ABSTRACT Background: One of the major problems of all ceramic restorations is their probable fracture against the occlusal forces. The objective of this in vitro study was to evaluate the effect of two gingival finishing lines (90°shoulder and deep chamfer) on the fracture resistance of full contour CAD/CAM and heat press all-ceramic crowns. Materials and Methods: Thirty two maxillary first premolars were prepared to receive full contour CAD/CAM (zolid) and heat press (Cergo Kiss) ceramic crowns using a special paralleling device (Parallel-A-Prep). The teeth were divided into four groups according to the type of finishing line prepared. Each crown was cemented to its corresponding tooth using self-etch, self-adhesive dual cure resin cement. Following storage for 1 week in distilled water at room temperature, teeth were subjected to thermal cycling. Fracture resistance was determined using a universal testing machine, and the samples were investigated microscopically from the point of view of the origin of the failure. Statistical analysis was carried out using the one-way ANOVA and Student’s t-tests. Results: The mean values of fracture resistance for CAD/CAM group showed 1367.250+178.967 N for 90°shoulder margins and 1109.250+252.455 N for the deep chamfer margins. ANOVA test results revealed high significance between and within the groups. The mean values of fracture resistance for heat press group were 548.562+272.471 N for 90°shoulder margins and 247.912+96.995 N for the deep chamfer margins expressing statistical significance. Conclusions: The results of this study pointed to a relationship between the design of the cervical finishing line and the fracture strength of the full CAD/CAM crowns and the full heat press ceramic crowns. Both 90° shoulder and deep chamfer finishing lines are suitable for zolid crowns while the 90° shoulder is more suitable for the Cergo Kiss crowns than the deep chamfer preparation. Key words: Full contour, All-ceramic crowns, CAD/CAM, Heat press, Fracture strength.
The design of the interior spaces process the product of intellectual civilization expresses the prevailing thought, discoverers of principles and beliefs through the sheen reflects the present, and generating languages graphical variety caused a different revolution in design mounting structure, and because of the complex nature of the interior spaces were and we have to be a reflection of cultural reality of being a form of cultural expression and true embodiment of scientific developments prevailing for each stage where she was born, the changes occurring in human thought and then extremism and the discrepancy tastes among individuals all communities factors have caused a change in the design structure involving modernization an
... Show MoreThe study tagged: (The aesthetics of balance and its relationship to the design of the body of the industrial product) discussed the role of balance in the design of industrial products of different shapes, colors and sizes, as well as their function. Based on the research problem that was determined by the following question: What is the relationship between balance and the design of the body of the industrial product? The aim of the research is to: reveal the statement of the effectiveness of the balance in the design of the industrial product body.
The study was defined in four chapters: in the first chapter, a problem, the importance, and the aim of the research were presented. The second chapter contained the theoretical framewor
The low-pressure sprinklers have been widely used to replace the high-pressure impact sprinklers in the lateral move sprinkler irrigation system due to its low operating cost and high efficiency. However, runoff losses under the low-pressure sprinkler irrigation machine can be significant. This study aims to evaluate the performance of the variable pulsed irrigation algorithm (VPIA) in reducing the runoff losses under low-pressure lateral move sprinkler irrigation machine for three different soil types. The VPIA uses the ON-OFF pulsing technique to reduce the runoff losses by controlling the number and width of the pulses considering the soil and the irrigation machine properties. Als
The increase globally fossil fuel consumption as it represents the main source of energy around the world, and the sources of heavy oil more than light, different techniques were used to reduce the viscosity and increase mobility of heavy crude oil. this study focusing on the experimental tests and modeling with Back Feed Forward Artificial Neural Network (BFF-ANN) of the dilution technique to reduce a heavy oil viscosity that was collected from the south- Iraq oil fields using organic solvents, organic diluents with different weight percentage (5, 10 and 20 wt.% ) of (n-heptane, toluene, and a mixture of different ratio
... Show MoreThis study is to investigate the possibility of using activated carbon prepared from Iraqi date-pits (ADP) which are produced from palm trees (Phoenix dactylifera L.) as low-cost reactive material in the permeable reactive barrier (PRB) for treating lead (Pb<sup>+2</sup>) from the contaminated groundwater, and then compare the results experimentally with other common reactive materials such as commercial activated carbon (CAC), zeolite pellets (ZP). Factors influencing sorption such as contact time, initial pH of the solution, sorbent dosage, agitation speed, and initial lead concentration has been studied. Two isotherm models were used for the description of sorption data (Langmuir and Freundlich). The maximum lead sorp
... Show Moreيهدف هذا العمل الى بيان طبيعة العلاقة بين الادارة بالتجوال والتجديد الاستراتيجي ، ومدى تأثير المتغير المستقل في المتغير التابع. تضمنت فقرات الاستبانة بوصفه الأداة الرئيسة لجمع البيانات ثلاث جوانب اساسية، تضمن الاول البيانات الشخصية للمستجيبين، فيما تضمن الجانب الثاني الفقرات الخاصة بمتغير الادارة بالتجوال من خلال خمسة ابعاد، فيما اشتمل الجانب الثالث على فقرات التجديد الاستراتيجي عبر تناول اربعة ابعاد. ي
... Show MoreThis work aims to show the nature of the relationship between management by walking around (the independent variable) and strategic renewal (the dependent variable), as well as it shows the effect of the independent variable on the dependent variable. Questionnaire items were considered the main tool for data collection by three basic aspects. The first involved the personal data of the respondents, while the second included items related to management by walking in five dimensions, and the third is strategic renewal items by addressing four dimensions. The tourism sector, while the community has six Excellent grade hotels was taken into account in this wor
... Show MoreThis research investigates the importance of social accounting and the auditor’s report. It basically checks if there is an impact of social accounting on the auditor’s report at the availability the INTOSAI standards No. (1700 and 1706). The study recruited 105 employees of the Federal Financial Supervision Office in Iraq. Data were collected using questionnaire. The questionnaire validity and reliability were checked to assure the truthfulness of the findings. The study found a positive correlation and a statistically significant effect between the accounting for social responsibility and the auditor’s report. It is necessarily recommended for the auditor and the bodies working in the Board of Supreme Audit to ensure the inclusio
... Show MoreThe study aimed to identify the level of awareness of mental health among the students of the Universities of Palestine Technical and Jerusalem open in the city of Tulkarem from the perspective of the students and the population of the study ( 8091 ) students at the two universities , and selected intentional sample size was ( 445 ) students , and used the tool questionnaire to measure responses of subjects , and the results showed that there are differences depending on the variable sex and was in favor of females , and depending on the variable University , and was in favor of the Al-Quds Open / variable Study level for the benefit of students of second year , did not show statistical differences depending on the variables of c
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