates that regeneration of osseous defects is predictably attainable via the application of occlusive membranes, which mechanically exclude non-osteogenic cell populations from the surrounding soft tissues, thereby allowing osteogenic cell populations originating from the parent bone to inhabit the osseous wound. The use of membrane to exclude non-osteogenic cells, is a key principle of guided bone regeneration. A large number of membranes have been evaluated in clinical and experimental studies. The object of this study was to review the literature regarding guided bone regeneration and all types of membranes that were used in this technique. 72 articles between the years 1968 through the 2016 from PubMed, Medline and Google Scholar using the related keywords, were selected. Finally, we concluded that the modification of mechanical and physico-chemical properties of membranes could improve the process of new bone growth. However, determination of the exact role of membrane porosity in this process, still needs to be clarified. Optimization the chemical composition of membrane with the focus and attention to obstructive property and bioactivity, is an important point in this research field. Various factors such as flexibility, mechanical strength and degradation rate determine the type of membrane used for bone tissue regeneration.
Mohsen Shirazi, Shiva Shadmand, Behzad Salari,
Volume 32, Issue 4 (1-2020)
Abstract
Background and Aims: Nasal obstruction is a common condition among children, in which delaying treatment can stabilize its negative effects on dentoalveolar structures during adulthood. In this study we aimed to investigate the effect of total nasal obstruction on the craniofacial structures of rabbits.
Materials and Methods: In this animal study, total numbers of 44 rabbits with high genetic proximity were selected. Several metal implants were inserted in the anatomic landmarks of their skulls and then underwent three different types of x-ray exposure (lateral, posterior-anterior and occlusal views). Half of them underwent surgically assisted total nasal obstruction, and the other half were considered as control group. All rabbits were kept in the same environment up to maturation period. Then, they underwent the same x-ray exposures. The primary and final radiographs were traced and various linear and angular were compared between them.
Results: The anterior facial height (P=0.01), maxillary depth (P=0.005), articular angle (P=0.005), maxillary and mandibular plan angle were significantly more in the rabbits with total nasal obstruction. However, the interdental width (P=0.005), maxillary perimeter (P=0.005), nasopharyngeal width (P=0.01) and maxillary and mandibular width were significantly less in them. The skull base length (P=0.30), gonial angle (P=0.40), and maxillary length (P=0.10) were not significantly different between the two groups.
Conclusion: Total nasal obstruction had various impacts on the craniofacial structures.
