Kamal Asgar Research Center

Shīrāz, Iran

Kamal Asgar Research Center

Shīrāz, Iran
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Saghiri M.-A.,University of Tehran | Garcia-Godoy F.,University of Tennessee Health Science Center | Asatourian A.,Kamal Asgar Research Center | Lotfi M.,Tabriz University of Medical Sciences | And 2 more authors.
Medicina Oral, Patologia Oral y Cirugia Bucal | Year: 2013

Objectives: Recently, it was shown that NanoMTA improved the setting time and promoted a better hydration process which prevents washout and the dislodgment of this novel biomaterial in comparison with WTMA. This study analyzed the compressive strength of ProRoot WMTA (Dentsply), a NanoWMTA (Kamal Asgar Research Center), and Bioaggregate (Innovative Bioceramix) after its exposure to a range of environmental pH conditions during hydration. Study Design: After mixing the cements under aseptic condition and based on the manufacturers recommendations, the cements were condensed with moderate force using plugger into 9 × 6 mm split molds. Each type of cement was then randomly divided into three groups (n=10). Specimens were exposed to environments with pH values of 4.4, 7.4, or 10.4 for 3 days. Cement pellets were compressed by using an Instron testing machine. Values were recorded and compared. Data were analyzed by using one-way analysis of variance and a post hoc Tukey's test. Results: After 3 days, the samples were solid when probed with an explorer before removing them from the molds. The greatest mean compressive strength 133.19±11.14 MPa was observed after exposure to a pH value of 10.4 for NanoWMTA. The values decreased to 111.41±8.26 MPa after exposure to a pH value of 4.4. Increasing of pH had a significant effect on the compressive strength of the groups (p<0.001). The mean compressive strength for the NanoWMTA was statistically higher than for ProRoot WMTA and Bioaggregate (p<0.001). Moreover, increasing of pH values had a significant effect on compressive strength of the experimental groups (p<0.001). Conclusion: The compressive strength of NanoWMTA was significantly higher than WMTA and Bioaggregate; the more acidic the environmental pH, the lower was the compressive strength. © Medicina Oral S. L. C.I.F.


Saghiri M.A.,University of Tehran | Nazari A.,Tokyo Medical and Dental University | Garcia-Godoy F.,University of Memphis | Asatourian A.,Kamal Asgar Research Center | Malekzadeh M.,Islamic Azad University at Tehran
Microscopy and Microanalysis | Year: 2013

This study evaluated the effects of nanoindentation on the surface of white mineral trioxide aggregate (WMTA), Bioaggregate and Nano WMTA cements. Cements were mixed according to the manufacturer directions, condensed inside glass tubes, and randomly divided into three groups (n = 8). Specimens were soaked in synthetic tissue fluid (pH = 7.4) and incubated for 3 days. Cement pellets were subjected to nanoindentation tests and observed by scanning electron microscopy. Then, the images were processed and the number of cracks and total surface area of defects on the surface were calculated and analyzed using ImageJ. Data were submitted to one-way analysis of variance and a post hoc Tukey's test. The lowest number of cracks and total surface of defects were detected in Nano WMTA samples; however, it was not significantly different from WMTA samples (p = 0.588), while the highest values were noticed in Bioaggregate specimens that were significantly different from Nano WMTA and WMTA (p = 0.0001). The surface of WMTA and Nano WMTA showed more resistance after exposure to nano-compressive forces which indicated a better surface tolerance against these forces and crack formation. This suggests these substances are more tolerant cement materials which can predictably withstand loaded situations in a clinical scenario. Copyright © 2013 Microscopy Society of America.


