Background: Prophylaxis methods are used to mechanically remove plaque and stain from tooth surfaces; such methods give rise to loss of superficial structure and roughen the surface of composites as a result of their abrasive action. This study was done to assess the effect of three polishing systems on surface texture of new anterior composites after storage in artificial saliva. Materials and methods: A total of 40 Giomer and Tetric®N-Ceram composite discs of 12 mm internal diameter and 3mm height were prepared using a specially designed cylindrical mold and were stored in artificial saliva for one month and then samples were divided into four groups according to surface treatment: Group A (control group):10 specimens received no surface polish and were subdivided into A1 (Giomer) and A2 (Tetric®N-Ceram). Group B: 10 specimens received polishing with Air polishing devise (APD) and were subdivided into B1 (Giomer) and B2 (Tetric®N-Ceram). Group C: 10 specimens received polishing with pumice and brush and were subdivided into C1 (Giomer) and C2 (Tetric®N-Ceram). Group D: 10 specimens were polished with pumice and rubber cup and were subdivided into D1 (Giomer) and D2 (Tetric®N-Ceram). Testing was done by means of profilometer and statistically analyzed using analysis of variance test (ANOVA), LSD and student t-test. Also samples were photographed by special orthoplane camera using light polarizing microscope. Results: The results showed a highly statistical significant difference in surface roughness among Giomer subgroups P<0.05. Also there was a highly significant difference P<0.05 when comparing Tetric subgroups according to type of surface treatment. Furthermore there was non-significant difference P>0.05 between groups according to the type of restorative material used. Conclusion: The use of prophylactic surface treatment significantly increased Giomer and Tetric ceram surface roughness and the use of rotating brush has shown the roughest surface among all other types of prophylactic protocols also Giomer had shown more surface roughness than Tetric ceram although the difference was not significant.
In this study two types of extraction solvents were used to extract the undesirable polyaromatics, the first solvent was furfural which was used today in the Iraqi refineries and the second was NMP (N-methyl-2-pyrrolidone).
The studied effecting variables of extraction are extraction temperature ranged from 70 to 110°C and solvent to oil ratio in the range from 1:1 to 4:1.
The results of this investigation show that the viscosity index of mixed-medium lubricating oil fraction increases with increasing extraction temperature and reaches 107.82 for NMP extraction at extraction temperature 110°C and solvent to oil ratio 4:1, while the viscosity index reaches to 101 for furfural extraction at the same extraction temperature and same
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This study aims to recognize the process of using computer in publicschools in Ma`an governorate in terms of hardware, capabilities, and teachers usage. It also aims to identify the most important obstacles those schools face from a teachers perspective.
The study sample consists of (150) teachers from different disciplines. The researcher prepared two questionnaires related to the research pivotal, then presented to a group of arbitrators to be used in this final form. The data was analyzed statistically and the study concluded that there is a shortage in the computer services provided to teachers, and there is a w
... Show MoreABSTRACT
Threw this research to the following:
1 - Know the impact of strategy Puglia in the collection of the rules of the Arabic language
students at the Institute of preparation parameters .
2 - Know the impact of the retention strategy in Puglia collection rules Arabic language
students at the Institute of preparation parameters .
To verify the status Mmermaa Find researcher Elsafreeten following two hypotheses :
1 - There is no statistically significant difference between the average score for the collection
of the fourth grade students at the Institute for the preparation of material parameters who
were studying grammar strategy Puglia and average grades collectible fourth grade
students at the Institu
This study is taken from the doctoral thesis that I prepared in the year 2000 at the University of Bordeaux in France under the title “ Ali bin Abi Talib Imam and Calif “. This thesis was prepared as a continuation of what the French orientalism Louis Massignon wrote about Islam and his student Henry Corbin, who introduced Europeans to Shiism. This study represents the philosophy of dialogue and the unity of the Islamic Emma as one of the most important methods used by Imam Ali.
Imam Ali established the most beautiful, creative, and most complete rules of human dialogue that preserve the unity of the nation’s fabric and preserves human dignity. Imam Ali referred to basic principles foundations to reach this goals, including
... Show MoreGaining the relationship between the central government and local governments is great importance especially after the expanded functions of the central government and became unable to carry out their works without all that delegate or transfer parts of its powers to lower levels.
The aims of the research is to determine the relationship of the central government with the local government in accordance with the principle of administrative decentralization with the presentation of the competent authorities, the control of local governments, according to the Provincial Council Act No. 21 of 2008 amended.
The research has a problem that has been the relationship of the central
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The Noble Qur’an is the book of God, the Blessed and Exalted, in which is the teachings of God Almighty’s religion, which is Islam, in order for people to unite it and establish servitude to it. The individual and the society alike saw it appropriate to make my opinion alerting the seriousness of this matter, so the research was entitled (The Impact of Sins and Disobedience on the Individual and Society in the Holy Qur’an - Objective Study), knowing that we touched upon some of the effects, which we found it appropriate to mention in this research in the service of the good. Its details came in the Holy Qur’an without referring to others, noting their arrangement in the Holy Qur’an..
Education in it s different levels becomes development in any country. There fore, nations pay great attention to educational systems, because they perceive that preparing human resources is essential to the development of these nations.
The present study deals with the a academic frames which formulate education in each educational system such as educational philosophy , educational aims , educational strategies by which the academic frames are carried out, which is limited to curriculum, teacher preparations, school activities, in addition to guidance and counseling.
This study reaches some conclusion which are derived from the description of the academic and practical frames some suggestion are made for the mechanism which facil