فهرست مطالب milad soleimani

Surface-modifying biomaterials have the potential to improve both the performance and durability of dental implantable products that are currently in use. Dental implants' surfaces may be modified to improve their biocompatibility and other biologically significant characteristics using metal and metal oxide nanoparticle coatings. The toxicity of the materials used in the synthesis, the requirement for high temperature and energy, and the high cost are just a few of the factors that restrict the use of the various physical and chemical methods for the synthesis of metal nanoparticles. Though, these restrictions can be overcome by developing substitute synthetic approaches that are similar to Green Synthesis and have proven to be more eco-friendly and less toxic, including the use of algae, microorganisms, and plants. Metal ions can be readily reduced into nanoparticles by plants' biomolecules, secondary metabolites, and coenzymes. Although still in its infancy, the use of metal nanoparticles produced through green synthesis in dental implants has the potential to open up new avenues for enhancing the caliber of these goods.

Green Synthesis is a method for synthesizing nanoparticles using protein, carbohydrates, plant extracts, and similar structures, which has made it a simple, cost-effective, environmentally friendly, and repeatable method compared to chemical methods. This study was conducted to investigate the antibacterial effect of silver nanoparticles (Ag-NP), synthesized by the extract fruit of Prosopis fracta, on Streptococcus mutans bacteria as the cause of tooth decay. The synthesized nanoparticles were identified through the UV-Vis spectrophotometer, transmission electron microscope (TEM), and powder X-ray diffraction (PXRD) methods, while their antibacterial effect was evaluated by the usage of microbroth dilution test. UV-Vis spectroscopic analysis displayed the presence of a peak in the range of 425-445 nm and indicated the successful synthesis of nanoparticles in the extract. Meanwhile, the average size of our product was determined by the TEM image to be about 30 nm. According to the investigation results, the synthesized nanoparticles exhibited satisfying antibacterial effects against the studied bacteria.

 Facial asymmetry in orthodontic treatments can be evaluated by both posteroanterior (PA) cephalograms and cone-beam computed tomography (CBCT) images. This study aimed to assess the agreement between CBCT and two-dimensional PA images in terms of cephalometric measurements.

 In this descriptive analytical study, CBCT and PA radiographs were taken from nine human dry skulls. Two observers marked the bilateral landmarks including CO (orbit center), J (jugale), 6C, 6A, 1A, 1C, GO (gonial angle), AG (antegonion), AR (articular) and Ma (mastoidal). The distance between two identical points on both sides was measured on both the PA and CBCT images. The differences were calculated and the agreement between the two modalities was checked by using intraclass correlation coefficient (ICC).

 The mean differences between CBCT and PA measurements were as following: for CO=1.48, J=11.64, U6C=0.75, U6A=1.8, L6C=13.33, L6A=3.0, U1C=0.96, U1A=0.62, L1C=0.22, L1A=0.45, GO=0.87, AG=6.67 and AR=0.71 mm. The agreement was the highest for GO (ICC=0.931) and CO (ICC=0.902), and the lowest for U6A (ICC=-0.041) and J (ICC=0.038) landmarks.

 Given the negligible differences between the two modalities, conventional PA cephalograms can be as competent as CBCT in detecting maxillofacial asymmetry with lower patient radiation dose.

 Repeatability and accuracy of measurements made on cone-beam computed tomography (CBCT) images are critical in dental practice especially in implantology. The aim of this study was to investigate the reproducibility of linear measurements made on reconstructed CBCT images.

Methods:

 In this in vitro, experimental study, 5 radiopaque markers were attached to the molars (left and right side), premolars (left and right side) and midline areas of 10 human cadaver dry mandibles. The distance between the markers and the lower border of the mandible was measured by a digital caliper and considered as the gold standard. CBCT images were taken, and the distance between the markers and the lower mandibular border was measured on cross-sectional images by three maxillofacial radiologists using Romexis software. The same measurements were made 1 month later to assess the reproducibility of measurements. The intra-class correlation coefficient was calculated to assess the repeatability and agreement between the observers.

 Compared with the gold standard, the mean error percentage in linear measurements was calculated to be 3.25%. The overall reproducibility of CBCT linear measurements was 0.865. The inter-observer agreement was calculated to be 0.972.

CBCT showed acceptable accuracy, repeatability and reliability for linear measurements, and can be used as an accurate tool for this purpose.

 Thalassemic patients commonly present malocclusions, which require both orthognathic treatments and surgury. This study aimed to assess prioritizing the surgery over orthodontic treatment.

