Evaluation of the relationship between different difficulty classes of teeth and post-endodontic treatment pain: Clinic study

Aim: The aim of this study is to evaluate the levels of postoperative pain experienced at specific time intervals (on the 1st, 3rd, 5th, and 7th days) following endodontic treatment in teeth classified as Class 1 (low difficulty), Class 2 (moderate difficulty), and Class 3 (high difficulty) according to the Endodontic Complexity Assessment Tool (E-CAT), and to investigate the potential relationship between case difficulty level and pain intensity. Materials and Methods: A total of 162 patients over the age of 15 who met the inclusion criteria were enrolled in the study. All treatments were performed in a single visit by the same operator. Cases were classified into three groups low (0-5), moderate (6-11), and high (12 and above) difficulty according to the E-CAT form. Postoperative pain levels were assessed using a Visual Analog Scale (VAS) on days 1, 3, 5, and 7 following the procedure. Results: Of the cases, 32.7% were classified as low difficulty, 34.0% as moderate, and 33.3% as high difficulty. A significant positive correlation was found between E-CAT scores and treatment duration (r=0,540, p<0,001). Pain levels decreased over time in all groups. On days 5 and 7, pain persisted in the high-difficulty group, while it completely resolved in the low-difficulty group (p<0.05). No significant relationship was observed between preoperative and postoperative pain levels (p>0.05). However, postoperative pain was significantly higher in teeth with previous restorations and in RT cases (p=0.016). Conclusion: Although increased case complexity has been associated with longer treatment durations and a higher incidence of postoperative pain, no significant difference has been found in pain severity among the difficulty groups. Keywords: Endodontic complexity assessment tool, postoperative pain, root canal treatment, visual analog scale