Natural frequency under initial stresses for simply supported cross-ply composite laminated plates (E glass- fiber) are obtained using Refind theory (RPT). This theory accounts for parabolic distribution of the transverse shear strain through the plate thickness and satisfies the zero traction boundary conditions on the surfaces of the plate without using shear correction factors. The governing equations for Eigen value problem under initial stress are derived using Hamilton’s principle and solved using Navier solution for simply supported cross-ply symmetric and antisymmetric laminated plates. The effect of many design factors such as modulus ratio, thickness ratio and number of laminates on the Natural frequency and buckling stresses

The mobile phone has become one of the most important in our days. The effects of waves from mobile base station may cause health effects on human. The aim of this work was to study the effect of radiofrequency (RF) emitted from mobile base station on the hemoglobin (Hb), packed cell (PCV), white blood cells (WBC) and liver enzymes activity including glutamic oxaloacetic transaminase (GOT), glutamic pyruvie transaminase (GPT) and Alkaline phosphatase (ALP). In this study the people divided into control group who living away from mobile base station and experimental group who living near to the mobile base station. The present result found there is no significant differences (P<0.05) in the Hb and PCV, but there was a significant increases (

Background: Many studies have been conducted to evaluate the effect of using a hot material in the root canal and its potential for causing damage to the tooth supporting structure. Materials and methods: thirty permanent premolars were obturated with thermoplasticized Gutta-Percha using three different obturation techniques: soft core, Thermafil, and obtura to evaluate the rise in temperature on the root surface using a multipurpose digital thermometer. Results: temperature increases was significantly greater for Obtura versus Soft core (p<0.003), not significant for Thermafil versus Soft core (p<0.087), and Thermafil versus Obtura (p<0.125). Conclusions: temperatures rise on the root surface were below the critical level and, therefore, s

Background: Molars and premolars are considered as the most vulnerable teeth of caries attack, which is related to the morphology of their occlusal surfaces along with the difficulty of plaque removal. different methods were used for early caries detection that provide sensitive, accurate preoperative diagnosis of caries depths to establish adequate preventive measures and avoid premature tooth treatment by restoration. The aim of the present study was to evaluate the clinical sensitivity and specificity rates of DIAGNOdent and visual inspection as opposed to the ICDAS for the detection of initial occlusal caries in noncavitated first permanent molars. Materials and Methods: This study examined 139 occlusal surface of the first permanent

Background: Laser is a novel physical therapy technique used to treat various conditions, including wound healing, inhibition of bacterial growth, and postoperative wounds. High-power pulsed alexandrite laser therapy is one of the most prevalent forms of laser therapy, which is a noninvasive method for treating various pathological conditions, thereby enhancing functional capacities and quality of life. It is a modern medical and physiotherapeutic technology. Generally, the Alexandrite laser emits infrared light with a wavelength of 755 nm, allowing it to propagate and penetrate tissues. Objective: This study focused on the application of a high-power pulsed alexandrite laser in vitro to evaluate the effect of a pulsed alexandrite l

Background: The marginal seal is essential for sealant success because penetration of bacteria under the sealant might allow caries onset or progression. The aim of the present study was to estimate and compare the microleakage of pit and fissure sealant after various methods of occlusal surface preparation. Materials and methods: Thirty non-carious premolars extracted for orthodontic reasons were equally divided into three groups. In group one, occlusal fissures were opened with round carbide bur, in group two, occlusal surfaces of the teeth were cleaned with a dry pointed bristle brush and samples of group three were cleaned with a slurry of fine flour of pumice in water using rubber cup. Then fissures of all teeth were etched using 35% p

Background: Esthetic treatment is the options of patient seeking orthodontic treatment. Therefore this study was conducted to measure the concentration of Aluminum, Nickel, Chromium and Iron ions released from combination of monocrysralline brackets with different arch wires immersed in artificial saliva at different duration, to evaluate the corrosion point on different parts of the orthodontic appliances before and after immersion in artificial saliva, and to evaluate the corrosion potential of each group of the orthodontic appliances. Material and methods: Eighty orthodontic sets prepared. Each set represents half fixed orthodontic appliance, from the central incisor to the first molar, for the maxillary arch, each set consisted of molar

Background:The demand for esthetic orthodontic appliances is increasing so that the esthetic orthodontic archwires were introduced. This in vitro study was designed to evaluate the surface roughness offiber-reinforced polymer composite (FRPC) archwires compared to coated nickel-titanium (NiTi) archwires immersed in artificial saliva. Materials and Methods:Three types of esthetic orthodontic archwires were used: FRPC (Dentaurum), Teflon coated NiTi (Dentaurum) and epoxy coated NiTi (Orthotechnology). They were round (0.018 inch) in cross section and cut into pieces of 15 mm in length.Forty pieces from each type were divided into four groups; one group was left at a dry condition and the other three groups were immersed in artificial saliva (

One hundred isolates of Pseudomonas aeruginosa were obtained from patients admitted to Baghdad hospitals, Iraq during the period between May 2018 until July 2018. These isolates were distributed as 15 isolates from blood, 25 isolates from urinary tract infections, 10 isolates from sputum, 12 isolates from wounds, 15 isolates from ear infections, 15 isolates from bronchial wash of patients suffering from respiratory tract infections in addition to 8 isolates from cystic fibrosis patients. The isolates were initially identified by culturing on MacConkey agar, blood agar and P. aeruginosa agar then diagnosed by performing some morphological and biochemical tests. The second diagnosis was done by API 20E system followed by Vitek 2 compact syste

         The study included evaluation of cell surface charge and hydrophobicity of Escherichia coli, Klebsilla aerogenes, Proteus spp, Bacillus cereus, Staphylococcus epidermidis, Staphylococcus aureus(1) and Staphylococcus aureus(2) were determined by hydrocarbon adherence and hydrophobic interaction chromatography. The results showed that the negative charge of cell surface of gram negative bacteria was much higher than on gram positive once when these bacteria were grown on nutrient agar at 37 c for 18 h . E.coli was more negative charged than Klebsilla aerogenes and Proteus spp. The hydrophobicity of gram positive bacteria was much