Background: Many types of instruments and techniques are used in the instrumentation of the root canal system. These instruments and techniques may extrude debris beyond the apical foramen and may cause post-instrumentation complications. The aim of this study was to evaluate the amount of apically extruded debris resulted by using 4 types of nickel-titanium instruments (WaveOne, TRUShape 3D conforming files, Hyflex CM, and One Shape files) during endodontic instrumentation. Materials and methods: Forty freshly extracted human mandibular second premolar with straight canals and a single apex were collected for this study. All teeth were cut to similar lengths. Pre-weighted glass vials were used as collecting containers. Samples were randomly divided into four groups with 10 samples in each group: Group A instrumentation by WaveOne reciprocating file, Group B instrumentation by TRUShape 3D rotating files, Group C instrumentation by Hyflex CM rotating files and Group D instrumentation by One Shape rotating file. A total volume of 7 ml of sodium hypochlorite was used for irrigation in each sample. Apical patency confirmed and maintained by a size #15 K-File. All canals were instrumented up to a size #25. After completion of endodontic instrumentation, vials were then stored in an incubator for 5 days at 68o C for dryness. Then vials are weighted again, and the pre-weight subtracted from the post-weight, the weight difference resembled the amount of apically extruded debris from the apical foramen during root canal instrumentation. Data obtained were statistically analysed by using ANOVA and LSD tests. Results: The results showed that the Hyflex CM Group (C) has statistical significant lowest apically extruded debris as compared to other groups of this study (P ≤0.05), while the TRUShape Group (B) has statistical significant lowest apically extruded debris as compared to One Shape Group (D) and WaveOne Group (A), while the WaveOne Group (A) showed the highest value of apically extruded debris (p ≤0.01). The result showed that all groups resulted in apical extrusion of debris. Significance: Although all systems caused apical extrusion of debris and irrigant, continuous rotary instrumentation was associated with less extrusion as compared with the use of reciprocating file system.
The Egyptian labor movement is the oldest trade union movement in the Arab region. Beside, the labor movement in any society is, in fact, only a reflection of the extent of awareness of that class in that society. Such a comparison is based on the degree of social growth the working class has reached. Moreover, the Egyptian working class was characterized by modernity in its inception compared to other social forces and classes. In addition, its development is linked to the level of industrial development of the country. The peasants and craftsmen were the mainstay of production in the Egyptian society over several centuries. The labor union movement also represents the human aspect of the labor force when it encounters and interacts wit
... Show MoreMORALS ARE THE MAIN PILLARS IN HUMAN'S LIFE
There is substantial data supporting the importance of both endogenous and exogenous estrogen in maintaining reproductive health and preventing chronic disease, androgens in women's health are rarely discussed. This is one of the first researches to investigate correlates of blood testosterone concentrations in women with osteopenia, in anticipation of the growing interest in the role of androgens in women's health. A 65 volunteer women were enrolled in the current study, they were divided into two groups, 35 postmenopausal women with osteopenia were in the first group, and the second group contained 30 postmenopausal women without osteopenia as a control. Blood samples were collected from all participants and analyzed for testosterone l
... Show MoreThe concept of insurance policy is one of the concepts that expresses a way to face the risks that a person is exposed to in the field of his life. It is a system that involves a prior agreement between two parties through which the risk is transferred from the second party (the insured) to the first party (the insurer) in return for paying an amount Calculated was able to cover the potential loss according to certain percentages agreed upon between the two parties, and that the main goal of any scientific analysis of the risk is to choose the most appropriate policy or method to confront it, by identifying the risks and ways to address them, and the main goal is to reduce losses and limit the possibility of their occurrence.
In
... Show MoreThe present study aims to show the importance of ESL reading ability in acquiring English as a second language. The study involves 92 college students (males and females) from the Department of English at Nizwa College of Applied Sciences, Sultanate of Oman. They represent two groups, the foundation year students and the first year English majors. A number of tests were used to measure students’ overall proficiency in English as well as their reading ability (i.e., the ability to contribute to the main idea of the text, scanning, skimming, to derive word meanings from context, to use a dictionary to find meanings, definitions, to identify prefixes, antonyms and synonyms). Students’ ability to read was correlated to their proficiency
... Show MoreThe Era of Henry VII is the king who established the Tudor as they ruled England for
(24) years .He made drasfic changes in British Economy and the state of the country was
stable and secure.
Thes economic achievement of make him Qualified to be called The founder of the
modern English History .
On the basis of that significance to study one of the development stages of one of the
developed societies presently, i.e. the English society, this thesis came under the title (The
Internal Policy in England 1509-1547) to examine the overall political, economic and social
positions England passed through. The thesis also indicated the intensive labor state suffered
by the English society with all its sections, especial
Ajloun reserve is the most important reserved areas set up by the Jordanian government to encourage development and ecotourism, is located on the green mountains of Ajloun north of Jordan, was founded in 1989 and follow The Royal Society for the conservation of the natur, an area of 13 km2, and covered with thick forests of oak trees and Butm, maple and others, characterized by the diversity of vital consists of 319 species of medicinal and aromatic plants and wild flowers, and where there are 40 species of birds, 14 species of mammals, 16 reptiles, 5 species of plants registered in the world. The Reserve has a great importance in Jordan ,it is the most reservations attractive to tourists, both internally and externally, and prov
... Show MoreSound effects are considered to be a key element in children’s theatre, for it relays the context and amplifies its understandability, acceptability and its impact on the audience, so it’s a fundamental method in portraying the characters within the idea or the story, to produce the title and content with completeness in its relations that are associated with the rest of the fundamental elements represented in lighting, costumes, dialogue, decoration, etc. And this research included a set of subjects that are related to implementing the sound effects used in the Iraqi children’s theatre plays, chapter one included the problem and the need for studying this subject, as well as its importance and aim, and specifying the basic phrases
... Show MoreThe structure is considered in its scientific formula one of the concepts which complete the architectural image that seeks to take out an effective and attractive structure in contemporary architectural production, especially that the structure -in general- represents strength in addition to delight and functional benefits according to Vitruvius trinity. So, the role of structure depends on making its aesthetical properties able to give efficiency within architectural product. That has come through adoption of intellectual mechanism of structural means and details –as a whole or parts- and focused on structure with the recipient's needs, aesthetical, and sensory purposes in addition to its fundamental role of stabilit
... Show MoreThe purpose of this research is to study the organic planning in the United Industry Alliance, focusing on an applied model. It takes the concept of good planning, and its importance in the overall picture, well into political, economic, and military policy. It also analyzes how the United States has used this year to address the challenges that nationalism targets. The research draws on typical examples to illustrate the differences between researcher and decision effectiveness. It also discusses the factors that lead to the success or failure of dynamic planning, and draws lessons from it in other countries. Finally, the researcher begins to help in planning the goal as a basic tool in enhancing effectiveness.