Introduction: Several investigation have shown that endodontic assistants had problems in performing apical surgeries and without any practical training and only based on theoretical reserves, they started apical surgery in the third year, which caused reduction of the quality of surgeries, high treatment failures, high stress and reduced motivation and self-confidence of residents, prolongation of surgeries, patient harassment and sometimes irreparable mistakes were made on the patient. Therefore, it was decided that continuous steps to solve these problems should start from the pre-clinic and continue until the clinical stage. The aim of the present study was to investigate the improvement of skills, competence and motivation of endodontic assistants in performing periapical surgeries after changes in the pre-clinic of endodontic treatment.
Materials & Methods: Since 2016, changes have been made in the model and method of teaching in apical surgery in the endodontic department of Mashhad Dental School. Based on surveys of endodonticprofessors and assistants, as well as reviewing the quality of treatments, the effectiveness of this new system was evaluated. Therefore, a descriptive cross-sectional study was designed. To assess the satisfaction of residents, questionnaires were distributed among the endodontic residents of Mashhad Dental School from the entrance of 2016 to 2020, and another questionnaires were given to 13 faculty members of the endodontics department. Before distributing the questionnaires, their validity and reliability were checked.
Results: The results of a survey from residents showed 78.3%  increase the quality of treatments, 65% speed of operation and confidence and motivation to perform periapical surgeries independently.According to the professors, the speed of action, mastery and skills of the assistants as well as the patients' satisfaction have increased.
Conclusion: Providing this educational model of periapical surgery has an important role in promoting the training of endodontic assistants and can be included in the educational curriculum.