Saghiri M.A.,Islamic Azad University at Tehran | Saghiri M.A.,Kamal Asgar Research Center | Garcia-Godoy F.,University of Memphis | Lotfi M.,Tabriz University of Medical Sciences | And 2 more authors.
Photomedicine and Laser Surgery | Year: 2012

Objective: The aim of this in vitro study was to evaluate The effects of diode laser, MTAD ™ and laser plus MTAD on The push-out bond strength of mineral trioxide aggregate (MTA)-dentin. Background data: MTA has been used widely, especially in root canal therapies (RCT); however, The effect of different final treatments during RCT has been questioned regarding The retention characteristic of this cement-based material. Materials and methods: Forty single-rooted human teeth were prepared into dentin slices and drilled to form canal spaces. Samples were divided into four groups of 10 in each (n=10). In groups A and B, diode laser irradiations were performed, and then MTA was placed inside The canal spaces and incubated at 37°C for 7 days. After incubation, dentin slices in groups B and C were immersed in Biopure MTAD, and The last group served as control without any treatment. The push-out bond strengths were then measured by using a universal testing machine. Results: The means±standard deviations of push-out bond strength were 6.74±0.48, 5.95±0.40, 6.86±0.66, and 7.88±0.37 for groups A (laser), B (laser plus MTAD), C (MTAD) and D (control), respectively. One-way analysis of variance (ANOVA) test revealed significant differences among The groups (p<0.0001). Tukey's test did not show any significant difference between groups A and C (p=0.93). However, these differences were significant between groups A and B (p=0.006) and between groups B and C (p=0.001). Conclusions: The results of this study indicated that either diode laser or MTAD can lower The bond strength of MTA-dentin, and that diode laser irradiations plus MTAD might affect MTA bond to dentin negatively. © Copyright 2012, Mary Ann Liebert, Inc.


PubMed | Florida Institute for Advanced Dental Education, Shiraz University, University of Wisconsin - Madison and Kamal Asgar Research Center
Type: Comparative Study | Journal: American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics | Year: 2015

The aim of this study was to evaluate the effect of exposure to radiofrequency electromagnetic fields emitted by mobile phones on the level of nickel in saliva.Fifty healthy patients with fixed orthodontic appliances were asked not to use their cell phones for a week, and their saliva samples were taken at the end of the week (control group). The patients recorded their time of mobile phone usage during the next week and returned for a second saliva collection (experimental group). Samples at both times were taken between 8:00 and 10:00 pm, and the nickel levels were measured. Two-tailed paired-samples t test, linear regression, independent t test, and 1-way analysis of variance were used for data analysis.The 2-tailed paired-samples t test showed significant differences between the levels of nickel in the control and experimental groups (t [49]= 9.967; P<0.001). The linear regression test showed a significant relationship between mobile phone usage time and the nickel release (F [1, 48]= 60.263; P<0.001; R(2)= 0.577).Mobile phone usage has a time-dependent influence on the concentration of nickel in the saliva of patients with orthodontic appliances.


Saghiri M.A.,University of Wisconsin - Madison | Asatourian A.,Kamal Asgar Research Center | Haraji A.,University of Tehran | Ramezani G.H.,University of Tehran | And 3 more authors.
Biological Trace Element Research | Year: 2014

Previous studies on the endodontic broken stainless steel instruments have mainly focused on retrieval of specimens. However, the systemic consequences of the retained separated instruments need an investigation. The current study aimed to evaluate the correlation between broken stainless steel instruments inside the root canal space and the urinary level of iron (Fe) in patients. Sixty near-aged and same-gender patients were selected. Thirty patients in the control group had no endodontic treatment in their history, while the other 30 patients in the endodontic group had broken stainless steel instrument. The urine samples were collected in iron-free containers. All specimens were refrigerated for 1 day and then subjected to Fe level measurement by electrothermal atomic absorption spectrometry. Data were analyzed by Kolmogorov-Smirnov and t tests at P<0.05. The correlation coefficients of age and sex were also evaluated in relation with Fe levels in the urine. The level of Fe did not show any significant increase in the experimental group (P>0.05). There was a positive correlation between age and Fe levels of endodontic and control groups. However, the joint effects of age and sex on Fe levels were different for the two groups. The presence of broken stainless steel instruments inside the root canal space did not elevate the level of Fe in the urine of patients. However, this value was positively correlated with the patient age. © 2014 Springer Science+Business Media.


