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Showing 7 results for Memarian
Selection of six anterior teeth for edentulous patients
M. Memarian , R. Masoomi ,
Volume 17, Issue 4 (7 2005)
Abstract

Statement of Problem: Choosing an appropriate tooth for edentulous patients is a very important step in dentistry.
Purpose: This research has been done for determination of proper procedure for tooth selection in edentulous patients.
Methods and Materials: In this cross- sectional study 100 student and people who have come to a medical
center (range 20-30 years old) were collected randomly and the size of their anterior teeth were determined. A gauge with 0.01 mm accuracy and flexible plastic millimeter was used in order for measurement of anatomic landmark. For achieving the relation between the sizes of teeth statistical analysis was done.

Results: 50% of patients were female and the other 50% were male. We found a relationship between mesiodistal width of six maxillary anterior teeth and mesiodistal width of six mandibuMary teeth that can be shown as follow In men: six mandibular anterior teeth width= 0.S3 * width of six maxillary anterior teeth -2.008 In women: six mandibular anterior teeth width- 0.56 * width of six maxillary anterior teeth + 9.53 Also strong meaningful relationships between width of six anterior maxillary teeth and the width between corners of the lip in curve position have been noticed only in men which can be show' as follow:width of Six mandibular anterior tceth= 39.63 + 0.21+ the width between corners of lip in curve position for men
Conclusion: Although there are different ways for prediction of teeth size, it seems these findings can be
helpful in determining and prediction of it.


Microbial evaluation of dental units waterlines at the department of operative dentistry, Tehran university of medical sciences in the year 2006
M. Memarian, Mr. Fazeli, H. Jamalifar, S. Karami,
Volume 21, Issue 1 (14 2008)
Abstract

Background and Aim: According to infection possibility in high risk patients, assessment of microbial contamination in water sources utilized at medico-dental units has become a recent concern. The purpose of this study was to evaluate the microbial contamination in dental units waterlines at the department of operative dentistry, Tehran university of medical sciences in the year 2006.

Materials and Methods: In this cross-sectional study, six dental units in the department of operative dentistry were selected to assess microbial contamination in water sources. Samples were taken on Saturdays (the first working day in a week) and in the midweek, 64 and 16 hours respectively after turning the units off. Moreover, for investigating the effect of flushing, sampling was done at 30, 60, 90 and 120 seconds after flushing and were taken from three parts of each unit including air/water syringe, turbine handpiece and also cup filler water. Samples were transported in closed sterile containers to microbiology laboratory of the school pharmacy. Data were analyzed by Kruskal-Wallis and Dunn tests with p<0.05 as the level of significance.

Results: E.coli was isolated from contaminated samples. Contamination decreased by flushing. In midweek after 90 seconds flushing, water contamination disappeared. On Saturdays 2 minutes flushing decreased contamination to lower that 200 cfu/ml (the rate recommended by ADA). Samples taken from turbine handpieces showed significantly higher contamination rate compared to air/water syringe and cup filler water (p<0.001).

Conclusion: According to the results of this study, dental units waterlines showed bacterial contamination which was eliminated after 120 seconds of flushing.


colorimetric evaluation of Cercon zirconia and metal ceramic restorations in two thicknesses of veneering porcelain
H. Dorriz, M. Memarian, A. Madani, L. Sedighpor, Ar. Shamshiri,
Volume 24, Issue 1 (23 2011)
Abstract

Background and Aims: The aim of this study was to evaluate the effect of zirconia and base metal cores on the color of restorations. Furthermore, the effect of different backings on the color of cercon zirconia was evaluated.
Materials and Methods: The specimens were Cercon zirconia and metal ceramic discs with "high Au" and "base metal" alloys. Cercon zirconia discs were veneered with veneering shade of A2 and two thickness of porcelain (0.7 mm, 1.2 mm). There were 3 discs in each group. Metal ceramic discs were made of "nickel-chromium" alloy (Verobond) and "high Au" alloy (World 89) and two shades (A2, A3.5) and two thicknesses of veneering porcelain. 3 types of backing (high Au, nickel-chromium and A3 shade composite) were made for Cercon zirconia discs. Spectrophotometric evaluation of zirconia discs (on 3 backings) and metal ceramic discs was done. One-way ANOVA and Tukey tests were used for data analysis.
Results: There were no significant differences between the amounts of L*, a*, b* for Cercon zirconia on different backings (P>0.05). In comparison between different core groups, a* was significantly higher in metal ceramic groups compared with that of zirconia groups (P<0.05).
Conclusion: Cercon zirconia can completely mask the underlying backing.


