Showing 10 results for Bagheri
Tahereh Sadat Jafarzadeh Kashi, Mohammad Erfan, Akbar Fazel Najafabadi, Seied Mostafa Fatemi, Marjan Behroozibakhsh, Haleh Hali, Hosein Bagheri Gorgani,
Volume 25, Issue 2 (9 2012)
Abstract
Background and Aims: The aim of this study was to measure the degree of conversion (DC) of three types of composite resins (micro-hybrid, nano-hybrid and Ormocer) with different light curing units (LED LCU and QTH LCU) in two depths.
Materials and Methods: Three commercially available dental resin composites were used in this study: (Tetric Ceram, Ivoclar Vivadent, Liechtenstein-A2 shade), (Tetric Evoceram, Ivoclar Vivadent, Liechtenstein-A2 shade), (Ceram X, Dentsply, Germany-M2 shade). Specimens were divided into two groups, 5 specimens were photo-activated by QTH unit (Coltolux 75-Colten) and the other five specimens were cured by LED (Demi-Kerr). Then each specimen was sectioned at the top surface and at 2-mm depth. The DC was measured by FT-IR
(Bruker-tensor 27). The data were analyzed by 3-way ANOVA test.
Results: There was significant difference between tested composite resins (P<0.001). The results of top surfaces were significantly different from those observed at 2-mm depth (P<0.001). The type of curing unit affected the polymerization of Ceram X resin composite.
Conclusion: This study showed a significant difference in the degree of conversion in different thicknesses within three groups of resin composites.
Fateme Nematollahi, Nasim Azizi, Sima Shahabi, Loghman Ghahremani, Zohre Asgari, Hossein Bagheri ,
Volume 26, Issue 2 (5-2013)
Abstract
Background and Aims: Failure of bonding between artificial teeth and denture base material is a considerable problem for patients who wear dentures. According to the different impact of artificial teeth and different information about resistance force of mastication and also with deficiency in researchs, this study was designed to compare the bond strength of composite and acrylic artificial teeth to auto-polymerized denture base resins with and without cyclic loading.
Materials and Methods: In this experimental and in vitro study, an acrylic resin auto-polymerized (Rapid Repair, Dentsply) and four artificial teeth (Acrylic Marjan new, Composite Glamour teeth and Ivoclar acrylic and composite teeth) were used. Therefore, 8 groups of 10 specimens each were evaluated. All specimens were thermocycled for 5000 cycles, in water baths between 5 and 55 ◦ C. Half the specimens in each group were treated with cyclic loading at 50N for 14, 400 cycles at 1.2 Hz. The shear bond strengths were measured using a Universal Testing Machine. Data were analyzed using Two-way ANOVA test.
Results: Statistical analysis demonstrated no significant effect of cyclic loading on the shear bond strength, but the type of artificial tooth affected the shear bond strength (P=0.006). Also, the interaction between Cyclic loading and the type of artificial tooth showed no significant difference (P=0.98). Tukey test showed that acrylic teeth (Ivoclar) had statistically higher bond strength values than that of other teeth (PGlamour=0.02), (PComposite ivoclar=0.01) and (PMarjan new=0.02).
Conclusion: Within the limitation of this study, the predominant type of fracture in all groups was cohesive, therefore the bond strength was adequate in all teeth and the type of artificial tooth may influence the bond strength of denture teeth to denture base resin. Cyclic loading had no significant effect on the bond strength of denture teeth to the auto-polymerized acrylic resin.
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 Mohsen Hosseini, Fateme Bagheri, Faranak Farahmand, Asiye Heydari, Elahe Khorasani,
Volume 29, Issue 4 (1-2017)
Abstract
Background and Aims: Nowadays, oral cancer is considered one of the most important diseases related to oral health. The objective of the present study was to determine the dental students’ knowledge in Isfahan about oral cancer and the comparison of the level of students' knowledge in different years of education.
Materials and Methods: The present study was a cross-sectional-analytical one conducted in 2013. The population of study included the dental students of private and state University of Isfahan which 255 students were randomly selected. The data were collected using questionnaire and were then analyzed using SPSS software program and Kruskal-Wallis and Mann-Whitney.
Results: From private and public dental schools in Isfahan, 56% and 44% of dental students were involved. Regarding performing routine clinical oral examination, 81% of the participants answered positively, which showed no significant difference among the years of education of the participants (P=0.116). Regarding the examination of patients with oral lesions, 46% of them answered positively, which the difference between the years of education was highly significant (P≤0.001).
Conclusion: The findings of the research indicated that the level of knowledge of dental students of Isfahan city regarding the detection of oral lesions was not sufficient. Although, the students did not perform common examinations for exploring oral cancer, they did not have sufficient knowledge regarding some of the risk factors and oral lesions related to cancer. Therefore, it is necessary that a comprehensive curriculum be developed in this regard for their education.
