Association between missed canals and apical periodontitis

The aim of this study was to evaluate the accuracy of imaging methods for detection of apical periodontitis (AP). Imaging records from a consecutive sample of 888 imaging exams of patients with endodontic infection (1508 teeth), including cone beam computed tomography (CBCT) and panoramic and periapical radiographs, were selected. Sensitivity, specificity, predictive values, and accuracy of periapical and panoramic radiographs were calculated. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic accuracy of the panoramic and periapical images. Prevalence of AP was significantly higher with CBCT. Overall sensitivity was 0.55 and 0.28 for periapical and panoramic radiographs, respectively. ROC curves and area under curve (AUC) with periapical radiography showed a high accuracy for the cutoff value of 5 for both periapical (AUC, 0.90) and panoramic (AUC, 0.84) radiographs. AP was correctly identified with conventional methods when showed advanced status. CBCT was proved to be accurate to identify AP.

This study evaluated the prevalence of bacterial biofilms in untreated and treated root canals of teeth evincing apical periodontitis. The associations of biofilms with clinical conditions, radiographic size, and the histopathologic type of apical periodontitis were also investigated. The material comprised biopsy specimens from 106 (64 untreated and 42 treated) roots of teeth with apical periodontitis. Specimens were obtained by apical surgery or extraction and were processed for histopathologic and histobacteriologic techniques. Bacteria were found in all but one specimen. Overall, intraradicular biofilm arrangements were observed in the apical segment of 77% of the root canals (untreated canals: 80%; treated canals: 74%). Biofilms were also seen covering the walls of ramifications and isthmuses. Bacterial biofilms were visualized in 62% and 82% of the root canals of teeth with small and large radiographic lesions, respectively. All canals with very large lesions harbored intraradicular biofilms. Biofilms were significantly associated with epithelialized lesions (cysts and epithelialized granulomas or abscesses) (p 0.05). Extraradicular biofilms were observed in only 6% of the cases. The overall findings are consistent with acceptable criteria to include apical periodontitis in the set of biofilm-induced diseases. Biofilm morphologic structure varied from case to case and no unique pattern for endodontic infections was identified. Biofilms are more likely to be present in association with longstanding pathologic processes, including large lesions and cysts. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

This study intended to examine histologically root canal-treated teeth evincing apical periodontitis lesions and correlate the findings with clinical observations. Specimens were obtained from 24 patients (12 asymptomatic and 12 symptomatic) by extraction or endodontic surgery and consisted of roots or root tips and the associated pathologic lesion. Specimens were processed for histologic analysis, and serial sections were evaluated. Findings were correlated with clinical observations according to the presence or absence of symptoms. The mean period elapsed from treatment to specimen retrieval in the asymptomatic group was 7.5 years, as compared with 2.2 years in the symptomatic group. All specimens exhibited periradicular inflammation. Bacteria were visualized in all cases, except for 1 specimen from the asymptomatic group in which a foreign body reaction to overfilled material was the probable reason for emergent disease in a previously vital case. Irrespective of the presence of symptoms, bacteria were always located within the root canal system, although they were also observed in the periradicular tissues in 1 asymptomatic and 4 symptomatic teeth. In general, intraradicular bacterial colonization was heavier in symptomatic failed teeth. The present findings support the role of intraradicular infections, usually in the form of biofilms, as the primary cause of endodontic treatment failure.