PubMed | University of Wisconsin - Madison, Kamal Asgar Research Center and Texas A&M University
Type: Journal Article | Journal: Journal of endodontics | Year: 2015

The aim of this study was to evaluate the impact of radiopaque additive, bismuth oxide, particle size on the physical properties, and radiopacity of tricalcium silicate-based cements.Six types of tricalcium silicate cement (CSC) including CSC without bismuth oxide, CSC + 10% (wt%) regular bismuth oxide (particle size 10 m), CSC + 20% regular bismuth oxide (simulating white mineral trioxide aggregate [WMTA]) as a control, CSC + 10% nano bismuth oxide (particle size 50-80 nm), CSC + 20% nano-size bismuth oxide, and nano WMTA (a nano modification of WMTA comprising nanoparticles in the range of 40-100 nm) were prepared. Twenty-four samples from each group were divided into 4 groups and subjected to push-out, surface microhardness, radiopacity, and compressive strength tests. Data were analyzed by 1-way analysis of variance with the post hoc Tukey test.The push-out and compressive strength of CSC without bismuth oxide and CSC with 10% and 20% nano bismuth oxide were significantly higher than CSC with 10% or 20% regular bismuth oxide (P < .05). The surface microhardness of CSC without bismuth oxide and CSC with 10% regular bismuth oxide had the lowest values (P < .05). The lowest radiopacity values were seen in CSC without bismuth oxide and CSC with 10% nano bismuth oxide (P < .05). Nano WMTA samples showed the highest values for all tested properties (P < .05) except for radiopacity.The addition of 20% nano bismuth oxide enhanced the physical properties of CSC without any significant changes in radiopacity. Regular particle-size bismuth oxide reduced the physical properties of CSC material for tested parameters.


Saghiri M.A.,University of Wisconsin - Madison | Saghiri M.A.,Kamal Asgar Research Center | Sheibani N.,University of Wisconsin - Madison | Garcia-Godoy F.,University of Tennessee Health Science Center | And 3 more authors.
Biological Trace Element Research | Year: 2013

This study aims to evaluate the correlation between the presences of separated endodontic instrument inside the dental canal and the nickel (Ni) level in the urine samples of subjected patients. Same-gendered and near-aged participants were selected and were instructed to collect their urine in sterile nickel-free plastic containers. The procedures were carried out in the office, and samples were stored in low-temperature cooler for 1 day and then they were transferred to the laboratory for electrothermal atomic absorption spectrometry. The level of Ni was measured and the correlation coefficient was calculated. Data were analyzed using t tests, Pearson's correlation coefficients, and linear regression analysis, at a level of significance P < 0.05. The statistical analysis has showed significant difference in Ni level between endodontic and control groups (P < 0.05). There was no correlation between Ni level in urine and the age or time period of broken instrument inside the canal; however, Ni level of urine and the age of participants in experimental group has demonstrated a positive correlation. The amount of Ni element can be increased in the urine of patients who have experienced broken endodontic instrument inside the dental canal. However, there is no positive correlation between the remaining pieces of instruments inside the canal and the elevation of nickel amount in urine during the tested time period. This issue suggested that the aging of remaining broken instrument inside the canal does not show any remarkable concern regarding the Ni elevation in the urine excreted by an individual. © 2013 Springer Science+Business Media New York.


Saghiri M.A.,University of Wisconsin - Madison | Asatourian A.,Kamal Asgar Research Center | Orangi J.,Kamal Asgar Research Center | Sorenson C.M.,University of Wisconsin - Madison | Sheibani N.,University of Wisconsin - Madison
Critical Reviews in Oncology/Hematology | Year: 2015