Kimia Negahdari, Maryam Sadat Tavanagar, Rafaat Bagheri,
Volume 30, Issue 4 (1-2018)
Abstract
Background and Aims: Microhardness, sorption, and solubility are useful predictors of a resin composite’s clinical success. This study aimed to evaluate the effect of 60 days of water storage on the microhardness, sorption, and solubility of 3 commercial nanohybrid resin composites.
Materials and Methods: Three nanohybrid composites were evaluated: GC Kalore (GC), Aura (SDI), and G-ænial Universal Flo Universal Flo (GC). Ten disc-shaped samples were prepared for each material. After baseline weight measurement, the specimens were stored in distilled water for a period of 60 days, and then in desiccators for another 60 days. Specimens were weighed at 24 hours, 7 and 60 days of water storage and desiccation. For the microhardness test, 24 were prepared for each material and divided into 6 groups based on storage media (dry and wet) and storage time (24 hours, 7 days, and 60 days). Specimens were tested by a digital Vickers microhardness tester after storage and data were analyzed using SPSS software.
Results: G-ænial Universal Flo Universal Flo showed the highest sorption and solubility and the lowest microhardness after 60 days of water storage. GC Kalore showed lower sorption and solubility compared to Aura. Also GC Kalore had higher microhardness than Aura after 60 days of storage in water, while Aura had higher microhardness in dry storage.
Conclusion: Composites with lower sorption and solubility showed higher microhardnss in wet conditions. Flowable composite resin showed the lowest microhardness and the highest sorption and solubility values. Therefore, the negative effect of water sorption and solubility on Surface microhardness should be considered in clinical decisions.
Seyyede Fateme Basri, Rafat Bagheri, Maryam Sadat Tavangar,
Volume 31, Issue 1 (6-2018)
Abstract
Background and Aims: Fracture and color change are among the most common causes of clinical failure of resin composite restorations. Therefore, this study aimed to examine the fracture toughness and color changes of 3 Nano-hybrid resin composites in dry and wet conditions.
Materials and Methods: Three resin composites were studied. A total of 36 rectangular specimens were prepared for each material, randomly divided into 2 groups, and stored at 37°C dry or soaked in distilled water. In each group, the specimens were subdivided into three groups (n=6) and stored for 1, 7, and 60 days. After each time interval, the specimens were tested for the fracture toughness and loaded at a cross-head speed of 0.5mm/min using a universal testing machine. The baseline and final color measurement was recorded for each specimen using a spectrophotometer. The collected data was analyzed using ANOVA and Kruskal-Wallis tests.
Results: After 60 days, the mean value of fracture toughness was lower in the wet condition compared to that of dry condition. However, it was not significantly different except for aura Bulkfil (P=0.001). Color change was significantly different for Tetric Evoceram and aura with a greater value in the wet condition compared to that of dry (P=0.004). The greatest color stability was found for aura and the least for Tetric Evoceram.
Conclusion: In this study, most of the materials stored in a dry condition showed a greater fracture toughness and color change.
Dana Jafarpur, Rafaat Bagheri,
Volume 31, Issue 4 (1-2019)
Abstract
Background and Aims: Glass ionomer cements are among direct restorative materials which are used in an environment saturated with moisture. Therefore, having the ability to prevent water contamination is crucial. The aim of this study was to determine the water sorption and solubility of five glass ionomer restoratives with and without two nanofilled resin coating agents.
Materials and Methods: Five glass ionomer cements (Fuji BULK/GC, EQUIA Forte Fil/GC, Fuji II LC/GC, riva self cure/SDI, riva light cure/SDI) and two resin-based coating (G-COAT PLUS/GC and EQUIA Forte Coat/GC) were used in this study. Water sorption and solubility were measured in accordance with the ISO 4049's. For each material, 15 disc-shaped specimens were prepared using a polyethelyn mould. The specimens of each material were randomly divided into two groups: 10 coated and 5 uncoated. For the coated groups of each material, 5 specimens were coated with G-COAT PLUS, and 5 with EQUIA Forte Coat. Data were analyzed using SPSS software version 18 (SPSS Inc., Chicago, IL, USA). Two-way ANOVA was applied to investigate if there were any interactions between materials and coatings. One-way ANOVA was used to compare different variables between the materials, and post-hoc Tukey’s test was performed to show significant differences in subgroup comparisons.
Results: A significant interaction effect was obsevred between materials and coatings (P<0.05) using two-way ANOVA. The uncoated groups showed higher mean sorption and solubility values compared to the coated groups, and the groups coated by G-COAT PLUS showed less mean sorption and solubility values than that of EQUIA Forte Coat. In general, the lowest mean sorption and solubility values among glass ionomer cements belonged to Fuji BULK.
