Iranian Dental Association Journal of Iranian Dental Association 3060-8201 21 2 2009 09 01 Reliability of six methods of measuring convergence angle in posterior teeth for single PFM crown 122 126 EN Hamid Jalali Habib Hajmiragha Amirhoseian Bazrpour Saeed Nokar Journal Article 2009 09 13 2013 02 25  Reliability of six methods of measuring convergence angle in posterior teeth for single PFM crown    Dr. Jalali H .,1 Dr. Hajmiragha H .,1 Dr. Bazrpour AH .2 <u>Dr. </u><u>Nokar </u><u>S.</u> 1  1 Assistant Professor, Department of Prosthodontics, School of Dentistry, Tehran University / Medical Sciences. Tehran, Iran. 2 Dentist.  <i> </i> (Received 5 Nov, 2008 Accepted 9 May, 2009)  <i> </i> Abstract    Background and Aim : There are several methods of measuring Convergence Angle in posterior single PFM crown. The aim of the present study was to compare the reliability of these methods.  Materials and Methods : This experimental study was conducted with twenty selected stone dies, numbered 1 to 20. The convergence angles were measured and recorded by five last year dental students using manual and computer assisted methods. The manual methods used were: 1. Photocopy machine, 2. Digital camera, 3. Analogue camera (photography), 4. Overhead projector the computer assisted methods were: 5. Scanner machine and 6. Microscope. Data were analyzed using One Way Random Effect, and SPSS version 11 statistical software.  Results: Coefficient of reliability for methods 1 to 6 was 0.9981, 0.9988, 0.9986, 0.9991, 0.9957, and 0.9994 respectively. No significant difference was detected among these methods and all were found to be reliable.  Conclusion : There were no significant differences among the methods evaluated. Moreover, all methods were found to be significantly reliable and can be used for measuring convergence angles.  Key words : Reliability - Convergence angle - Axial wall inclination - Retention .    Corresponding Author : Dr. Nokar S ., Assistant Professor, Department of Prosthodontics, School of Dentistry, Tehran University / Medical Sciences. Tehran, Iran.  e.mail: noukarsa@sina.tums.ac.ir Â