Influence of Root Canal Curvature on the Accuracy of Root ZX Electronic Foramen Locator: An In Vitro Study

Introduction: The aim of this in vitro study was to evaluate the correlation between accuracy of Root ZX electronic foramen locator and root canal curvature. Methods and Materials: One hundred and ten extracted mandibular molars were selected. Access cavity was prepared and coronal enlargement of mesiobuccal canal was performed. A #10 Flexofile was inserted into the mesiobuccal canal, and a radiography was taken to measure the degree of curvature by Schneider's method. The actual working length (AWL) was defined by inserting the file until its tip could be observed at a place tangential to the major apical foramen and then 0.5 mm was subtracted from this measurement. For the electronic working length (EWL) measurement, the apical 3 or 4 mm of the root was embedded in alginate as the electrolyte material. The file was inserted into the root canal to the major foramen, until the APEX reading was shown on the electronic device and then pulled back until the visual display showed the 0.5-mm mark. The AWL was subtracted from the EWL to define the distance between the file tip and the point 0.5 mm coronal to the major apical foramen. Data were analyzed using the Pearson’s correlation coefficient. Results: The accuracy of Root ZX within ±0.1 mm and ±0.5 mm was 38.2% and 94.6%, respectively. There was no correlation between the distance from the EWL to the AWL and the degree of root canal curvature (r=0.097, P=0.317). Conclusion: Root canal curvature did not influence the accuracy of Root ZX foramen locator.Keywords: Accuracy; Curved Root Canals; Electronic Apex Locator; Working Lengt

A social work study on relationship between leadership style and organization change: A case study of Semnan high schools' teachers

The primary objective of this survey is to study the relationship between leadership style among teachers who work in high schools and their orientation on organizational change. The study is performed among students who attended guided schools in province of Semnan, Iran. There are five hypotheses associated with the proposed study of this paper including managers' attitudes on change based on demographic characteristics, the relationship between leadership style and organizational change, the effects of different leadership styles and the organizational change orientation in terms of demographical characteristics. Statistical population includes all teachers who for high schools in city of Semnan, Iran and the study used a sample of 373 people who were randomly selected from three regions of the city. The proposed study used standard leadership questionnaire based on initiating structure and consideration originally developed at Ohio university in two dimensions with 30 questions. The questionnaire also used another type questionnaire consists of 32 questions with three dimensions of structure, technology and employee. The results indicate that there is no meaningful relationship between leadership style and gender, leadership style and job experience, organizational change and gender, management change and gender

A social study on effects of personal characteristics on suicide attempt

Suicide attempt has been one of serious social problems in todays’ modern society and many studies have been focused to detect different factors influencing this unfortunate issue. In this paper, we perform an empirical study among 897 people who had some experiences associated with suicide attempt. We have designed and distributed a questionnaire among them investigating the impact of four major issues including marital status, educational background, age and living status. The results of our survey indicate that married people tend to commit suicide more than single people do. The other observation indicates that more educated people are more likely to commit suicide, older people are more interested in ending their lives and finally, people who live in cities are more likely to commit suicide than other people