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Showing 10 results for Razmi

H. Razmi , A. Rigi Ladez,
Volume 11, Issue 2 (8 1998)

  In Present research study, 44 canine teeth of with completely formed apex was selected in 11 cats. Jaw bones were removed while teeth were kept intra alveolar sockets and routine root canal therapy was performed on each root. Afterwards, 3mm of each root were cut apically. 20 teeth underwent cavity preparation via high speed dental turbine and round diamond bur, 20 via endosonic device and 4 (10% of all) remained untreated as control group. Then, the cavity walls were assessed with stereomicroscope while the teeth were still kept in their alveolar sockets in order to detect cracks.

H. Razmi , M. Salavati Zadeh ,
Volume 14, Issue 2 (9 2001)

The idea of using chemical agents in removal of obstructions on the walls of root canals has been existing since years ago. Successful attempts in this area have been made with the introduction of RC-Prep materials in root canal preparations. The aim of this study was to compare the decalcifing potency of two chelating agents in root canal preparations. 30 extracted canines were divided in three groups for use of Re- Prep materials. Group A Rc-Prep (Primer) made in USA, group B Re- Prep (RC-CTF) made in Iran, and group C as control. Root canals were prepared using standard method followed by washing with 5% sodium hypochloride. Then the teeth were divided into two sections of mesial and distal by a special cutting device. The amount of calcium on polished sections was measured using an elemental analysis method (electron beam probe system). The mean value data were analysed using one‌way Analysis of Variance (ANOVA). The mean values for the measured calcium were group A: 28713±1129, group B: 39441+680, and group C: 54458±2024 . Statistical analysis showed that the mean value for group A was significantly different from other groups. There was also significant difference in the mean values for group B and C. The results indicate that the decalcifing potency for Rc-Prep (Primer, USA) is significantly higher (PO.001) than that of Rc-Prep (RC-CTF).
H. Razmi , D. Sharifi , F. Sasani , M. Eghdami ,
Volume 14, Issue 3 (9 2001)

The cleaning and shaping of root canals is one of the most important proccesses in endodontics. In many cases, the physiologic or pathologic proccedures can affect the canals. So, using the instruments and materials, which could be applied in cleaning and shaping of narrow canals is necessary. The aim of this study was the evaluation of Iranian and foreign chelating agents on periradicular tissue of cats. After cleaning and shaping of canals in 18 lower canines of cats, the original RC-Prep and an Iranian chelating agents were placed equally in two groups with 9 teeth in each one. The patency of canals preserved for materials leakage. In 3 lower canines of cats, phosphoric acid was placed as positive controls.3 canine teeth as negative controls had nothing in them. The crowns were sealed and the cats were sacrificed in 1/21/42 days periods after conducting vital perfussions. The teeth samples with their surrounding osseous tissues were gathered and placed in three groups each contained 6 samples. Histologic preparations were done and the tissue reactions to these materials were evaluated by counting the proliferative inflammatory cells. Also the morphometric analysis for these samples was done. The inflammatory reactions of these materials (the original RC-Prep. & the Iranian chelating agent) were not statistically different. Both of these materials were different in inducing tissue reactions in comparison with those of positive and negative controls, and these differences were statistically important.

H. Razmi , A . Yousefi ,
Volume 16, Issue 3 (10 2003)

Statement of Problem: The goal of a successful endodontic surgery is to establish an adequate seal in apical region. Therefore during surgery, root-end resection is essential for an appropriate situation and proper access.
Purpose: The aim of this study was to determine the most appropriate root-end resection angle to establish adequate apical seal in periapical surgery
Materials and Methods: Forty-five intact extracted human maxillary central incisors were randomly divided into three 15-tooth groups. The root canals were instrumented and then obturated using lateral condensation technique. AM roots were resected at 3mm from apical portion. Angles of root resection for each group were 0, 30 and 45 degrees. Then all teeth surfaces, except the cut ones, were covered with nail polish and immersed in methylen blue for 7 days. After 7 days, nail polish was removed from the surfaces and samples were split in buccolingual direction. Then, dye penetration (mm) was measured using a stereozoom microscope (Loupe) [X4 magnification] and eye lens. In order to analyze the data, unilateral variance analysis was used.
Results: The values of dye penetration were: 7.23±3.34 (0°), 8.46±3.01(30°) and 9.74±4.11 (45°). There
was no significant difference between three groups (P>0.05).

Conclusion: It is suggested that the angle of root-end resection put a limited effect on apical seal if retrograde cavity depth is increased.

