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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. Source


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. Source


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. Source


Davarmanesh M.,Shiraz University of Medical Sciences | Miri R.,Shiraz University of Medical Sciences | Haghnegahdar S.,Shiraz University of Medical Sciences | Tadbir A.A.,Shiraz University of Medical Sciences | And 5 more authors.
Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology | Year: 2013

Objective This study evaluated the effect of standardized bilberry extract containing anthocyanosides on chemotherapy-induced oral mucositis in hamsters. Study Design Twenty-four hamsters were randomly chosen and assigned to groups. Groups A and B were pretreated with deionized water, whereas group C was pretreated with bilberry extract daily for 7 days. Groups B and C underwent chemotherapy by intraperitoneal injections of 5-fluorouracil (days 4, 9, and 14); group A received normal saline. Potentiation of oral mucositis was achieved by scratching both cheek pouches of all animals with needles (days 5, 6, and 14). The pouches were histopathologically examined on day 17 after visual examination and blood sampling by cardiac puncture. Results The bilberry extract group showed significantly lower oral mucositis clinical and histopathologic scores (P <.05) and less percentile of mean daily weight reductions compared with animals receiving vehicle. Conclusions Frequent administration of bilberry extract had a protective effect on oral mucosal damage induced by 5-fluorouracil in an animal model. © 2013 Elsevier Inc. All rights reserved. Source


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. Source

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