Trace elements play critical roles in angiogenesis events. The effects of nitrogen, iron, selenium, phosphorus, gold, and calcium were discussed in part I. In part II, we evaluated the effect of chromium, silicon, zinc, copper, and sulfur on different aspects of angiogenesis, with critical roles in healing and regeneration processes, and undeniable roles in tumor growth and cancer therapy. This review is the second of series that serves as an overview of the role of inorganic elements in regulation of angiogenesis and vascular function. The methods of exposure, structure, mechanism, and potential activity of these trace elements are briefly discussed. An electronic search was performed on the role of these trace elements in angiogenesis from January 2005 to April 2014. The recent aspects of the relationship between five different trace elements and their role in regulation of angiogenesis, and homeostasis of pro- and anti-angiogenic factors were assessed. Many studies have investigated the effects and importance of these elements in angiogenesis events. Both stimulatory and inhibitory effects on angiogenesis are observed for the evaluated elements. Chromium can promote angiogenesis in pathological manners. Silicon as silica nanoparticles is anti-angiogenic, while in calcium silicate extracts and bioactive silicate glasses promote angiogenesis. Zinc is an anti-angiogenic agent acting on important genes and growth factors. Copper and sulfur compositions have pro-angiogenic functions by activating pro-angiogenic growth factors and promoting endothelial cells migration, growth, and tube formation. Thus, utilization of these elements may provide a unique opportunity to modulate angiogenesis under various setting. © 2015 Elsevier Ireland Ltd.


Saghiri M.A.,University of Wisconsin - Madison | Asatourian A.,Kamal Asgar Research Center | Orangi J.,Kamal Asgar Research Center | Sorenson C.M.,University of Wisconsin - Madison | Sheibani N.,University of Wisconsin - Madison
Critical Reviews in Oncology/Hematology | Year: 2015

Many inorganic elements are recognized as being essential for the growth of all living organisms. Transfer of nutrients and waste material from cells and tissues in the biological systems are accomplished through a functional vasculature network. Maintenance of the vascular system is vital to the wellbeing of organisms, and its alterations contribute to pathogenesis of many diseases. This article is the first part of a review on the functional role of inorganic elements including nitrogen, iron, selenium, phosphorus, gold, and calcium in angiogenesis. The methods of exposure, structure, mechanisms, and potential activity of these elements are briefly summarized. An electronic search was performed on the role of these elements in angiogenesis from January 2005 to April 2014. The recent aspects of the relationship between different elements and their role in angiogenesis, and production of pro- and anti-angiogenic factors were assessed. Several studies emphasized the role of these elements on the different phases of angiogenesis process in vivo. These elements can either enhance or inhibit angiogenesis events. Nitrogen in combination with bisphosphonates has antiangiogenic effects, while nitric oxide promotes the production of angiogenic growth factors. Iron deficiency can stimulate angiogenesis, but its excess suppresses angiogenesis events. Gold nanoparticles and selenium agents have therapeutic effects due to their anti-angiogenic characteristics, while phosphorus and calcium ions are regarded as pro-angiogenic elements. Understanding how these elements impact angiogenesis may provide new strategies for treatment of many diseases with neovascular component. © 2015 Elsevier Ireland Ltd.


PubMed | University of Wisconsin - Madison and Kamal Asgar Research Center
Type: Journal Article | Journal: Journal of endodontics | Year: 2015

Dental pulp regeneration is a part of regenerative endodontics, which includes isolation, propagation, and re-transplantation of stem cells inside the prepared root canal space. The formation of new blood vessels through angiogenesis is mandatory to increase the survival rate of re-transplanted tissues. Angiogenesis is defined as the formation of new blood vessels from preexisting capillaries, which has great importance in pulp regeneration and homeostasis. Here the contribution of human dental pulp stem cells and proangiogenic and antiangiogenic factors to angiogenesis process and regeneration of dental pulp is reviewed.A search was performed on the role of angiogenesis in dental pulp regeneration from January 2005 through April 2014. The recent aspects of the relationship between angiogenesis, human dental pulp stem cells, and proangiogenic and antiangiogenic factors in regeneration of dental pulp were assessed.Many studies have indicated an intimate relationship between angiogenesis and dental pulp regeneration. The contribution of stem cells and mechanical and chemical factors to dental pulp regeneration has been previously discussed.Angiogenesis is an indispensable process during dental pulp regeneration. The survival of inflamed vital pulp and engineered transplanted pulp tissue are closely linked to the process of angiogenesis at sites of application. However, the detailed regulatory mechanisms involved in initiation and progression of angiogenesis in pulp tissue require investigation.

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