H. Razmi , M. Aligholi , Sd. Sadeghi ,
Volume 19, Issue 4 (6 2007)

Background and Aim: Many studies have shown that microorganisms are the main cause of pulpal diseases and the main purpose of root canal therapy is their elimination from the root canal system. Antiseptic agents are used to reduce bacteria but their antibacterial activities differ from in vivo to in vitro studies and might be inactivated by dentin and its components in root canal space. This study was designed to investigate the effect of dentin on antibacterial activity of different antimicrobial agents.

Materials and Methods: In this experimental study, two antibacterial agents (sodium hypochlorite and chlorhexidine) with different concentrations were used in four experimental groups: Group 1: dentin, Group 2: demineralized dentin with EDTA, Group 3: dentin matrix and Group 4: dentin mineral component. The species used in this study was Entrococcus faecalis. Different concentration of agents were added to mixture of each experimental group and bacteria. At the baseline and after one and 24 hours, samples were collected and cultured. After incubation period, colonies were counted. Data were analyzed by Tukey test with p<0.05 as the limit of significance.

Results: 2% and 0.2% chlorhexidine, and 5% sodium hypochlorite solutions at the three studied times eliminated Entrococcus faecalis completely. 1% sodium hypochlorite eliminated all bacteria in 1h and 24 hs. Statistical analysis showed significant differences between experimental and control groups (P<0.05). Sodium 1% hypochlorite at time 0, could reduce bacteria significantly (P<0.05) but didn’t eliminate them completely.

Conclusion: Inactivation of intracanal antiseptics was not observed in this study. As elimination of bacteria occurred, application of these antibacterial agents are recommended in endodontic treatment. Further investigations on other antibacterial agents, other concentrations and shorter time intervals are recommended.

Mr. Sharifian , M. Zarrabian , H. Razmi , M. Ghobadi , Mj. Kharrazifard , F. Hemmatzadeh , R Afzalifar ,
Volume 20, Issue 2 (9 2007)

Background and Aim: Mineral Trioxide Aggregate (MTA) is a material used in many endodontic problems. Recently a number of studies, have reported that Portland Cement (PC) and MTA have similar physical, chemical and biologic properties. In addition, a material known as Root MTA which is produced in Iran has been claimed to have similar properties to Pro Root MTA. If these claims are true, possible use of PC and Root MTA in clinic instead of Pro Root MTA will be quite cost effective. The aim of this study was to investigate the toxicity of Pro Root MTA, Root MTA and Portland Cement on L929 mouse fibroblasts.

Materials and Methods: In this experimental study 0, 4, 24 hours and 7 days' extracts of materials were transferred to cell culture plates containing L929 fibroblasts. After 24 hours incubation, cells were stained by Neutral Red (NR), and optical density (OD) of each cell was read with ELISA reader. Data were analyzed using Tukey HSD and one way analysis of variance. P<0.05 was considered as the level of significance.

Results: In all surveyed groups and negative control group, at all time points separated cells from the base of the well were round. Refraction which is a characteristic of cellular death was not observed, whereas the separated cells from the base of well in positive control group showed refractional characteristic.

Conclusion: Based on the findings of this study Pro Root MTA, PC and Root MTA have the same biocompatibility. PC seems to have the potential to be used in the same clinical situation as MTA. However in order to replace MTA with these less expensive materials more in vitro and in vivo studies are suggested.

H. Razmi , Sn. Ostad , S. Fayyazi ,
Volume 21, Issue 1 (14 2008)

Background and Aim: Several materials have been introduced for retrograde fillings, pulp capping and sealing root perforations, but their biological effect on vital tissues and cells is not clear. The purpose of this study was to evaluate the reaction of human periodontal ligament fibroblasts to four root canal filling materials: Pro Root MTA, Root MTA, Portland cement and amalgam.

Materials and Methods: In this experimental study, impacted or semi impacted third molar teeth were extracted in aseptic conditions and tissues around the roots were used to obtain fibroblast cell line. After proliferation, cells were cultured in chamber slides and extracts of materials were added to wells. Fibronectin, type I collagen and TGF-  expression were measured by immunocytochemistry method. Data were analyzed by SPSS 11.0 using one way ANOVA and Tukey test. P<0.05 was considered as the limit of significance.

Results: Collagen I expression was higher in Pro Root MTA group after 24 hours (p<0.05) and in Portland cement group and positive controls after 48  hours. Portland cement group showed the highest expression of collagen after 1 week. There was no significant difference in fibronectin expression after 24 hours. After 1 week the highest expression of fibronectin was seen in Portland cement, Root MTA and Pro Root MTA groups. TGF-  expression was higher in amalgam, Root MTA and Pro Root MTA specimens after 24 hours and was the highest in Pro Root MTA group after 48 hours.

Conclusion: Based on the results of this study, Portland cement and Root MTA are comparable with Pro Root MTA and better than amalgam regarding their effects on human periodontal ligament fibroblasts.

