Predictive Model For Removing Separated Instruments In Root Canal

The aim of the study was to establish a statistical model to predict the success rate of the removal of separated instruments in root canal, identify high-risk factors during treatment, and provide a scientific basis for clinical decision-making . In this retrospective studies, the relevant information were collected in 212 clinical cases of patients aged 18-60 who underwent removal of separated instruments between 2016 and 2024. The study has been approved by the Ethics Committee of our institution. Univariate analysis was used to screen the factors influencing the removal of separated instruments, followed by multivariate logistic regression analysis. Futhermore, it developed a predictive model which accuracy was verified by ROC curve. Root canal curvature, length, material and position of the separated instrument, radicular dentin thickness, tooth position, patient gender, and preoperative complications are all factors influencing the removal successful rate. Among these factors, root canal curvature, length and position of the separated instrument showed higher correlations(P<0.05). A regression equation was established correlating these eight factors. The predicted accuracy rate of the regression equation was 93.1% for successful removal, 73% for failed removal and 89.6% for overall. The curvature of the root canal, the length and position of the separated instrument are key factors influencing the separated instruments removal successful rate. This statistical model can predict the removal successful rate by measuring objective indicators before surgery, providing a quantitative basis for clinical decision-making.