Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 5 1 2008 03 15 37 41 H. Dorriz Associate Professor, Department of Prosthodontics, School of Dentistry, Tehran University of Medical S. Nokar Assistant Professor, Department of Prosthodontics, School of Dentistry, Tehran University of Medical R. Baghai Naini Assistant Professor, Department of Prosthodontics, School of Dentistry, Tehran University of Medical A. Madadi Dentist, Private Practice 2015 10 03 Objective: A clinically feasible convergence angle in full-coverage crown preparations, meeting the requirements for proper retention and resistance forms, has always been a matter of interest for laboratory and clinical researches. This study aims to evaluate the angle in teeth prepared by both under- and post-graduate students at Tehran University of Medical Sciences, Faculty of dentistry, Department of Prosthodontics. Materials and Methods: Samples consisted of 196 prepared teeth for full-coverage crown restoration by third year postgraduate and fifth year undergraduate students in the Department of Prosthodontics. Two images were obtained from each die by a scanner and both bucco-lingual and mesio-distal convergence angles were measured, by two different assessors, via Auto CAD 14 software. The data were analyzed using analysis of variance. Results: There were statistically significant differences between the teeth prepared by un-der- and post-graduate students in mesio-distal convergence angles of all maxillary teeth, except for canines. Significant differences were found between bucco-lingual convergence angles of the maxillary canines and molars. Conclusion: The recently recommended convergence angles are more clinically feasible compared to the classic 4 to 10 degrees that was previously suggested for all teeth. It also seems that clinical experience does not necessarily lead to a decrease in convergence an-gles during preparation. https://fid.tums.ac.ir/index.php/fid/article/view/144 https://fid.tums.ac.ir/index.php/fid/article/download/144/144