Background: White spot lesion considered as irreversible tooth demineralization presenting challenge to orthodontists during treatment schedules, fluoride was the most successfully used measure to overcome this challenge. Materials and method: A total of forty sound human permanent premolars were used in the present study and categorized into four groups, in one group the teeth were bonded with stainless steel brackets using Resin-modified glass ionomer cement (RMGIC) and the other three groups the teeth were bonded with light cured composite Resilience® (Ortho technology Co., USA). Group A; Acidulated phosphate fluoride (APF) topical gel (Mfg by DEEPAK PRODUCTS, INC, USA), fluoride ion 1.23% applied on examine area for four minute. Group B; RMGIC (GC Fuji Ortho LC, GC Corporation/Japan) used as bracket adhesive. Group C; Stannous and sodium phosphate fluoride gel yielding 0.72% fluoride ion (Mfg. for: dental resources DS-8) (0.4% Stannous fluoride, 1% sodium fluoride), was applied daily through the experimental study. D; the control group represents the conventional bonding procedure with no preventive method. The entire labial surfaces except 2 mm gingival to the bracket were isolated by acid resistance varnish. All the teeth were subjected individually during 30 days in to acid challenge cycle. After longitudinal sectioning of the teeth by using a hard-tissue microtome, the depth of the artificial lesion was estimated by taking the average of three penetration depths at the lesion centre under stereomicroscope. Also the enamel surface was classified according to acid etch pattern. Comparisons of the average caries penetration of the groups were submitted to ANOVA and LSD tests. The statistical significance level was set at p ≤ 0.05. Results: The results revealed that there were statistically significant differences among the tested groups. With different caries reduction abilities, APF group showed 14%, RMGIC Group 49%, group Stannous and sodium phosphate fluoride 39% depth reduction compared to the control group. Conclusions: While all the groups showed caries reduction by different fluoride agents used in this study, the less average lesion depth was found at group B making the RMGIG the best caries fighting fluoride measure.
A particular solution of the two and three dimensional unsteady state thermal or mass diffusion equation is obtained by introducing a combination of variables of the form,
η = (x+y) / √ct , and η = (x+y+z) / √ct, for two and three dimensional equations
respectively. And the corresponding solutions are,
θ (t,x,y) = θ0 erfc (x+y)/√8ct and θ( t,x,y,z) =θ0 erfc (x+y+z/√12ct)
Robot manipulator is a multi-input multi-output system with high complex nonlinear dynamics, requiring an advanced controller in order to track a specific trajectory. In this work, forward and inverse kinematics are presented based on Denavit Hartenberg notation to convert the end effector planned path from cartesian space to joint space and vice versa where a cubic spline interpolation is used for trajectory segments to ensure the continuity in velocity and acceleration. Also, the derived mathematical dynamic model is based on Eular Lagrange energy method to contain the effect of friction and disturbance torques beside the inertia and Coriolis effect. Two types of controller are applied ; the nonlinear computed torque control (CTC
... Show MoreFor modeling a photovoltaic module, it is necessary to calculate the basic parameters which control the current-voltage characteristic curves, that is not provided by the manufacturer. Generally, for mono crystalline silicon module, the shunt resistance is generally high, and it is neglected in this model. In this study, three methods are presented for four parameters model. Explicit simplified method based on an analytical solution, slope method based on manufacturer data, and iterative method based on a numerical resolution. The results obtained for these methods were compared with experimental measured data. The iterative method was more accurate than the other two methods but more complexity. The average deviation of
... Show MoreStatistical methods and statistical decisions making were used to arrange and analyze the primary data to get norms which are used with Geographic Information Systems (GIS) and spatial analysis programs to identify the animals production and poultry units in strategic nutrition channels, also the priorities of food insecurity through the local production and import when there is no capacity for production. The poultry production is one of the most important commodities that satisfy human body protein requirements, also the most important criteria to measure the development and prosperity of nations. The poultry fields of Babylon Governorate are located in Abi Ghareg and Al_Kifil centers according to many criteria or factors such as the popu
... Show MoreThe current research aims to study the extent to which the Independent High Electoral Commission applies to information security risk management by the international standard (ISO / IEC27005) in terms of policies, administrative and technical procedures, and techniques used in managing information security risks, based on the opinions of experts in the sector who occupy positions (General Manager The directorate, department heads and their agents, project managers, heads of divisions, and those authorized to access systems and software). The importance of the research comes by giving a clear picture of the field of information security risk management in the organization in question because of its significant role in identifying risks and s
... Show MoreThis work describes the effect of temperature on the phase transformation of titanium dioxide (TiO2) prepared using metal organic precursors as starting materials. X-ray diffraction (XRD) was used to investigate the structural properties of TiO2 gels calcined at different temperatures (300, 500, 700) ?C. the results showed that the samples have typical peaks of TiO2 polycrystalline brookite nanopowders after calcined at (300 ?C), which confirmed by (111), (121), (200), (012), (131), (220), (040), (231), (132) and (232) diffraction peaks. Also, XRD diffraction spectra showed the presence of crystallites of anatase with low proportion of rutile phase where calcined at (500 ?C), while rutile phase domains at (700 ?C). The crystallite size of
... Show MoreBaghdad city has been faced numerous issues related to freshwater environment deteriorations due to many reasons, mainly was the discharge of wastewater without adequate treatment. Al-Rustamiya Wastewater Treatment Plant (WWTP) have been constructed among many plants in Baghdad city to reduce the amount of wastewater discharged into natural environment and its subsequent adverse effects. This study was conducted to evaluate the performance of the plant which consist of a conventional activated sludge (CAS) and sequencing batch reactors (SBR) systems as secondary treatment units and its ability to meet Iraqi specifications. A reliability level determination and analysis also were conducted to find the plant's stability an
... Show MoreBaghdad city has been faced numerous issues related to freshwater environment deteriorations due to many reasons, mainly was the discharge of wastewater without adequate treatment. Al- Rustamiya Wastewater Treatment Plant (WWTP) have been constructed among many plants in Baghdad city to reduce the amount of wastewater discharged into natural environment and its subsequent adverse effects. This study was conducted to evaluate the performance of the plant which consist of a conventional activated sludge (CAS) and sequencing batch reactors (SBR) systems as secondary treatment units and its ability to meet Iraqi specifications. A reliability level determination and analysis also were conducted to find the plant's stability and its capabi
... Show MoreA total of 200 samples (180 fecal materials and 20 organ samples) were collected from (5 different poultry farms, 10 local poultry shops, 5 houses poultry, 5 Eggs stores shops and 5hand slaughters centers) in Ibb city, Yemen, 2014. According to morphological, cultural, as well as biochemical characterization and serological tests, 59(29.5%) isolates were identified as Salmonella spp. and all Salmonella isolates were categorized by serotype, which comprised of, 37(62.71%) Salmonella Typhimurium serovar, 21(35.59%). Salmonella Enteritidis serovar and 1(1.69%) Salmonella Heidlberg serovar. Antibiotic sensitivity test was done for bacterial isolates and the results showed there were clear differences in antibiotic resistant. Antimicrobial
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