Background: Root canal obturation length may significantly affect the development of apical periodontitis lesions. This study aimed to investigate the prevalence of periapical periodontitis and its relationship with previous root canal treatment in terms of root canal obturation length.
Materials and Methods: In this cross-sectional observational study, 264 root canal-treated premolars and molars from patients referred to the Faculty of Dentistry at Azad University of Isfahan, who had undergone root canal treatment at least one year prior, were examined using CBCT radiography. A total of 630 canals with previous root canal treatments were selected. The screening protocol involved an initial selection of roots, followed by alignment in three planes (coronal, sagittal, axial) to ensure centrality. The roots were then classified based on the presence of periapical periodontitis and obturation length. Data analysis was conducted using Fisher’s exact test (α=0.05).
Results: There was no significant difference between quality of obturation length among root treated teeth in all study groups (p>0.05). Significant difference was observed between the obturation length and the frequency of apical periodontitis. The lesions among canals with proper obturation length were significantly less than canals with under or over obturation (p<0.001). But no significant difference was shown in pairwise comparison of each teeth type. (molars -premolars, first- second) (P>0.05).
Conclusion: There was a relationship between the length of root canal obturation and the prevalence of apical periodontitis, with a significantly lower presence of lesions in canals with appropriate obturation. However, this relationship was not observed based on the type of teeth.