Comparative evaluation of pH, bond strength and washability in four common denture adhesives in Iran
Mehran Bahrami, Maryam Memarian, Farinaz Khodadad Kashi,
Volume 28, Issue 3 (10-2015)
Abstract

Background and Aims: Residual ridge resorption is an unpredictable, unavoidable and time-dependent process which occurs in denture-wearing patients especially those who use mandibular dentures. This process causes more problems in mandible because of its less support, tongue forces and more resorption. Inserting implants in many of these patients requires bone grafts. Overdentures are also more expensive. Denture adhesives are the last option to improve retention and masticatory function in denture-wearers with severe resorption of alveolar ridge. Nowadays only a few denture adhesives are used in Iran and there is not much information about their standard features including, pH, bond strength and washability. The objective of this study was to examine and compare the mentioned characteristics of four denture adhesives (Professional, Corega, Fittydent and Fixodent) and to introduce the most suitable denture adhesive for clinical use.

Materials and Methods: All the methodologies of ISO 10873:2010 were applied. To measure the pH value, 1±0.1g of each denture adhesive was diluted with 5g of propylene glycol and mixed with water. Using pH meter, pH of each group was measured separately for 4 times (n=4) and results were recorded. For the washability test, 4 dentures were fabricated (n=4) and each group of denture adhesives was placed on a denture according to manufacture instructions. For simulating mouth environment specimens were placed in water at 37±2 ̊C bath for 1 hour and then washed with a plastic brush. Specimens were examined for any residual adhesive and the results were recorded. For bond strength test, a sample holder was gently filled with denture adhesives and was attached to the holding arm of bond strength testing device (Santam, STM 20, Iran). Specimens were placed in 300ml water bath at 37±2 ̊C for 10 minutes, and then shaken to be dried and placed in the bond strength testing device. 10N force with 5mm/min rate was applied to the specimen. The force was maintained for 30s and then device arm was pulled back and the highest number was recorded with computer software (Santam Machine Controller v4.19, Iran). The test performed 8 times (n=8) for each adhesive and 8 results were recorded. Data were analyzed using ANOVA test for comparing the bond strength with a significant level fixed
at 0.05.

Results: Professional and Corega adhesives had more neutral pH than that of Fittydent and Fixodent which were more acidic. Washability test showed no remaining mass of any adhesive and there was not any statistically significant difference between groups (P>0.05). Fittydent and Corega adhesives showed higher bond strength than that of Professional and Fixodent and this difference was statistically significant (P<0.05).

Conclusion: Professional and Corega adhesives had less acidity. Thus they cause less harmful effects on the oral mucosa than that of Fittydent and Fixodent and should be indicated in patients with little-tolerant oral mucousa such as diabetous, iron-deficiency anemia and hypertention. All the groups had acceptable washability. Fittydent and Corega had higher bond strength than that of Professional and Fixodent. Therefore in complete-denture-wearers who require more retention as a result of severe ridge resorption, macrotruma, and maladaptiivity, Fittydent and Corega seems to be more acceptable.


