Background: to evaluate the effect of different dentifrices on the surface roughness of two composite resins (nanofilled-based and nanoceramic – based composite resins). Materials and methods: Forty specimens (diameter 12 mm and height of 2mm) prepared from different composite resin materials: Z350 (nanofilled composite, and Ceram-X (nanoceramic) .they were subjected to brushing simulation equivalent to the period of 1 year. The groups assessed were a control group brushed with distilled water (G1), Opalescence whitening toothpasteR (G2), Colgate sensitive pro-relief (G3) and Biomed Charcoal Toothpaste (G4). The initial and final roughness of each group was tested by surface roughness tester. The results were statistically analyzed using

The principle of citizenship has international dimensions that affect the application of the principle, such as the structure of the international system, and the control of the concepts of globalization, international organizations which played an important role in the consolidation of this principle.

The problem of the study revolves around the effects of international variables on the principle of citizenship in Kuwait during the period 1991-2018.

The study used several indicators, such as: the rule of law, achieving the principle of separation of powers, the right to form parties, the application of the law of nationality, and racial discrimination, women's rights, and freedom of expression.

Basic Orientation  and search path in determining the impact of creative thinking in cultural intelligence field research on the doctors competence, as is a theme of creative thinking great importance in spite of being a old , but his role at the individual level and / or organizational a sustainable effect toward developing a fact uncommon , any sense that one of the pillars of modernity and provide a unique future, as is the competitive weapon of the organizations in an environment dubbed fundamental change and provide all that is unfamiliar, and in the center of the field of research and objective measurement of creative thinking on doctors specialists at the construction of a state of the preference and

Abstract The Synthesis in good yields of some new 1,8-Naphthyridine derivatives (1-9) and characterized on the basis of IR and 1H NMR spectra data. The compounds (1) and (6) were utilized as a starting material for the preparing of these compounds.

Stereo lithography (SLA) three-dimensional (3D) printing process is a type of additive manufacturing techniques that uses digital models from computer-aided design to automatically produce customized 3D objects. Around 30 years, it has been widely utilized in the manufacturing, design, engineering, industrial sectors and its applications in dentistry for manufacturing prosthodontics are very important. The stereo lithography technology is highly regarded because it can produce items with excellent precision especially when selecting the best process parameters. This review article offers a useful and scientific summary of SLA three-dimensional printing technology and its brief history. The specific type of 3D printers which is SLA type b