Background: Endodontically treated teeth have low resistance to fracture against occlusal forces. The strengthening effect of bonded esthetic onlay restoration on weakened tooth has been reported. This study aimed to assess the fracture resistance of endodontically treated premolars restored with composite with and without cuspal coverage by using direct and indirect techniques. Indirect technique done by CAD/CAM system (computer aided design –computer aided manufacturer) and laboratory processing. Material and methods: Forty human extracted maxillary premolars of approximately comparable sizes were divided into four groups: Group (A): Ten endodontically treated teeth directly filled with Filtek Z250xt without cuspal coverage. Group (B): Ten endodontically treated teeth prepared with onlay cavities and restored directly with Filtek Z250 XT. Group(C): Ten endodontically treated teeth prepared with onlay cavities and restored indirectly with Filtek Z250 XT. Group (D): Ten endodontically treated teeth prepared with onlay cavities and restored indirectly with Paradigm MZ100 CAD/CAM blocks. Fracture strength of the samples was measured by using universal testing machine (an axial compression test). Data were analyzed statistically by one way ANOVA test and least significant difference test, Results showed that Group A has the lowest fracture resistance value than all experimental Groups and the difference are highly significant. While Group B has a high significant fracture resistant value than the indirectly restored groups. Group C and Group D showed an approximate fracture resistant result (1.13KN and 1.07KN respectively) and the difference is statistically not significant. Conclusion All CAD/CAM composite onlay, indirect Filtek z250 XT and direct cuspal coverage survived maximum biting force for posterior single tooth, so these types of onlays provide good reinforcement in an extensive MOD cavities in premolars The mode of fracture for Group D was 90% restorable which is higher than group C (80%) restorable and group B (30%) restorable type of fracture.
Atheism is one of the most dangerous absurd doctrines that have swept the world in the modern era. Its strength lies in the bodies that stand behind it and adopt its ideologies which are accompanied by the tremendous media momentum of the theses of its supporters based on scientific and non-scientific levels. And since the denial of the existence of the Creator is the main focus and central point which the atheists based their view towards the universe, life and man, this humble research came to discuss the claim of the existence of the world by pure chance, and try to explain this scientifically through the theory of natural selection and survival of the fittest developed by the English biologist Charles Darwin. The resea
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The research aims to study the reliability of government institutions, including the audit directors, which are one of the most important oversight formations in the Ministry of Construction, Housing and Public Municipalities, on which the responsibility for comprehensive auditing of all the Ministry's (municipalities) formations falls on the Managing the Audit Program according to the specification (ISO 19011: 2018) to improve the audit performance which requires compliance with the application of the audit management system in accordance with the standard Specification (ISO 19011: 2018), depending on the methodology of the case study, and using of checklists, which were chosen ac
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Abstract: Stars whose initial masses are between (0.89 - 8.0) M☉ go through an Asymptotic Giant Branch (AGB) phase at the end of their life. Which have been evolved from the main sequence phase through Asymptotic Giant Branch (AGB). The calculations were done by adopted Synthetic Model showed the following results: 1- Mass loss on the AGB phase consists of two phases for period (P <500) days and for (P>500) days; 2- the mass loss rate exponentially increases with the pulsation periods; 3- The expansion velocity VAGB for our stars are calculated according to the three assumptions; 4- the terminal velocity depends on several factors likes metallicity and luminosity. The calculations indicated that a super wind phase (S.W) developed on the A
... Show MoreZygapophyseal joints (or facet joints), are a plane synovial joint which located between the articular facet processes of the vertebral arch which is freely guided movable joints. Ten dried vertebrae were used for the lumbar region and taking (L4) as a sample to reveal stress pathways across the joints by using ANSYS program under different loading conditions which used Finite Elements Analysis model. Results obtained from the ANSYS program are important in understanding the boundary conditions for load analysis and the points of stress concentration which explained from the anatomical point of view and linked to muscle and ligament attachments. This model used as a computational tool to joint biomechanics and to prosthetic im
... Show MoreAtheists have spread in the modern era, so that atheism has become a bad phenomenon in the world in general and in Islamic societies in particular, so the research aims to study the individual and social effects left by atheism on the atheists themselves, and the research included multiple axes: atheism linguistically and idiomatically, atheism in the Qur’an Noble and Modern (and Contemporary) Atheism Statistics: and the reasons for atheism: Studying the phenomenon of atheism in Iraq as a model, then studying the effects of atheism: on the individual first, then atheism and its impact on society, then the conclusion, recommendations, sources and references
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The research aims to study strategic training and its impact on improving the performance of the inspectors general offices in Iraqi ministries, through two variables strategic training Which include Four Dimensions ( Strategic analysis , Formulation of Training Strategy , Implement the Training Strategy , Evaluation ) and Performance included Three dimensions ( Efficiency , Effectiveness , Added-Value).
This research problem is that the Offices of Inspectors rely on pre-made training Programs received from training centers without designing the training programs that provide the employees with the skills and abilities that lead to the implementation of the current and future goals of the orga
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