Background: The fracture of instruments within root canal during endodontic treatment is a common incidence, fracture because of fatigue through flexure occurs due to metal fatigue, this study aimed to assess the effect of curvature angle and rotational speed on the cyclic fatigue of different type of Endodontic NiTi Rotary Instruments and compare among them. Materials and method: Three types of rotary instruments with tip size 0.25: ProTaPer F2 (Densply, Malifier) Revo-S SU( 0.06 taper, MicroMega) and RaCe system (0.06 taper, FKG, Dentaire), Forty file of each instrument were used within two canals with angle of curvature (40 &60 )at two speed (250&400)RPM, twelve group were formed for all instruments(total number=120),ten file for each group. The testing canals customized within stainless steel block covered with glass face, the time to fracture recorded and the mean of cycles to fracture (MCF) detected for each instrument. Data were analyzed statistically by ANOVA, LSD and Independent T-test at 5% significant level. Result: there was a highly significant difference of curvature angle and significant difference of rotational speed on the fracture resistance of instruments. RaCe revealed the best fracture resistance followed by ProTaper then Revo-S that showed the less resistance. Conclusion: The rotary instruments more prone to fracture when used at more curvature angle and higher rotational speed, as well as the rotary instruments differ from each other according to manufacturing process, taper, cross section and other factors.
The study was reflection of the impact of the widespread use of polymer Novolak composite reinforced Glass fiber and Asbestos fiber once again with weight fraction 60% on the physical properties, which included (Hardness, Compressive deformation, compressive modulus of elasticity, Flexural modulus of elasticity, Resilience modulus, the maximum of Flexural strength, Flexural strain energy and Shear strength inner layers); it is known how much important the media as a source of bacterial contamination, which contributes directly or indirectly in the process of aging of these materials. These Novolak composite reinforced, prepared by weight fraction of (10%) and (14%) of the Hexamethylene-tetraamine (HMTA) hardener material. It
... Show MoreBACKGROUND: Febrile neutropenia occurs in more than 80% of patients with hematological malignances specially after chemotherapy cycles and an infectious source is identified in approximately 20–30%. Various bacterial, viral, and fungal pathogen contribute to the development of neutropenic fever and without prompt antibiotic therapy mortality rate can be as high as 70%. AIM: The objective of the study was to document the current sites of infection in patients with febrile neutropenia in hematological ward in Baghdad Teaching Hospital, the microorganisms and antibiotic susceptibly in culture positive cases and mortality rate in 1 week and 4 weeks after episode of fever. PATIENTS AND METHODS: One hundred cases of febrile neutrop
... Show MoreAbstract :
The research aims to Estimate the Strength of Strategic Innovation application in terms of application strength , and on the overall level in number of Iraqi Industrial business organizations . After wards determine whether their is differerences among those organizations in application process for the dimensions , and for the overall process .
The Research revealed number of conclusions including that the process of strategic innovation is applied in a good Level , and demonstrates the desier of the industrial companies Leaders to Launch beyond the familiar products , and to provide new products that
... Show MoreBackground: Irrigation of the canal system permits removal of residual tissue in the canal anatomy that cannot be reached by instrumentation of the main canals so the aim of this study was to compare and evaluate the efficiency of conventional irrigation system, endoactivator sonic irrigation system,P5 Newtron Satelec passive ultrasonic irrigation and Endovac irrigation system in removing of dentin debris at three levels of root canals and to compare the percentage of dentin debris among the three levels for each irrigation system. Materials and methods: Forty extracted premolars with approximately straight single root canals were randomly distributed into 4 tested groups of 10 teeth each. All canals were prepared with Protaper Universal ha
... Show MoreA 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)
The Innovation Of Knowledge Is An Important And A Key Element In The Progress And Business Excellence Organizations, Therefore Requires Several Elements To Help Create And Implement And Move The Innovation Process Of Knowledge, Including The Strategic Empowerment Associated With The Element Of The Process Of Strategic Momentum Engine Driven Wheel Continuous Dynamic Innovation, And Focused Research Problem By Measuring The Availability Of Strategic Empowerment When Individuals From By Senior Departments And Ways To Help Organizations To Provide Empowerment Commensurate With The Requirements Of Achieving The Goals Of Time And Place Appropriate For The Individual, And The Importance Of Research Stems From The Importance Of The Varia
... Show MoreThe research investigates the political effect and its directions on the architectural thoughts and its achievements and how can this political system affect all fields of life in communities including architectural urban design. The problem of the research lies in the ambiguity effects of the ideological national directions of the Nazi Party on the architecture and urban design of the city of Berlin, then determining the aims of the research to discuss the concepts of politics and architecture and their relation to the way of thinking that plays a role in the process of design that works on property and achieving the suitable urban environments for those communities. After that, the Nazi's party's thought would be studied and analyzed,
... Show MoreBackground: Stress urinary incontinence is a frequent urological disease in women; it has a great influence on an individual’s wellbeing and places a significant economic strain on any health service. The placement of urodynamic diagnostic tests in the evaluation route is an important clinical research concern in this field.
Objective: to find out whether the duration of stress urinary incontinence is associated with the finding of bladder outlet obstruction in urodynamic study or not.
Subjects and Methods: A descriptive study. With enrolled female patients had symptomatic Stress urinary incontinence as their primary complain. All the included patients w
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