H. Razmi, N. Shokouhinejad, R. Fekrazad , P. Motahhary, M Alidoust,
Volume 22, Issue 4 (21 2010)

Background and Aims: Considering advantages and disadvantages of mineral trioxide aggregate (MTA), Calcium Enriched Mixture (CEM) cement has been developed recently. The purpose of this study was to compare the apical microleakage of the root-end cavities prepared by ultrasonic or Er,Cr:YSGG laser and filled with MTA or CEM cement.

Materials and Methods: Eighty single-rooted, extracted human teeth were instrumented and obturated. Root-end resection was made by removing 3 mm of the apex. The teeth were randomly divided into two experimental (n=30) and two positive and negative control (n=10) groups. After that, the retrograde cavities were prepared using ultrasonic or Er,Cr: YSGG Laser. According to the root-end filling materials (MTA or CEM cement), each group was then divided into two subgroups. Finally, specimens were cleared for assessing the amount of apical dye (Indian ink) penetration. The data were analyzed using Kruskall-Wallis and Dunn tests.

Results: Laser/CEM cement group showed significantly the lowest mean apical dye penetration. There were no statistically significant differences between Laser/MTA, ultrasonic/MTA and ultrasonic/CEM cement groups.

Conclusion: Based on the findings of this study, CEM cement demonstrated lower rate of apical leakage compared with MTA, when the root-end cavities prepared with Er,Cr:YSGG Laser. The sealing ability of MTA was not different following root-end preparation by ultrasonic or Er,Cr:YSGG Laser.

Amin Sobhani Mohhsen, Hasan Razmi, Mona Sadegh,
Volume 26, Issue 3 (8-2013)

  Background and Aims: Successful root canal therapy requires knowledge of tooth anatomy and root canal morphology. For permanent mandibular premolars, great variety in size, shape and number of roots and root fusion expression has been reported in the literature. There is a wide variety of methods used in studies for evaluating the root canal morphology. One of these methods is Cone-beam Computed tomography (CBCT) that reduces the limitations of two-dimensional X-ray imaging, with less exposure in comparison with other 3D radiographies. Thus, this study was designed to evaluate the differences in the root and canal morphology of permanent mandibular premolars in an Iranian population by means of CBCT images.

  Materials and Methods: We searched a database of CBCT scans and evaluated 400 (20-60 years old) patients who met the inclusion criteria and teeth in this images (CBCT) were evaluated in three dimensions (Axial, Coronal and Sagital). Tooth length, number of roots, number of canals, canal type, root curvature and the effect of gender on any of the items mentioned were evaluated. Data were analyzed using T-test.

  Results: The average length of the first premolar of mandibular was 22.27 mm and second premolar was 22.28 mm. 98.4% of the first premolar and 98.2% of the second premolar were single root., and 87.3% and 93.1% were single channel. The incidence of number of canals based on vertochy divisions were:type 1: 90.7% and 90.8%, type 0: 2.2% and 2.8%, type 4: 3.3% and 3.1%, type 6: 1.4% and 2.1% and type 3: 2.5% and 1.5% respectively. In any case, there was no significant difference between males and females (P<0.001).

  Conclusion: Results indicate that dentists can obtain valuable information about the anatomy and morphology of the root canals using CBCT.

Noushin Shokouhinejad, Hassan Razmi, Mehrfam Khoshkhounejad, Pegah Firouzmanesh,
Volume 30, Issue 3 (10-2017)

Background and Aims: The aim of this study was to assess the microhardness of BioMTA (OrthoMTA, RetroMTA) in distances of 0.5, 2 and 3.5 mm from the exposed surface to blood, phosphate buffer saline (PBS) or distilled water and to compare to that of ProRoot MTA.
Materials and Methods: One hundred and thirty five semicylindrical polymethyl methacrylate were filled with either ProRoot MTA, OrthoMTA, or RetroMTA. Fifteen molds in each group were exposed to blood, 15 molds to PBS and the other 15 to distilled water. The microhardness of the materials at 0.5, 2 and 3.5 mm distance from the exposed surface to phosphate-buffered saline (PBS) as a synthetic tissue fluid, blood, and distilled water was assessed. The data were analyzed using one-way ANOVA and Tukey post hoc tests.
Results: Exposure to blood significantly decreased the microhardness of all materials at all three points of 0.5, 2 and 3.5 mm (P<0.001). At level of 0.5 and 2 mm distant from blood, OrthoMTA showed significantly the least microhardness value; however, at the point of 3.5 mm, the microhardness of RetroMTA was higher than the two other materials (P<0.001). After exposure of samples to distilled water or PBS, no significant difference was found between the materials at any levels of 0.5, 2, and 3.5 mm (P<0.01).
Conclusion: Blood exposure resulted in the decrease of microhardness of internal part of the materials.

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