Frequently affected teeth by different types of iatrogenic perforations made during dental training in Bulgaria

Background: One of the reasons for endodontic treatment failure is iatrogenic perforation. That is why it is important to provide adequate endodontic education for graduating young practitioners. Aim: The aim of this study is to determine the most common locations of the iatrogenic perforations made by last year students in the Dental Faculty in Sofia, Bulgaria, to note the association of particular errors with particular teeth and to determine how this information can improve their education. Methods: All patient records of last-year students for 2015 and 2016 were examined. Perforations were diagnosed by radiography, and also confirmed clinically. Results: From all 778 teeth 30 incidents of root perforations were found: 10 in 2015 and 20 in 2016. More perforations were found in upper posterior teeth- 80% of all the perforations made in 2015, and 45% of all registered perforations in 2016. For the entire period of the research perforation frequency in upper molars, and in upper anterior teeth were found to be significantly higher than in other group of teeth. In academic 2015 year, 8 of the perforations (80%) were furcal. In 2016 year, 11 (55%) of all perforations were apical. Conclusions: More in-depth knowledge of endodontic anatomy , and also more strict supervision on students’ tasks are needed, especially regarding standard root canal treatment on molar teeth.