Aim: The aim of this study was to compare the effects of Ethylen glycol tetra acetic acid (EGTA) and EDTA for their smear layer removal capability using scanning electron microscopy technique.Material and Methods: A group of 28 single rooted teeth were instrumented to size 60 master file. Four teeth were also kept as control while the remaining teeth were divided into two groups. Group A: in which 12teeth were irrigated with 10 ml of 17% EGTA for 2 minutes? Group B: consisted of 12teeth irrigated with 10 ml of 17% EDTA for 2 minutes. Both groups were then irrigated with 10 ml of 5% Naocl. the control group were just irrigated with 10 ml of 5 % Naocl. All teeth in then the control group were only irrigated with 10 ml of 5% Nacl. Specimeus were then sectioned longitudinally. A scanning electrone microscope was wsed to in vetig ate the intenal surfaces of the canal.Results: EGTA chelated dentin surface more conservatively than EDTA without causing erosion.Conclusion: It seems that EGTA can be used safely to remove smear layer from the canal surfaces.

The aim of the present study was the histological evaluation of Enamel Matrix Derivative (EMD) effectiveness for regeneration of periodontal defects. EMD activates cementum synthesis, PDL and bone during the maturation stage of follicole. In this research, EMD was used in surgical defects of premolar teeth in four adult sheep. Muccoperiosteal flap was reflected in buccal site of teeth. The buccal bone plate was removed from mesial to distal in 4 mm depth. After eliminating the cementum by bur and its etching, EMD was applied on exposed dentine and flap was sutured. In opposite sites of those teeth (control sites) the same process was performed without etching. After 100 days, sheep were sacrificed and histological study through light microscopic was performed on black sections of operation sites. The results showed that in test sites, regeneration of cementum and bone was 62/5% and 42/5-50% respectively. But in control sites regeneration of cementum and bone was 37.5% and 32/5-42/5% respectively. Also the migration of junctional epithelium in control sites was 8-10% more than test sites. The important point is that in test sites, cementum was completely attached to undermining dentine. But, in control sites, the gap between cementum and dentine was visible. As a result, this study suggests that EMD promotes periodontal regeneration, and EMD application is a successful achievement in regenerative periodontal therapy.

Double-layer sheet forming methods are developed in various industries due to their dual properties and wide application. In this paper, the numerical and experimental investigation of the bowing defect in the flexible roll forming process of double-layer sheets have been discussed. Numerical analysis has been conducted using Abaqus finite element software and experimental tests using a single-station flexible roll forming machine. After validation of the numerical model, the effects of significant parameters on the bowing defect in the flexible roll forming process, including the forming angle, sheet thickness, sheet wing length, and the displacement of sheet layers have been investigated using full factorial design of experiments method and finite element simulations. The results were analyzed using the Analysis of Variance statistical method. The results showed that with increase of the forming angle and wing length, the amount of bowing defect increases while it decreases with the increase of the thickness of the sheet. Also, the arrangement of layers is also effective in the occurrence of the bowing defect. The results showed that the bowing defect in the Al-Cu layer material increased from 2.152 to 2.646 mm with the increase of the wing length from 18 to 25 mm.

Statement of Problem: The goal of bone regenerative therapy is to reconstruct the damaged tissues to initial condition, which seems so important in periodontology and implantology. In such therapies, different biomaterials, with some advantages and disadvantages, may by use.Purpose: The aim of this research was to evaluate the quality, bone trabecular density and thickness of newly forming bone as well as foreign body reaction against Biostite®, in comparison with the control group.Material and Methods: In this experimental study the total number of 5 sheep was operated with general anesthesia. At first 10 standard defects were created in 5x5x5 mm on the left and right edentulous mandibular ridge. Five defects were randomly treated by Biostite®, the remaining five were considered as controls. After six months, the sheep were sacrificed and the separated defect areas with intact margin were placed in 10% formalin and prepared for histologic and histomorphometric study. To analyze the data, Mann- Whitney U test was used.Results: The mean percentage of new bone formation in Biostite®group was statistically more han the control group (P<0.05). Newly formed bone was vital in both groups which was a combination of lamellar and woven types, however, the thickness and density of new bone in biostite® group was more than the controls. Foreign body reaction was observed in Biostite® group. Conclusion: It is suggested that Biostite® synthetic material can be useful in bone regenerative therapies.

In this paper, an atomistic based finite element model is developed to investigate the influence of topological defects on mechanical properties of graphene. In general, plane stiffness matrix of the hexagonal network structure of graphene is found. The effective elastic modulus of a carbon ring is determined from the equivalence of molecular potential energy related to stretch and angular deformation. A hexagonal carbon ring as a unit cell of the graphene sheet is modeled by four-node elements. Applying three-node triangular elements, Stone-Wales (SW) defect which is an important topological defect is also modeled. In this method, both pristine structure of graphene and graphene with SW defect are considered and to get more real structure, an atomistic model of a small part of graphite sheet around the defect site, is modeled in Gaussian software and new arrangement around SW defect are obtained by minimizing its energy. Young’ s modulus, shear modulus and Poisson’ s ratio of the pristine single-layered graphene sheet (SLGS) and the effect of topological defects on the elastic properties of SLGS were examined. The numerical results from this new model showed good agreement with data available in literature.

Environment and its conservation is one of the present issues in risky modern life. Although, the present world has been improving during last years, it hasn’t been able to solve environmental problems and it has caused its deterioration. Littering in jungle, seashore, public places and passages is one of the significant environmental issues in society of Iran. The Purpose of the present study is investigation of the reasons of littering formation by the approach of Causal Layered Analyses (CLA) and planning scenario. The present study analyzed the layers forming the present social issue and searched the origin of it. In order to accomplish this study, 15 experts in environment and society were interviewed by Qualitative and exploring method and applying deep interview technique. Then, after exploiting the contents and content analysis of interviews, their opinions presented in 4 forms as litany, systematic, discourse analysis and metaphor. By applying the present discourses, the gap between state-people and people-people were recognized as important variables and were applied in presenting scenario. Finally 4 scenarios presented in a diagram which can help strategists and officials of the society.

Medicinal plants contain active ingredients in one or some of their organs. Squalene is one of the active ingredients that prevent heart attacks and cardiovascular diseases and protect the body from some cancers. The aim of the present study was to investigate the presence of squalene in a number of medicinal plants. In this experiment, the plant oils were extracted and measured using Bligh & Dyer with minor changes. TLC (thin layer chromatography) was used to identify squalene. Comparison of TLC of standard squalene with TLC of the investigated medicinal plant samples showed that Caryophillium aromaticus, Descurainia sophia, Portulaca Oleracea, Papaver somniferum and Nigella Sativa contained squalene. Although the percentage of Papaver somniferum and Nigella Sativa seed oil was higher than other medicinal plants, the squalane spot of clove plant had a higher intensity of color and this indicates a higher concentration of squalene in this plant.