Background: The use of electronic apex locators for working length determination eliminates many of the problems associated with the radiographic measurements (interference of anatomical structures, errors in projection such as elongation or shortening, and lack of three-dimensional representation). Its most important advantage over radiography is that it measures the length of the root canal to the apical constriction, not to the radiographic apex. The aim of this study was to assess the accuracy of a new fifth generation apex locator (Joypex 5) in recording the apical constriction and comparing it with a third generation apex locator (Root ZX) in vitro. Materials and method: Twenty four single-rooted sound human premolars, extracted for the purpose of orthodontic treatment and with fully-formed roots, were used in this study. Endodontic access cavity was prepared in each tooth and canal patency up to the apical foramen was checked with a #15 stainless steel K-file. No root canal preparation was performed. Root canal length measurement was done directly and electronically using two apex locators (Joypex 5 and Root ZX). Direct measurement of the root canal length was done by introducing a #15 K-file inside the root canal until its tip was just visible at the apical foramen, then removed from the root canal and its length was measured (in mm) and subtracted by 0.5 mm. For electronic measurement, the teeth were fixed in a sponge soaked in saline and the root canals were also filled with saline. The lip electrode was attached to the sponge and the apex locators were used according to the manufacturers' instructions. The file holder was clipped to the metal shaft of a #15 K-file and the file was then inserted inside the root canal and advanced until the display reading on the LCD of the apex locator was "0.5". The file was then removed from the root canal and its length was measured (in mm). The differences between the readings of each apex locator and the actual length of each canal were computed, and the results were analyzed statistically by paired t-test using SPSS Version 13. Results: The results of this study showed that the Joypex 5 apex locator showed a lower mean difference than the Root ZX apex locator as compared with the actual length, which was statistically significant (p<0.05). Concerning the accuracy of the two apex locators, Joypex 5 apex locator recorded the apical constriction exactly in 67%, while the Root ZX apex locator in only 25%. Within ±0.5 mm from the actual length, the accuracy of the Joypex 5 and the Root ZX were 83% and 67%, respectively. Within ±1 mm from the actual length, the accuracy of the Joypex 5 and the Root ZX were 100% and 96%, respectively. Conclusion: The Joypex 5 apex locator which is a fifth generation apex locator was more accurate in recording the apical constriction as compared with the Root ZX apex locator which is a third generation apex locator.
(1)
One of the prominent goals of Metrical Phonology Theory is providing stress of poetry on the syllable-, the foot-, and the phonological word- levels. Analysing poetry is one of the most prominent and controversial issues for the involved number and types of syllables, feet, and meters are stable in poetry compared to other literary texts. The prosodic seeds of the theory have been planted by Firth (1948) in English, while in Arabic يديهارفلا in the second half of the eighth century (A.D.) has done so. Investigating the metrical structure of poetry has been conducted in various languages, whereas scrutinising the metrical structure of English and Arabic poetry has received little attention. This study aims at capturing the
... Show MoreIdentity crisis is a dominant literary theme, especially in most Arab women writers’ works. However, it has not been given enough attention from a linguistic point of view. By so doing, the current study intends to fill this gap by analyzing the identity crisis from a pragma-stylistic perspective by examining the writer's style in three purposely selected extracts from Diana Abu-Jaber’s novel Origin (2007). The study aims to examine the identity crisis by using pragmatic and stylistic tools and to explore the effects of Abu-Jaber’s stylistic choices on the readers of her work. To conduct this study, an eclectic model comprising Searle’s speech acts (1979), Brown and Levinson's politeness theory (1987), Leech's model of figur
... Show More
المستخلص [English] Peace-building is a science that has its foundations and needs mechanisms, components, studies and plans based on the needs of the parties responsible for achieving peace and meeting the necessary needs of conflict societies, as it has become a goal sought by many local and regional actors and parties. The State of South Africa has realized this fact and has devoted space in its conception and planning to addressing the issues of conflict and war within the framework of its unitary work.Since security and stability in general seek to create peaceful and legal means through which existing problems can be expressed and addressed. The differences have varied to build peace and create cooperation between groups and th
... Show More
Abstract
Among the things that have happened and that have emerged from the developments in society is the phenomenon of dairy banks, where institutions collect milk from donating mothers or sellers of milk and benefit from it by sterilizing and selling it.
This topic is considered one of the important topics, as Islam considers breastfeeding as a link as well as parentage, and it has the same genealogy as the spread of sanctity. Therefore, Imamate jurists addressed this topic with research despite its absence in Islamic societies.
The importance of r
... Show MoreThe textbook is the primary means of creativity and thinking, which has a major role in the development of the readership and mental abilities of the student. It is the basic tool in education in Iraq for the teacher and the student, which cannot be dispensed in any educational program. The current study aimed at the book of the biology of the sixth grade of science in Iraq (comparative study). It was compared to the book of biology for the twelve grade in the Kingdom of Jordan to identify the ratio of similarity and differences between them, in addition, to identify the weaknesses in the Iraq curriculum and developing appropriate solutions and suggestions to address them. The sample was represented with books of biology (six-science cla
... Show MoreObjective: To conduct a standardized method for cavity preparation on the palatal surface of rat maxillary molars and to introduce a standardized method for tooth correct alignment within the specimen during the wax embedding procedure to better detect cavity position within the examined slides. Materials and methods: Six male Wistar rats, aged 4-6 weeks, were used. The maxillary molars of three animals were sectioned in the frontal plane to identify the thickness of hard tissue on the palatal surface of the first molar which was (250-300µm). The end-cutting bur (with a cutting head diameter of 0.2mm) was suitable for preparing a dentinal cavity (70-80µm) depth. Cavity preparation was then performed using the same bur on the tooth surf
... Show More
(2)
(2)
(2)
(1)
ASTRACT
The current study aimed to identify the quality of health services provided by the Omani health sector through the comparison between public and private hospitals in Dhofar Governorate, Oman. A questionnaire has been developed to collect data from 360 patients who received health services in one public Hospital (Sultan Qaboos) and three private Hospitals (Badr Al-Sama, Lifeline, and Al-Hakeeim). The data were analyzed using independent samples T-Test and One Way ANOVA. The results of the study showed that the quality levels of health services offered in private hospitals were better than public hospitals. The study results also reveled that there are significant differences between public hospitals and private hos
... Show More
Experimental investigations had been done in this study to demonstrate the effect of natural particles used as a reinforcement material to unsaturated polyester resin. The tensile test and water absorption were investigated according to (ASTM D638) and (ASTM D570), respectively. The influence of sunflower husk and pomegranate husk particles, used as a reinforcement material, on the tensile strength, Young's modulus and water absorption with different weight fraction (3%, 7% and 10%) and particle grain size (50µm, 100 µm and 150 µm), has been investigated. The water absorption of polymer composites was studied by measuring the specimen weight before and after immersion in water for one hundred days. In the experiments of tensile test,
... Show More
(4)