Determination of the incidence of missed canals inretreatment cases performed at Tokat Gaziosmanpaşa University Faculty of dentistry, department of endodontics: A retrospective study

Aim: The aim of this thesis is to retrospectively examine the radiographs of patients who presented to our clinic between 2014 and 2023 with a diagnosis of retreatment, in order to identify the relationship between the failure of previous endodontic treatments and missed canals. Additionally, this study aims to classify this relationship based on the patients' age, gender, and tooth groups. Materials and Methods: A total of 5132 endodontic cases that underwent retreatment treatment in Tokat Gaziosmanpaşa University Faculty of Dentistry, Department of Endodontics between 2014 and 2023 were included in our study. It was determined that there were missed canals in 811 of the analyzed cases. The radiographs of the patients were examined on 27-inch Dell Precision T3620 medical monitors (Dell, Round Rock, TX, USA) with a resolution of 1920 × 1200 pixels and 64-bit color depth. SisoView medical imaging software (Sisoft, Sivas, Turkey) was used to evaluate the images. In cases where an overlooked canal was detected, the localization and type of the tooth, the gender and age of the patients, and the localization of the overlooked canal were recorded. Results: After analyzing 5132 retreatment cases, the incidence of missed canals was 15.8%. The incidence of missed canals was statistically significantly higher in the lower molars (42.5%) and upper molars (29.3%) compared to other tooth groups (p<0.001). It was found to be statistically significant that the second canal in the distal root was more frequently missed in lower first molars (78%), the mesiolingual canal (ML) in lower second molars (47%), the mesiobuccal second canal (MB2) in upper first molars (66%) and the distobuccal canal (DB) in upper second molars (49%) (p<0.001). When the missed canals were compared between age groups, it was found that the number of missed canals was significantly higher in patients aged 25-50 years (p<0.001). Comparison between genders showed that missed canals were significantly higher in women (p<0.001). Conclusion: The incidence of missed canals in molar teeth was observed to be higher compared to other tooth groups. Tooth type (molar), age (25-50), and gender (female) were found to have a significant impact on the incidence of missed canals.