Evaluation of torque loss in Co-Cr castable abutments after cyclic loading
Somayeh Zeighami, Marzieh Alikhasi, Maryam Memarian, Moeen Hosseini Shirazi,
Volume 30, Issue 4 (1-2018)
Abstract
Background and Aims: For the clinical success of implant-retained prostheses, fitness of matching components and stability of the applied torque to the implant-abutment assembly under dynamic occlusal loading is essential. The aim of this study was to evaluate the torque loss in Co-Cr castable abutments after cyclic loading.
Materials and Methods: 10 castable abutments were cast in Co-Cr alloy with similar size and height. Each specimen was mounted vertically on a separated implant using a 30 Ncm tightening torque. The detorque values of the abutments were evaluated after 10 min. The same tightening torque was applied to the abutments on their corresponding implants and cyclic loading was applied for 500,000 cycles to the implant-abutment assembly. The torque values after cyclic loading were recorded for each specimen. T-test analysis was conducted on scores from the groups.
Resultes: The results of this study showed that the percentage of torque loss in castable abutments was significantly increased after cyclic loading (P<0.001).
Conclusion: Misfit between the castable implant components can cause torque loss before and after cyclic loading. However, it is more appropriate to relate the results of this study to the screw loosening of the above mentioned abutments than judging their clinical performance.

Survey of dentist’s professional appearances from patients’ point of view at Tehran University of Medical Sciences
Mehran Bahrami, Maryam Memarian, Hossein Tamaddon, Mohammad Javad Kharrzi Fard,
Volume 31, Issue 2 (9-2018)
Abstract
Background and Aims: The dentist's attire and appearance affects his/her relationships with the patients. It is also essential to sync the professional attire in dentistry with the habits and Islamic culture of Islamic Republic of Iran, meet the patients' desires, and pay attention to the infection-control-requirements as well.The objective of the present study was to determine the patients' viewpoints about the professional appearance of the dentists at Tehran University of Medical Sciences, Dental School in 1395-96.
Materials and Methods: In this descriptive cross-sectional study, 103 patients (54 females and 49 males) were studied. (=α0.05 and standard variation=4.5). The questionnaire were included color photographies of a female dentist and a male dentist dressed in different attires. The patients were asked to select the cleanest, and the most trustable, competent, and experienced dentist according to the 4 different attires. The frequencies and percentages of the participants’ answers to the questionaire were descriptively reported.
Results: All patients preferred dentists to use white coat during their treatment. For the male dentists, most patients (45.6%) favored simple hair model. For the female dentists, most patients (35.9%) considered veil as the more acceptable Hejaband, and 54.4% of them preferred light makeup.
Conclusion: All patients preferred their dentists to dress in the professional attire with a white coat. They believed that wearing formal-professional-dressing by the dentists may show them look cleaner, and more trustable, more competent, and experienced.

Designing and comparing psychometric properties of the checklist for clinical skills assessment of dental students in complete denture course and evaluation of raters’ and students’ satisfaction
Shiva Shirazian, Sakineh Nikzad Jamnani, Maryam Memarian, Homa Shaghi,
Volume 33, Issue 1 (7-2020)
Abstract
Background and Aims: Due to the very high importance of assessing the clinical performance of students, choosing the best assessment tool and method is one of the most important goals and tasks in medical education. The objective of this study was the development of a checklist for the assessment of dental students’ clinical skills of Tehran University of Medical Sciences, in the clinical complete denture course. The second aim was to determine the validity and reliability of the checklist, and The third aim was the evaluation of raters’ and students’ satisfaction.
Materials and Methods: The checklist was developed in expert panel sessions, and the validity and reliability of the checklist were assessed with CVI (content validity index) test-retest and inter-rater reliability methods, respectively. Students (n=15) were evaluated with a developed checklist. At the end of the session, the satisfaction level of staff and students were assessed. The obtained information was reported descriptively with the expression of mean and standard deviation and in the form of relative and absolute frequencies.
Results: The content validity index (CVI) of the checklist was 0.96. The reliability of the checklist confirmed with a high Intraclass Correlation Coefficient (>0.8) (between 0.82-0.97) (P<0.05). The coefficient of agreement in inter-rater reliability was 0.99 (between 0.991-0.998). Raters’ and students’ satisfaction earned a high percentage of satisfaction.
Conclusion: The designed checklist has the optimal features of a good students’ clinical performance assessment tool; it seems that using this checklist can be an excellent alternative method to a global rating scale to assess the clinical skills of dental students in the complete denture courses.

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