Conclusion: The water sorption and solubility values of glass ionomer cements could be reduced by the use of a protective coating.
Hamid Mahmoodhashemi, Abbas Karimi, Parisa Bagheri, Narges Hajiani,
Volume 32, Issue 2 (10-2019)
Abstract
Background and Aims: Management of an emergency is ultimately the dentist’s responsibility. Therefore, the dentists need to be able to manage an emergency and perform Cardiopulmonary Resuscitation (CPR) if necessary. The present study was undertaken to assess the knowledge of final-year dental students in Tehran regarding CPR.
Materials and Methods: In a cross-sectional study, 200 final-year dental students (44 males and 156 females) from 4 dental schools in Tehran were randomly selected and surveyed using a multiple choice questionnaire evaluating their knowledge about CPR. The data were analyzed by SPSS16 software using two descriptive and inferential statistical methods via chart drawing of statistical quantities calculation and analysis of variance.
Results: The mean score was 5.43±2.43. A positive correlation was found between receiving practical training and level of knowledge (P=0.001). However, the results showed no statistical differences between sex (P=0.409) or various dental schools (P=0.089).
Conclusion: Since, the level of knowledge about CPR among participants were poor, there is a perceived need for further training in dental schools.
Md Mahdi Kashani Aragh Bidi, Dr Mahdi Jabari Jahromi, Dr Sepide Bagheri Hosein Abadi, Dr Mohammadreza Shokuhifar,
Volume 33, Issue 1 (7-2020)
Abstract
Background and Aims: The vertical growth pattern of the face depends on several factors. One of these factors can be the muscle strength of the jaw. Maximum occlusal force (MOF) can be considered as an index to measure the function of the muscles of the masticatory system. Despite the various studies, the relationship between the facial pattern and muscle function is still controversial. According to soft tissue paradigm theory, muscle can affect the shape and form of bones of the jaw, face and head. The aim of this study was to determine the relationship between the maximum occlusal force and head and face growth pattern in dental students of Shahed University in Tehran.
Materials and Methods81 dental students (40 males and 41 females) were participated. MOF was measured with a loadcell designed for this purpose, and the anthropometric points of the face and head were measured with digital caliper. Two-way ANOVA and Tukey HSD tests were used to determine the effect of facial and head patterns on the maximum occlusal force. Statistical analysis was performed by SPSS23.
Results: The mean MOF in males was 480 N and in females 320 N. Head forms in our sample research were 54.32% Brachycephale, 32.09% Mesocephale, and 13.58% Dolicocephale. The form of the face was 23.45% euprosopic, 39.5% mesoprosopic, and 37.03% leptoprosopic. According to the statistical analysis, the relationship between the maximum occlusal force and leptoprosopic form of face was statistically significant (P=0.02). However, there was not significant relationship between the maximal occlusal force and none of the three type of head forms (P=0.813).
Conclusion: MOF was related to the leptoprosopic pattern of face, and these individuals had less bite power. No relationship between the maximum occlusal force and head forms and neither between the head pattern and facial pattern was found in this study. The maximum occlusal force in men was higher in all three facial patterns than that of women, although this relationship was not significant.
Mohammad Hossein Ronaghi, Atefeh Bagheri,
Volume 36, Issue 0 (5-2023)
Abstract
Background and Aims: Artificial intelligence (AI) technology is widely used in dentistry in addition to numerous other sectors that impact human life, including medicine. A dentist can use AI technology to analyze patient data, diagnostic processes, and management activities. This study was conducted in Iran to identify the dental applications of AI and prioritize them.
Materials and Methods: In the winter of 2022, this applied research was carried out in two stages using a mixed method. In the qualitative phase, 570 articles from 2011 to 2022 were identified in the databases of PubMed, Web of Science, Scopus and Google Scholar among the studies in the field of dentistry and related to artificial intelligence technology based on keywords and then the applications of artificial intelligence in dentistry were extracted. In the quantitative phase, the identified applications prioritized by a group of experts comprised 13 University faculty members with related research areas using the best-worst method (BWM).
Results: The factors identified in the first stage of research were classified into six categories: implant and surgery, executive management, disease diagnosis, analysis of images, clinical prediction, and orthodontics. According to the experts’ opinion, it was determined that medical photo analysis had the highest coefficient of importance (0.252) followed by orthodontics (0.234), disease diagnosis (0.151), implantology and surgery (0.143), clinical forecasts (0.127), and executive management (0.093).
Conclusion: Dentists can use the capabilities of artificial intelligence in examining patients' teeth and diagnostic tests in dentistry based on the analysis of patient information. Information technology policymakers with the support and reinforcement of knowledge-based companies active in the field of artificial intelligence and joint investment in the field of medicine can be the basis for progress and the development of this technology in the country and the field of treatment.