Case report: 

Surgery-first method was performed to treat severe gummy smile and mild retrognathic mandible and prognathic maxilla in a 24-year-old Iranian girl with major β-thalassemia. Brackets and Ni-Ti wires were adjusted on all teeth to align their levels for one month. Then, the patient underwent the surgery, and the soft tissue was excised for Lefort dissection by two cutting lines, followed by osteotomy. Afterwards, down fracture and bilateral septoplasty were carried out, and excessive bones were removed.  The surgery retruded the maxilla by 10 mm.

 The 2-year follow-up revealed no overgrowth of the maxilla or malocclusion.

 Surgery-first method can be successfully used for treatment of malocclusions in patients with major thalassemia.

Maintaining periodontal health in patients undergoing orthodontic treatment is crucial. Biotype is a substantial factor to be considered in this regard. The aim of this systematic review was to investigate the scientific evidence with respect to the relationship between biotype and marginal periodontal alterations induced by orthodontic interventions.

The electronic search was conducted for pertinent studies at three databases: PubMed, Scopus, and Cochrane up to August 1, 2019 based on a detailed protocol according to the PRISMA statement. The authors also completed a hand search in six dental journals and the bibliographic list of the relevant studies.

Of 1512 citations retrieved through the electronic search, 602 were duplicate entries. Evaluating titles, abstracts, and full texts, 8 articles succeeded the inclusion criteria; however, no relevant studies was found through hand searching. The evidence suggested that recession was negatively associated with the thickness of the facial margin. These findings are more evident in proclination and using fixed appliances.

The existing evidence suggests that orthodontic therapy may result in small detrimental effects to the periodontium, especially in patients with thin biotype. However, due to the limited investigations and their inconsistent methodology, further well-designed prospective studies are needed.

Oil base fluids pose many hazards to the environment. The core of these fluids is gas oils, which are mixed with other chemicals to provide the proper rheology of a drilling fluid. During the drilling of an oil well, drilling waste may contaminate both the well and the surface, so that large volumes of hazardous chemicals enter the aquifers from the surface. In this study, we investigate the feasibility of using hydrogels for the purpose of making an environmentally friendly aqueous base fluid and replacing it with an oil base fluid in one of the oil fields located in the south of the country, The drilling fluid must have all the requirements for remove cuttings, creating the proper hydrostatic pressure for the well, maintain well bore stability, preventing shale activation. First, the rheological parameters of the mud fluid were measured without the presence of hydrogels, and then we used different amounts of this hydrogel in the mud production and again, we measured the drilling mud parameters.

Correlation of oils to each other and to their source rock is an important factor in defining a basin’s petroleum system. In this paper, 4 oil samples (#A13, #A09, #A04, #A03) from Sarvak reservoir and 2 source rocks (#SO1, #SO2) from Ahmadi member of Sarvak Formation in an oil field at southwest of Iran, were evaluated geochemically with Rock-Eval pyrolysis, column chromatography, gas chromatography (GC) and gas chromatography mass spectrometry (GC-MS) instruments. Moreover, thin section studies and Rock-Eval analysis along with biomarker data on source rock of Ahmadi member from Sarvak Formation indicate deep marine condition and kerogen type II. Determination of saturate, aromatic, resin and asphaltene fractions on study samples show paraffinic composition with nearly high thermal maturity for oils and naphtenic composition for extracted bitumen of probable source rock in studied oil fields. Geochemical studies indicate that the source rock of oil samples have carbonate-shale lithology in an anoxic marine environment. The biomarker ratios also show the medium to high thermal maturity of studied samples. Finally, star diagram of normal alkane and biomarker ratios, triangle diagram of C27-C28-C29 steran, variation of CPI, Pr/(Pr+Ph), C32 S/(S+R), C30 (βα/αβ+βα), C23 TT/C30 αβ Hopane and Tm/Ts versus calculated vitrinite reflex indicate that there are nearly biomarker similarities between #A03, #A04 and #A13 and source rock and can show genetic relationship. While #A09 oil sample with more space related to other samples might indicate more than one oil families in Sarvak reservoir of studied oil fields.

The importance of improving energy efficiency in the industry and its sub-sections is that reduce the cost of production at the macro level, Pay less subsidies and reduce the cost of industrial products. In this way, enhanced the value added of these sectors and increase competitiveness, enhance product quality, and ultimately, reduce imports some of important goods and increase exports of some products that made. This study examines the effect of eliminating energy subsidies on the energy intensity in iran industry using the approach of seasonal time series data in during 1385-1392 with Cobb-Douglas cost function that negative correlation between energy intensity and energy prices approved. Also results show that over time with advances in technology, energy intensity is decreased. Then energy price liberalization scenario, assuming a steady rise in nominal prices for the period 1393-1389 is studied. The results show that after the liberation of energy prices, energy intensity is decreased so that the highest reduction in the first year of liberalization and in the years following the reduction of energy intensity has decreased.